]> sigrok.org Git - pulseview.git/commitdiff
Implement MathSignal
authorSoeren Apel <redacted>
Tue, 11 Aug 2020 17:51:15 +0000 (19:51 +0200)
committerSoeren Apel <redacted>
Sat, 22 Aug 2020 22:16:19 +0000 (00:16 +0200)
19 files changed:
CMakeLists.txt
README
pv/data/decodesignal.cpp
pv/data/mathsignal.cpp
pv/data/mathsignal.hpp
pv/data/signalbase.cpp
pv/data/signalbase.hpp
pv/exprtk.hpp [new file with mode: 0644]
pv/session.cpp
pv/session.hpp
pv/views/trace/analogsignal.cpp
pv/views/trace/mathsignal.cpp [new file with mode: 0644]
pv/views/trace/mathsignal.hpp [new file with mode: 0644]
pv/views/trace/signal.cpp
pv/views/trace/signal.hpp
pv/views/trace/trace.cpp
pv/views/trace/trace.hpp
pv/views/trace/view.cpp
test/CMakeLists.txt

index aead6ee7e8e19446f5c961d8620b6a08d3de075f..aa5175cc6ae1559fa8970922a22abf1a9492f160 100644 (file)
@@ -286,6 +286,7 @@ set(pulseview_SOURCES
        pv/views/trace/cursorpair.cpp
        pv/views/trace/flag.cpp
        pv/views/trace/header.cpp
+       pv/views/trace/mathsignal.cpp
        pv/views/trace/marginwidget.cpp
        pv/views/trace/logicsignal.cpp
        pv/views/trace/ruler.cpp
@@ -321,6 +322,7 @@ set(pulseview_SOURCES
 
 # This list includes only QObject derived class headers.
 set(pulseview_HEADERS
+       pv/exprtk.hpp
        pv/logging.hpp
        pv/globalsettings.hpp
        pv/mainwindow.hpp
@@ -353,6 +355,7 @@ set(pulseview_HEADERS
        pv/views/trace/flag.hpp
        pv/views/trace/header.hpp
        pv/views/trace/logicsignal.hpp
+       pv/views/trace/mathsignal.hpp
        pv/views/trace/marginwidget.hpp
        pv/views/trace/ruler.hpp
        pv/views/trace/signal.hpp
diff --git a/README b/README
index 96f17ab6fa5ad933b0ec4200a9ed0381f512a266..d4056b3cd33c0d03b1045bfe05e5d6f76a480d68 100644 (file)
--- a/README
+++ b/README
@@ -88,12 +88,17 @@ DarkStyle: Juergen Skrotzky
     MIT license
     https://github.com/Jorgen-VikingGod/Qt-Frameless-Window-DarkStyle#licence
 
-QHexView:
+QHexView: Victor Anjin
   https://github.com/virinext/QHexView
   License:
     MIT license
     https://github.com/virinext/QHexView/blob/master/LICENSE
 
+ExprTk: Arash Partow
+  https://www.partow.net/programming/exprtk/index.html
+  License:
+    MIT license
+
 
 Mailing list
 ------------
index 2c2c58e202f724ec58b62de207e8325c7d508972..a17ea693aaa89d67ca3859751529e84b75b42eb2 100644 (file)
@@ -56,7 +56,8 @@ DecodeSignal::DecodeSignal(pv::Session &session) :
        srd_session_(nullptr),
        logic_mux_data_invalid_(false),
        stack_config_changed_(true),
-       current_segment_id_(0)
+       current_segment_id_(0),
+       error_message_("")
 {
        connect(&session_, SIGNAL(capture_state_changed(int)),
                this, SLOT(on_capture_state_changed(int)));
index 18761682dd2a7768e2ea93be6b3c8e8a1809f0bb..25b8110e07a78c2a9e5cbbea5957ed1ee29a0b6b 100644 (file)
 #include <pv/data/analogsegment.hpp>
 #include <pv/data/signalbase.hpp>
 
+using std::dynamic_pointer_cast;
 using std::make_shared;
+using std::min;
+using std::unique_lock;
 
 namespace pv {
 namespace data {
@@ -38,29 +41,275 @@ const int64_t MathSignal::ChunkLength = 256 * 1024;
 
 MathSignal::MathSignal(pv::Session &session) :
        SignalBase(nullptr, SignalBase::MathChannel),
-       session_(session)
+       session_(session),
+       use_custom_sample_rate_(false),
+       use_custom_sample_count_(false),
+       expression_(""),
+       error_message_(""),
+       exprtk_symbol_table_(nullptr),
+       exprtk_expression_(nullptr),
+       exprtk_parser_(nullptr)
 {
-       shared_ptr<data::Analog> data(new data::Analog());
+       set_name(QString(tr("Math%1")).arg(session_.get_next_signal_index(MathChannel)));
+
+       shared_ptr<Analog> data(new data::Analog());
        set_data(data);
 
-       shared_ptr<data::AnalogSegment> segment = make_shared<data::AnalogSegment>(
-               *data, data->get_segment_count(), session.get_samplerate());
+       connect(&session_, SIGNAL(capture_state_changed(int)),
+               this, SLOT(on_capture_state_changed(int)));
+       connect(&session_, SIGNAL(data_received()),
+               this, SLOT(on_data_received()));
 
-       data->push_segment(segment);
+       expression_ = "sin(2 * pi * t) + cos(t / 2 * pi)";
 }
 
 MathSignal::~MathSignal()
 {
+       reset_generation();
 }
 
 void MathSignal::save_settings(QSettings &settings) const
 {
-       (void)settings;
+       settings.setValue("expression", expression_);
+
+       settings.setValue("custom_sample_rate", (qulonglong)custom_sample_rate_);
+       settings.setValue("custom_sample_count", (qulonglong)custom_sample_count_);
+       settings.setValue("use_custom_sample_rate", use_custom_sample_rate_);
+       settings.setValue("use_custom_sample_count", use_custom_sample_count_);
 }
 
 void MathSignal::restore_settings(QSettings &settings)
 {
-       (void)settings;
+       if (settings.contains("expression"))
+               expression_ = settings.value("expression").toString();
+
+       if (settings.contains("custom_sample_rate"))
+               custom_sample_rate_ = settings.value("custom_sample_rate").toULongLong();
+
+       if (settings.contains("custom_sample_count"))
+               custom_sample_count_ = settings.value("custom_sample_count").toULongLong();
+
+       if (settings.contains("use_custom_sample_rate"))
+               use_custom_sample_rate_ = settings.value("use_custom_sample_rate").toBool();
+
+       if (settings.contains("use_custom_sample_count"))
+               use_custom_sample_count_ = settings.value("use_custom_sample_count").toBool();
+}
+
+QString MathSignal::error_message() const
+{
+       return error_message_;
+}
+
+QString MathSignal::get_expression() const
+{
+       return expression_;
+}
+
+void MathSignal::set_expression(QString expression)
+{
+       expression_ = expression;
+
+       begin_generation();
+}
+
+void MathSignal::set_error_message(QString msg)
+{
+       error_message_ = msg;
+       // TODO Emulate noquote()
+       qDebug().nospace() << name() << ": " << msg;
+}
+
+uint64_t MathSignal::get_working_sample_count(uint32_t segment_id) const
+{
+       // The working sample count is the highest sample number for
+       // which all used signals have data available, so go through all
+       // channels and use the lowest overall sample count of the segment
+
+       int64_t result = std::numeric_limits<int64_t>::max();
+
+       if (use_custom_sample_count_)
+               // A custom sample count implies that only one segment will be created
+               result = (segment_id == 0) ? custom_sample_count_ : 0;
+       else {
+               if (input_signals_.size() > 0) {
+                       for (const shared_ptr<SignalBase> &sb : input_signals_) {
+                               shared_ptr<Analog> a = sb->analog_data();
+                               const uint32_t last_segment = (a->analog_segments().size() - 1);
+                               if (segment_id > last_segment)
+                                       continue;
+                               const shared_ptr<AnalogSegment> segment = a->analog_segments()[segment_id];
+                               result = min(result, (int64_t)segment->get_sample_count());
+                       }
+               } else
+                       result = session_.get_segment_sample_count(segment_id);
+       }
+
+       return result;
+}
+
+void MathSignal::reset_generation()
+{
+       if (gen_thread_.joinable()) {
+               gen_interrupt_ = true;
+               gen_input_cond_.notify_one();
+               gen_thread_.join();
+       }
+
+       data_->clear();
+
+       if (exprtk_symbol_table_) {
+               delete exprtk_symbol_table_;
+               exprtk_symbol_table_ = nullptr;
+       }
+
+       if (exprtk_expression_) {
+               delete exprtk_expression_;
+               exprtk_expression_ = nullptr;
+       }
+
+       if (exprtk_parser_) {
+               delete exprtk_parser_;
+               exprtk_parser_ = nullptr;
+       }
+
+       if (!error_message_.isEmpty()) {
+               error_message_ = QString();
+               // TODO Emulate noquote()
+               qDebug().nospace() << name() << ": Error cleared";
+       }
+}
+
+void MathSignal::begin_generation()
+{
+       reset_generation();
+
+       if (expression_.isEmpty()) {
+               set_error_message(tr("No expression defined, nothing to do"));
+               return;
+       }
+
+       exprtk_symbol_table_ = new exprtk::symbol_table<double>();
+       exprtk_symbol_table_->add_variable("t", exprtk_current_time_);
+       exprtk_symbol_table_->add_variable("s", exprtk_current_sample_);
+       exprtk_symbol_table_->add_constants();
+
+       exprtk_expression_ = new exprtk::expression<double>();
+       exprtk_expression_->register_symbol_table(*exprtk_symbol_table_);
+
+       exprtk_parser_ = new exprtk::parser<double>();
+       exprtk_parser_->compile(expression_.toStdString(), *exprtk_expression_);
+
+       gen_interrupt_ = false;
+       gen_thread_ = std::thread(&MathSignal::generation_proc, this);
+}
+
+void MathSignal::generate_samples(uint32_t segment_id, const uint64_t start_sample,
+       const int64_t sample_count)
+{
+       shared_ptr<Analog> analog = dynamic_pointer_cast<Analog>(data_);
+       shared_ptr<AnalogSegment> segment = analog->analog_segments().at(segment_id);
+
+       const double sample_rate = data_->get_samplerate();
+
+       exprtk_current_sample_ = start_sample;
+
+       float *sample_data = new float[sample_count];
+
+       for (int64_t i = 0; i < sample_count; i++) {
+               exprtk_current_sample_ += 1;
+               exprtk_current_time_ = exprtk_current_sample_ / sample_rate;
+               double value = exprtk_expression_->value();
+               sample_data[i] = value;
+       }
+
+       segment->append_interleaved_samples(sample_data, sample_count, 1);
+
+       delete[] sample_data;
+}
+
+void MathSignal::generation_proc()
+{
+       uint32_t segment_id = 0;
+
+       // Don't do anything until we have a valid sample rate
+       do {
+               if (use_custom_sample_rate_)
+                       data_->set_samplerate(custom_sample_rate_);
+               else
+                       data_->set_samplerate(session_.get_samplerate());
+
+               if (data_->get_samplerate() == 1) {
+                       unique_lock<mutex> gen_input_lock(input_mutex_);
+                       gen_input_cond_.wait(gen_input_lock);
+               }
+       } while ((!gen_interrupt_) && (data_->get_samplerate() == 1));
+
+       if (gen_interrupt_)
+               return;
+
+       shared_ptr<Analog> analog = dynamic_pointer_cast<Analog>(data_);
+
+       // Create initial analog segment
+       shared_ptr<AnalogSegment> output_segment =
+               make_shared<AnalogSegment>(*analog.get(), segment_id, analog->get_samplerate());
+       analog->push_segment(output_segment);
+
+       // Create analog samples
+       do {
+               const uint64_t input_sample_count = get_working_sample_count(segment_id);
+               const uint64_t output_sample_count = output_segment->get_sample_count();
+
+               const uint64_t samples_to_process =
+                       (input_sample_count > output_sample_count) ?
+                       (input_sample_count - output_sample_count) : 0;
+
+               // Process the samples if necessary...
+               if (samples_to_process > 0) {
+                       const uint64_t chunk_sample_count = ChunkLength;
+
+                       uint64_t processed_samples = 0;
+                       do {
+                               const uint64_t start_sample = output_sample_count + processed_samples;
+                               const uint64_t sample_count =
+                                       min(samples_to_process - processed_samples,     chunk_sample_count);
+
+                               generate_samples(segment_id, start_sample, sample_count);
+                               processed_samples += sample_count;
+
+                               // Notify consumers of this signal's data
+                               // TODO Does this work when a conversion is active?
+                               samples_added(segment_id, start_sample, start_sample + processed_samples);
+                       } while (!gen_interrupt_ && (processed_samples < samples_to_process));
+               }
+
+               if (samples_to_process == 0) {
+                       if (segment_id < session_.get_highest_segment_id()) {
+                               // Process next segment
+                               segment_id++;
+
+                               output_segment =
+                                       make_shared<AnalogSegment>(*analog.get(), segment_id, analog->get_samplerate());
+                               analog->push_segment(output_segment);
+                       } else {
+                               // All segments have been processed, wait for more input
+                               unique_lock<mutex> gen_input_lock(input_mutex_);
+                               gen_input_cond_.wait(gen_input_lock);
+                       }
+               }
+
+       } while (!gen_interrupt_);
+}
+
+void MathSignal::on_capture_state_changed(int state)
+{
+       if (state == Session::Running)
+               begin_generation();
+}
+
+void MathSignal::on_data_received()
+{
+       gen_input_cond_.notify_one();
 }
 
 } // namespace data
index 04380cdc813f5d734f9dcaf7c356c0de5cb41747..f8e15d16261ba9ecbe74efe4015ba170241d00f4 100644 (file)
 #ifndef PULSEVIEW_PV_DATA_MATHSIGNAL_HPP
 #define PULSEVIEW_PV_DATA_MATHSIGNAL_HPP
 
-#include <QSettings>
 #include <QString>
 
+#include <pv/exprtk.hpp>
+#include <pv/util.hpp>
 #include <pv/data/analog.hpp>
 #include <pv/data/signalbase.hpp>
-#include <pv/util.hpp>
 
+using std::atomic;
+using std::condition_variable;
+using std::mutex;
 using std::shared_ptr;
 
 namespace pv {
@@ -35,11 +38,12 @@ class Session;
 namespace data {
 
 class SignalBase;
-class SignalData;
 
 class MathSignal : public SignalBase
 {
        Q_OBJECT
+       Q_PROPERTY(QString expression READ get_expression WRITE set_expression NOTIFY expression_changed)
+       Q_PROPERTY(QString error_message READ error_message)
 
 private:
        static const int64_t ChunkLength;
@@ -51,6 +55,30 @@ public:
        virtual void save_settings(QSettings &settings) const;
        virtual void restore_settings(QSettings &settings);
 
+       QString error_message() const;
+
+       QString get_expression() const;
+       void set_expression(QString expression);
+
+private:
+       void set_error_message(QString msg);
+
+       /**
+        * Returns the number of samples that can be worked on,
+        * i.e. the number of samples where samples are available
+        * for all connected channels.
+        * If the math signal uses no input channels, this is the
+        * number of samples in the session.
+        */
+       uint64_t get_working_sample_count(uint32_t segment_id) const;
+
+       void reset_generation();
+       void begin_generation();
+
+       void generate_samples(uint32_t segment_id, const uint64_t start_sample,
+               const int64_t sample_count);
+       void generation_proc();
+
 Q_SIGNALS:
        void samples_cleared();
 
@@ -59,19 +87,34 @@ Q_SIGNALS:
 
        void min_max_changed(float min, float max);
 
-//private Q_SLOTS:
-//     void on_data_cleared();
-//     void on_data_received();
-
-//     void on_samples_added(SharedPtrToSegment segment, uint64_t start_sample,
-//             uint64_t end_sample);
+       void expression_changed(QString expression);
 
-//     void on_min_max_changed(float min, float max);
+private Q_SLOTS:
+       void on_capture_state_changed(int state);
+       void on_data_received();
 
 private:
        pv::Session &session_;
 
+       uint64_t custom_sample_rate_;
+       uint64_t custom_sample_count_;
+       bool use_custom_sample_rate_, use_custom_sample_count_;
+       vector< shared_ptr<SignalBase>> input_signals_;
+
+       QString expression_;
+
        QString error_message_;
+
+       mutable mutex input_mutex_;
+       mutable condition_variable gen_input_cond_;
+
+       std::thread gen_thread_;
+       atomic<bool> gen_interrupt_;
+
+       exprtk::symbol_table<double> *exprtk_symbol_table_;
+       exprtk::expression<double> *exprtk_expression_;
+       exprtk::parser<double> *exprtk_parser_;
+       double exprtk_current_time_, exprtk_current_sample_;
 };
 
 } // namespace data
index f49d95ebe8b0206f9f020dc0cba4bc7dd7ae1493..7d420ac7017902e8cffa80aee9be976f1fa75e67 100644 (file)
@@ -118,6 +118,12 @@ shared_ptr<sigrok::Channel> SignalBase::channel() const
        return channel_;
 }
 
+bool SignalBase::is_generated() const
+{
+       // Only signals associated with a device have a corresponding sigrok channel
+       return channel_ == nullptr;
+}
+
 bool SignalBase::enabled() const
 {
        return (channel_) ? channel_->enabled() : true;
@@ -571,7 +577,8 @@ void SignalBase::convert_single_segment_range(AnalogSegment *asegment,
                uint8_t *lsamples = new uint8_t[ConversionBlockSize];
 
                vector<shared_ptr<sigrok::Channel> > channels;
-               channels.push_back(channel_);
+               if (channel_)
+                       channels.push_back(channel_);
 
                vector<const sigrok::QuantityFlag*> mq_flags;
                const sigrok::Quantity * const mq = sigrok::Quantity::VOLTAGE;
index 7d7a795e5f8648bf649fa46345d5a679a930c510..5a35218f3a2501e87d5e27ef8656532f27191e74 100644 (file)
@@ -128,6 +128,11 @@ public:
         */
        shared_ptr<sigrok::Channel> channel() const;
 
+       /**
+        * Returns whether this channel is generated or a channel associated with the device.
+        */
+       bool is_generated() const;
+
        /**
         * Returns enabled status of this channel.
         */
diff --git a/pv/exprtk.hpp b/pv/exprtk.hpp
new file mode 100644 (file)
index 0000000..ca38375
--- /dev/null
@@ -0,0 +1,39050 @@
+/*
+ ******************************************************************
+ *           C++ Mathematical Expression Toolkit Library          *
+ *                                                                *
+ * Author: Arash Partow (1999-2020)                               *
+ * URL: http://www.partow.net/programming/exprtk/index.html       *
+ *                                                                *
+ * Copyright notice:                                              *
+ * Free use of the C++ Mathematical Expression Toolkit Library is *
+ * permitted under the guidelines and in accordance with the most *
+ * current version of the MIT License.                            *
+ * http://www.opensource.org/licenses/MIT                         *
+ *                                                                *
+ * Example expressions:                                           *
+ * (00) (y + x / y) * (x - y / x)                                 *
+ * (01) (x^2 / sin(2 * pi / y)) - x / 2                           *
+ * (02) sqrt(1 - (x^2))                                           *
+ * (03) 1 - sin(2 * x) + cos(pi / y)                              *
+ * (04) a * exp(2 * t) + c                                        *
+ * (05) if(((x + 2) == 3) and ((y + 5) <= 9),1 + w, 2 / z)        *
+ * (06) (avg(x,y) <= x + y ? x - y : x * y) + 2 * pi / x          *
+ * (07) z := x + sin(2 * pi / y)                                  *
+ * (08) u := 2 * (pi * z) / (w := x + cos(y / pi))                *
+ * (09) clamp(-1,sin(2 * pi * x) + cos(y / 2 * pi),+1)            *
+ * (10) inrange(-2,m,+2) == if(({-2 <= m} and [m <= +2]),1,0)     *
+ * (11) (2sin(x)cos(2y)7 + 1) == (2 * sin(x) * cos(2*y) * 7 + 1)  *
+ * (12) (x ilike 's*ri?g') and [y < (3 z^7 + w)]                  *
+ *                                                                *
+ ******************************************************************
+*/
+
+
+#ifndef INCLUDE_EXPRTK_HPP
+#define INCLUDE_EXPRTK_HPP
+
+
+#include <algorithm>
+#include <cctype>
+#include <cmath>
+#include <complex>
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+#include <deque>
+#include <exception>
+#include <functional>
+#include <iterator>
+#include <limits>
+#include <list>
+#include <map>
+#include <set>
+#include <stack>
+#include <stdexcept>
+#include <string>
+#include <utility>
+#include <vector>
+
+
+namespace exprtk
+{
+   #ifdef exprtk_enable_debugging
+     #define exprtk_debug(params) printf params
+   #else
+     #define exprtk_debug(params) (void)0
+   #endif
+
+   #define exprtk_error_location             \
+   "exprtk.hpp:" + details::to_str(__LINE__) \
+
+   #if defined(__GNUC__) && (__GNUC__  >= 7)
+
+      #define exprtk_disable_fallthrough_begin                      \
+      _Pragma ("GCC diagnostic push")                               \
+      _Pragma ("GCC diagnostic ignored \"-Wimplicit-fallthrough\"") \
+
+      #define exprtk_disable_fallthrough_end                        \
+      _Pragma ("GCC diagnostic pop")                                \
+
+   #else
+      #define exprtk_disable_fallthrough_begin (void)0;
+      #define exprtk_disable_fallthrough_end   (void)0;
+   #endif
+
+   namespace details
+   {
+      typedef unsigned char            uchar_t;
+      typedef char                      char_t;
+      typedef uchar_t*               uchar_ptr;
+      typedef char_t*                 char_ptr;
+      typedef uchar_t const*        uchar_cptr;
+      typedef char_t const*          char_cptr;
+      typedef unsigned long long int _uint64_t;
+      typedef long long int           _int64_t;
+
+      inline bool is_whitespace(const char_t c)
+      {
+         return (' '  == c) || ('\n' == c) ||
+                ('\r' == c) || ('\t' == c) ||
+                ('\b' == c) || ('\v' == c) ||
+                ('\f' == c) ;
+      }
+
+      inline bool is_operator_char(const char_t c)
+      {
+         return ('+' == c) || ('-' == c) ||
+                ('*' == c) || ('/' == c) ||
+                ('^' == c) || ('<' == c) ||
+                ('>' == c) || ('=' == c) ||
+                (',' == c) || ('!' == c) ||
+                ('(' == c) || (')' == c) ||
+                ('[' == c) || (']' == c) ||
+                ('{' == c) || ('}' == c) ||
+                ('%' == c) || (':' == c) ||
+                ('?' == c) || ('&' == c) ||
+                ('|' == c) || (';' == c) ;
+      }
+
+      inline bool is_letter(const char_t c)
+      {
+         return (('a' <= c) && (c <= 'z')) ||
+                (('A' <= c) && (c <= 'Z')) ;
+      }
+
+      inline bool is_digit(const char_t c)
+      {
+         return ('0' <= c) && (c <= '9');
+      }
+
+      inline bool is_letter_or_digit(const char_t c)
+      {
+         return is_letter(c) || is_digit(c);
+      }
+
+      inline bool is_left_bracket(const char_t c)
+      {
+         return ('(' == c) || ('[' == c) || ('{' == c);
+      }
+
+      inline bool is_right_bracket(const char_t c)
+      {
+         return (')' == c) || (']' == c) || ('}' == c);
+      }
+
+      inline bool is_bracket(const char_t c)
+      {
+         return is_left_bracket(c) || is_right_bracket(c);
+      }
+
+      inline bool is_sign(const char_t c)
+      {
+         return ('+' == c) || ('-' == c);
+      }
+
+      inline bool is_invalid(const char_t c)
+      {
+         return !is_whitespace   (c) &&
+                !is_operator_char(c) &&
+                !is_letter       (c) &&
+                !is_digit        (c) &&
+                ('.'  != c)          &&
+                ('_'  != c)          &&
+                ('$'  != c)          &&
+                ('~'  != c)          &&
+                ('\'' != c);
+      }
+
+      #ifndef exprtk_disable_caseinsensitivity
+      inline void case_normalise(std::string& s)
+      {
+         for (std::size_t i = 0; i < s.size(); ++i)
+         {
+            s[i] = static_cast<std::string::value_type>(std::tolower(s[i]));
+         }
+      }
+
+      inline bool imatch(const char_t c1, const char_t c2)
+      {
+         return std::tolower(c1) == std::tolower(c2);
+      }
+
+      inline bool imatch(const std::string& s1, const std::string& s2)
+      {
+         if (s1.size() == s2.size())
+         {
+            for (std::size_t i = 0; i < s1.size(); ++i)
+            {
+               if (std::tolower(s1[i]) != std::tolower(s2[i]))
+               {
+                  return false;
+               }
+            }
+
+            return true;
+         }
+
+         return false;
+      }
+
+      struct ilesscompare
+      {
+         inline bool operator() (const std::string& s1, const std::string& s2) const
+         {
+            const std::size_t length = std::min(s1.size(),s2.size());
+
+            for (std::size_t i = 0; i < length;  ++i)
+            {
+               const char_t c1 = static_cast<char>(std::tolower(s1[i]));
+               const char_t c2 = static_cast<char>(std::tolower(s2[i]));
+
+               if (c1 > c2)
+                  return false;
+               else if (c1 < c2)
+                  return true;
+            }
+
+            return s1.size() < s2.size();
+         }
+      };
+
+      #else
+      inline void case_normalise(std::string&)
+      {}
+
+      inline bool imatch(const char_t c1, const char_t c2)
+      {
+         return c1 == c2;
+      }
+
+      inline bool imatch(const std::string& s1, const std::string& s2)
+      {
+         return s1 == s2;
+      }
+
+      struct ilesscompare
+      {
+         inline bool operator() (const std::string& s1, const std::string& s2) const
+         {
+            return s1 < s2;
+         }
+      };
+      #endif
+
+      inline bool is_valid_sf_symbol(const std::string& symbol)
+      {
+         // Special function: $f12 or $F34
+         return (4 == symbol.size())  &&
+                ('$' == symbol[0])    &&
+                imatch('f',symbol[1]) &&
+                is_digit(symbol[2])   &&
+                is_digit(symbol[3]);
+      }
+
+      inline const char_t& front(const std::string& s)
+      {
+         return s[0];
+      }
+
+      inline const char_t& back(const std::string& s)
+      {
+         return s[s.size() - 1];
+      }
+
+      inline std::string to_str(int i)
+      {
+         if (0 == i)
+            return std::string("0");
+
+         std::string result;
+
+         if (i < 0)
+         {
+            for ( ; i; i /= 10)
+            {
+               result += '0' + char(-(i % 10));
+            }
+
+            result += '-';
+         }
+         else
+         {
+            for ( ; i; i /= 10)
+            {
+               result += '0' + char(i % 10);
+            }
+         }
+
+         std::reverse(result.begin(), result.end());
+
+         return result;
+      }
+
+      inline std::string to_str(std::size_t i)
+      {
+         return to_str(static_cast<int>(i));
+      }
+
+      inline bool is_hex_digit(const std::string::value_type digit)
+      {
+         return (('0' <= digit) && (digit <= '9')) ||
+                (('A' <= digit) && (digit <= 'F')) ||
+                (('a' <= digit) && (digit <= 'f')) ;
+      }
+
+      inline uchar_t hex_to_bin(uchar_t h)
+      {
+         if (('0' <= h) && (h <= '9'))
+            return (h - '0');
+         else
+            return static_cast<unsigned char>(std::toupper(h) - 'A');
+      }
+
+      template <typename Iterator>
+      inline void parse_hex(Iterator& itr, Iterator end, std::string::value_type& result)
+      {
+         if (
+              (end !=  (itr    )) &&
+              (end !=  (itr + 1)) &&
+              (end !=  (itr + 2)) &&
+              (end !=  (itr + 3)) &&
+              ('0' == *(itr    )) &&
+              (
+                ('x' == *(itr + 1)) ||
+                ('X' == *(itr + 1))
+              ) &&
+              (is_hex_digit(*(itr + 2))) &&
+              (is_hex_digit(*(itr + 3)))
+            )
+         {
+            result = hex_to_bin(static_cast<uchar_t>(*(itr + 2))) << 4 |
+                     hex_to_bin(static_cast<uchar_t>(*(itr + 3))) ;
+            itr += 3;
+         }
+         else
+            result = '\0';
+      }
+
+      inline void cleanup_escapes(std::string& s)
+      {
+         typedef std::string::iterator str_itr_t;
+
+         str_itr_t itr1 = s.begin();
+         str_itr_t itr2 = s.begin();
+         str_itr_t end  = s.end  ();
+
+         std::size_t removal_count  = 0;
+
+         while (end != itr1)
+         {
+            if ('\\' == (*itr1))
+            {
+               ++removal_count;
+
+               if (end == ++itr1)
+                  break;
+               else if ('\\' != (*itr1))
+               {
+                  switch (*itr1)
+                  {
+                     case 'n' : (*itr1) = '\n'; break;
+                     case 'r' : (*itr1) = '\r'; break;
+                     case 't' : (*itr1) = '\t'; break;
+                     case '0' : parse_hex(itr1, end, (*itr1));
+                                removal_count += 3;
+                                break;
+                  }
+
+                  continue;
+               }
+            }
+
+            if (itr1 != itr2)
+            {
+               (*itr2) = (*itr1);
+            }
+
+            ++itr1;
+            ++itr2;
+         }
+
+         s.resize(s.size() - removal_count);
+      }
+
+      class build_string
+      {
+      public:
+
+         build_string(const std::size_t& initial_size = 64)
+         {
+            data_.reserve(initial_size);
+         }
+
+         inline build_string& operator << (const std::string& s)
+         {
+            data_ += s;
+            return (*this);
+         }
+
+         inline build_string& operator << (char_cptr s)
+         {
+            data_ += std::string(s);
+            return (*this);
+         }
+
+         inline operator std::string () const
+         {
+            return data_;
+         }
+
+         inline std::string as_string() const
+         {
+            return data_;
+         }
+
+      private:
+
+         std::string data_;
+      };
+
+      static const std::string reserved_words[] =
+                                  {
+                                    "break",  "case",  "continue",  "default",  "false",  "for",
+                                    "if", "else", "ilike",  "in", "like", "and",  "nand", "nor",
+                                    "not",  "null",  "or",   "repeat", "return",  "shl",  "shr",
+                                    "swap", "switch", "true",  "until", "var",  "while", "xnor",
+                                    "xor", "&", "|"
+                                  };
+
+      static const std::size_t reserved_words_size = sizeof(reserved_words) / sizeof(std::string);
+
+      static const std::string reserved_symbols[] =
+                                  {
+                                    "abs",  "acos",  "acosh",  "and",  "asin",  "asinh", "atan",
+                                    "atanh", "atan2", "avg",  "break", "case", "ceil",  "clamp",
+                                    "continue",   "cos",   "cosh",   "cot",   "csc",  "default",
+                                    "deg2grad",  "deg2rad",   "equal",  "erf",   "erfc",  "exp",
+                                    "expm1",  "false",   "floor",  "for",   "frac",  "grad2deg",
+                                    "hypot", "iclamp", "if",  "else", "ilike", "in",  "inrange",
+                                    "like",  "log",  "log10", "log2",  "logn",  "log1p", "mand",
+                                    "max", "min",  "mod", "mor",  "mul", "ncdf",  "nand", "nor",
+                                    "not",   "not_equal",   "null",   "or",   "pow",  "rad2deg",
+                                    "repeat", "return", "root", "round", "roundn", "sec", "sgn",
+                                    "shl", "shr", "sin", "sinc", "sinh", "sqrt",  "sum", "swap",
+                                    "switch", "tan",  "tanh", "true",  "trunc", "until",  "var",
+                                    "while", "xnor", "xor", "&", "|"
+                                  };
+
+      static const std::size_t reserved_symbols_size = sizeof(reserved_symbols) / sizeof(std::string);
+
+      static const std::string base_function_list[] =
+                                  {
+                                    "abs", "acos",  "acosh", "asin",  "asinh", "atan",  "atanh",
+                                    "atan2",  "avg",  "ceil",  "clamp",  "cos",  "cosh",  "cot",
+                                    "csc",  "equal",  "erf",  "erfc",  "exp",  "expm1", "floor",
+                                    "frac", "hypot", "iclamp",  "like", "log", "log10",  "log2",
+                                    "logn", "log1p", "mand", "max", "min", "mod", "mor",  "mul",
+                                    "ncdf",  "pow",  "root",  "round",  "roundn",  "sec", "sgn",
+                                    "sin", "sinc", "sinh", "sqrt", "sum", "swap", "tan", "tanh",
+                                    "trunc",  "not_equal",  "inrange",  "deg2grad",   "deg2rad",
+                                    "rad2deg", "grad2deg"
+                                  };
+
+      static const std::size_t base_function_list_size = sizeof(base_function_list) / sizeof(std::string);
+
+      static const std::string logic_ops_list[] =
+                                  {
+                                    "and", "nand", "nor", "not", "or",  "xnor", "xor", "&", "|"
+                                  };
+
+      static const std::size_t logic_ops_list_size = sizeof(logic_ops_list) / sizeof(std::string);
+
+      static const std::string cntrl_struct_list[] =
+                                  {
+                                     "if", "switch", "for", "while", "repeat", "return"
+                                  };
+
+      static const std::size_t cntrl_struct_list_size = sizeof(cntrl_struct_list) / sizeof(std::string);
+
+      static const std::string arithmetic_ops_list[] =
+                                  {
+                                    "+", "-", "*", "/", "%", "^"
+                                  };
+
+      static const std::size_t arithmetic_ops_list_size = sizeof(arithmetic_ops_list) / sizeof(std::string);
+
+      static const std::string assignment_ops_list[] =
+                                  {
+                                    ":=", "+=", "-=",
+                                    "*=", "/=", "%="
+                                  };
+
+      static const std::size_t assignment_ops_list_size = sizeof(assignment_ops_list) / sizeof(std::string);
+
+      static const std::string inequality_ops_list[] =
+                                  {
+                                     "<",  "<=", "==",
+                                     "=",  "!=", "<>",
+                                    ">=",  ">"
+                                  };
+
+      static const std::size_t inequality_ops_list_size = sizeof(inequality_ops_list) / sizeof(std::string);
+
+      inline bool is_reserved_word(const std::string& symbol)
+      {
+         for (std::size_t i = 0; i < reserved_words_size; ++i)
+         {
+            if (imatch(symbol, reserved_words[i]))
+            {
+               return true;
+            }
+         }
+
+         return false;
+      }
+
+      inline bool is_reserved_symbol(const std::string& symbol)
+      {
+         for (std::size_t i = 0; i < reserved_symbols_size; ++i)
+         {
+            if (imatch(symbol, reserved_symbols[i]))
+            {
+               return true;
+            }
+         }
+
+         return false;
+      }
+
+      inline bool is_base_function(const std::string& function_name)
+      {
+         for (std::size_t i = 0; i < base_function_list_size; ++i)
+         {
+            if (imatch(function_name, base_function_list[i]))
+            {
+               return true;
+            }
+         }
+
+         return false;
+      }
+
+      inline bool is_control_struct(const std::string& cntrl_strct)
+      {
+         for (std::size_t i = 0; i < cntrl_struct_list_size; ++i)
+         {
+            if (imatch(cntrl_strct, cntrl_struct_list[i]))
+            {
+               return true;
+            }
+         }
+
+         return false;
+      }
+
+      inline bool is_logic_opr(const std::string& lgc_opr)
+      {
+         for (std::size_t i = 0; i < logic_ops_list_size; ++i)
+         {
+            if (imatch(lgc_opr, logic_ops_list[i]))
+            {
+               return true;
+            }
+         }
+
+         return false;
+      }
+
+      struct cs_match
+      {
+         static inline bool cmp(const char_t c0, const char_t c1)
+         {
+            return (c0 == c1);
+         }
+      };
+
+      struct cis_match
+      {
+         static inline bool cmp(const char_t c0, const char_t c1)
+         {
+            return (std::tolower(c0) == std::tolower(c1));
+         }
+      };
+
+      template <typename Iterator, typename Compare>
+      inline bool match_impl(const Iterator pattern_begin,
+                             const Iterator pattern_end  ,
+                             const Iterator data_begin   ,
+                             const Iterator data_end     ,
+                             const typename std::iterator_traits<Iterator>::value_type& zero_or_more,
+                             const typename std::iterator_traits<Iterator>::value_type& zero_or_one )
+      {
+         const Iterator null_itr(0);
+
+         Iterator d_itr    = data_begin;
+         Iterator p_itr    = pattern_begin;
+         Iterator tb_p_itr = null_itr;
+         Iterator tb_d_itr = null_itr;
+
+         while (d_itr != data_end)
+         {
+            if (zero_or_more == *p_itr)
+            {
+               while ((pattern_end != p_itr) && ((zero_or_more == *p_itr) || (zero_or_one == *p_itr)))
+               {
+                  ++p_itr;
+               }
+
+               if (pattern_end == p_itr)
+                  return true;
+
+               const typename std::iterator_traits<Iterator>::value_type c = *(p_itr);
+
+               while ((data_end != d_itr) && !Compare::cmp(c,*d_itr))
+               {
+                  ++d_itr;
+               }
+
+               tb_p_itr = p_itr;
+               tb_d_itr = d_itr;
+
+               continue;
+            }
+            else if (!Compare::cmp(*p_itr, *d_itr) && (zero_or_one != *p_itr))
+            {
+               if (null_itr == tb_d_itr)
+                  return false;
+
+               d_itr = tb_d_itr++;
+               p_itr = tb_p_itr;
+
+               continue;
+            }
+
+            ++p_itr;
+            ++d_itr;
+         }
+
+         while ((pattern_end != p_itr) && ((zero_or_more == *p_itr) || (zero_or_one == *p_itr)))
+         {
+            ++p_itr;
+         }
+
+         return (pattern_end == p_itr);
+      }
+
+      inline bool wc_match(const std::string& wild_card,
+                           const std::string& str)
+      {
+         return match_impl<char_cptr,cs_match>(wild_card.data(),
+                                               wild_card.data() + wild_card.size(),
+                                               str.data(),
+                                               str.data() + str.size(),
+                                               '*',
+                                               '?');
+      }
+
+      inline bool wc_imatch(const std::string& wild_card,
+                            const std::string& str)
+      {
+         return match_impl<char_cptr,cis_match>(wild_card.data(),
+                                                wild_card.data() + wild_card.size(),
+                                                str.data(),
+                                                str.data() + str.size(),
+                                                '*',
+                                                '?');
+      }
+
+      inline bool sequence_match(const std::string& pattern,
+                                 const std::string& str,
+                                 std::size_t&       diff_index,
+                                 char_t&            diff_value)
+      {
+         if (str.empty())
+         {
+            return ("Z" == pattern);
+         }
+         else if ('*' == pattern[0])
+            return false;
+
+         typedef std::string::const_iterator itr_t;
+
+         itr_t p_itr = pattern.begin();
+         itr_t s_itr = str    .begin();
+
+         itr_t p_end = pattern.end();
+         itr_t s_end = str    .end();
+
+         while ((s_end != s_itr) && (p_end != p_itr))
+         {
+            if ('*' == (*p_itr))
+            {
+               const char_t target = static_cast<char>(std::toupper(*(p_itr - 1)));
+
+               if ('*' == target)
+               {
+                  diff_index = static_cast<std::size_t>(std::distance(str.begin(),s_itr));
+                  diff_value = static_cast<char>(std::toupper(*p_itr));
+
+                  return false;
+               }
+               else
+                  ++p_itr;
+
+               while (s_itr != s_end)
+               {
+                  if (target != std::toupper(*s_itr))
+                     break;
+                  else
+                     ++s_itr;
+               }
+
+               continue;
+            }
+            else if (
+                      ('?' != *p_itr) &&
+                      std::toupper(*p_itr) != std::toupper(*s_itr)
+                    )
+            {
+               diff_index = static_cast<std::size_t>(std::distance(str.begin(),s_itr));
+               diff_value = static_cast<char>(std::toupper(*p_itr));
+
+               return false;
+            }
+
+            ++p_itr;
+            ++s_itr;
+         }
+
+         return (
+                  (s_end == s_itr) &&
+                  (
+                    (p_end ==  p_itr) ||
+                    ('*'   == *p_itr)
+                  )
+                );
+      }
+
+      static const double pow10[] = {
+                                      1.0,
+                                      1.0E+001, 1.0E+002, 1.0E+003, 1.0E+004,
+                                      1.0E+005, 1.0E+006, 1.0E+007, 1.0E+008,
+                                      1.0E+009, 1.0E+010, 1.0E+011, 1.0E+012,
+                                      1.0E+013, 1.0E+014, 1.0E+015, 1.0E+016
+                                    };
+
+      static const std::size_t pow10_size = sizeof(pow10) / sizeof(double);
+
+      namespace numeric
+      {
+         namespace constant
+         {
+            static const double e       =  2.71828182845904523536028747135266249775724709369996;
+            static const double pi      =  3.14159265358979323846264338327950288419716939937510;
+            static const double pi_2    =  1.57079632679489661923132169163975144209858469968755;
+            static const double pi_4    =  0.78539816339744830961566084581987572104929234984378;
+            static const double pi_180  =  0.01745329251994329576923690768488612713442871888542;
+            static const double _1_pi   =  0.31830988618379067153776752674502872406891929148091;
+            static const double _2_pi   =  0.63661977236758134307553505349005744813783858296183;
+            static const double _180_pi = 57.29577951308232087679815481410517033240547246656443;
+            static const double log2    =  0.69314718055994530941723212145817656807550013436026;
+            static const double sqrt2   =  1.41421356237309504880168872420969807856967187537695;
+         }
+
+         namespace details
+         {
+            struct unknown_type_tag { unknown_type_tag() {} };
+            struct real_type_tag    { real_type_tag   () {} };
+            struct complex_type_tag { complex_type_tag() {} };
+            struct int_type_tag     { int_type_tag    () {} };
+
+            template <typename T>
+            struct number_type
+            {
+               typedef unknown_type_tag type;
+               number_type() {}
+            };
+
+            #define exprtk_register_real_type_tag(T)             \
+            template<> struct number_type<T>                     \
+            { typedef real_type_tag type; number_type() {} };    \
+
+            #define exprtk_register_complex_type_tag(T)          \
+            template<> struct number_type<std::complex<T> >      \
+            { typedef complex_type_tag type; number_type() {} }; \
+
+            #define exprtk_register_int_type_tag(T)              \
+            template<> struct number_type<T>                     \
+            { typedef int_type_tag type; number_type() {} };     \
+
+            exprtk_register_real_type_tag(double     )
+            exprtk_register_real_type_tag(long double)
+            exprtk_register_real_type_tag(float      )
+
+            exprtk_register_complex_type_tag(double     )
+            exprtk_register_complex_type_tag(long double)
+            exprtk_register_complex_type_tag(float      )
+
+            exprtk_register_int_type_tag(short         )
+            exprtk_register_int_type_tag(int           )
+            exprtk_register_int_type_tag(_int64_t      )
+            exprtk_register_int_type_tag(unsigned short)
+            exprtk_register_int_type_tag(unsigned int  )
+            exprtk_register_int_type_tag(_uint64_t     )
+
+            #undef exprtk_register_real_type_tag
+            #undef exprtk_register_int_type_tag
+
+            template <typename T>
+            struct epsilon_type
+            {
+               static inline T value()
+               {
+                  const T epsilon = T(0.0000000001);
+                  return epsilon;
+               }
+            };
+
+            template <>
+            struct epsilon_type <float>
+            {
+               static inline float value()
+               {
+                  const float epsilon = float(0.000001f);
+                  return epsilon;
+               }
+            };
+
+            template <>
+            struct epsilon_type <long double>
+            {
+               static inline long double value()
+               {
+                  const long double epsilon = (long double)(0.000000000001);
+                  return epsilon;
+               }
+            };
+
+            template <typename T>
+            inline bool is_nan_impl(const T v, real_type_tag)
+            {
+               return std::not_equal_to<T>()(v,v);
+            }
+
+            template <typename T>
+            inline int to_int32_impl(const T v, real_type_tag)
+            {
+               return static_cast<int>(v);
+            }
+
+            template <typename T>
+            inline _int64_t to_int64_impl(const T v, real_type_tag)
+            {
+               return static_cast<_int64_t>(v);
+            }
+
+            template <typename T>
+            inline bool is_true_impl(const T v)
+            {
+               return std::not_equal_to<T>()(T(0),v);
+            }
+
+            template <typename T>
+            inline bool is_false_impl(const T v)
+            {
+               return std::equal_to<T>()(T(0),v);
+            }
+
+            template <typename T>
+            inline T abs_impl(const T v, real_type_tag)
+            {
+               return ((v < T(0)) ? -v : v);
+            }
+
+            template <typename T>
+            inline T min_impl(const T v0, const T v1, real_type_tag)
+            {
+               return std::min<T>(v0,v1);
+            }
+
+            template <typename T>
+            inline T max_impl(const T v0, const T v1, real_type_tag)
+            {
+               return std::max<T>(v0,v1);
+            }
+
+            template <typename T>
+            inline T equal_impl(const T v0, const T v1, real_type_tag)
+            {
+               const T epsilon = epsilon_type<T>::value();
+               return (abs_impl(v0 - v1,real_type_tag()) <= (std::max(T(1),std::max(abs_impl(v0,real_type_tag()),abs_impl(v1,real_type_tag()))) * epsilon)) ? T(1) : T(0);
+            }
+
+            inline float equal_impl(const float v0, const float v1, real_type_tag)
+            {
+               const float epsilon = epsilon_type<float>::value();
+               return (abs_impl(v0 - v1,real_type_tag()) <= (std::max(1.0f,std::max(abs_impl(v0,real_type_tag()),abs_impl(v1,real_type_tag()))) * epsilon)) ? 1.0f : 0.0f;
+            }
+
+            template <typename T>
+            inline T equal_impl(const T v0, const T v1, int_type_tag)
+            {
+               return (v0 == v1) ? 1 : 0;
+            }
+
+            template <typename T>
+            inline T expm1_impl(const T v, real_type_tag)
+            {
+               // return std::expm1<T>(v);
+               if (abs_impl(v,real_type_tag()) < T(0.00001))
+                  return v + (T(0.5) * v * v);
+               else
+                  return std::exp(v) - T(1);
+            }
+
+            template <typename T>
+            inline T expm1_impl(const T v, int_type_tag)
+            {
+               return T(std::exp<double>(v)) - T(1);
+            }
+
+            template <typename T>
+            inline T nequal_impl(const T v0, const T v1, real_type_tag)
+            {
+               typedef real_type_tag rtg;
+               const T epsilon = epsilon_type<T>::value();
+               return (abs_impl(v0 - v1,rtg()) > (std::max(T(1),std::max(abs_impl(v0,rtg()),abs_impl(v1,rtg()))) * epsilon)) ? T(1) : T(0);
+            }
+
+            inline float nequal_impl(const float v0, const float v1, real_type_tag)
+            {
+               typedef real_type_tag rtg;
+               const float epsilon = epsilon_type<float>::value();
+               return (abs_impl(v0 - v1,rtg()) > (std::max(1.0f,std::max(abs_impl(v0,rtg()),abs_impl(v1,rtg()))) * epsilon)) ? 1.0f : 0.0f;
+            }
+
+            template <typename T>
+            inline T nequal_impl(const T v0, const T v1, int_type_tag)
+            {
+               return (v0 != v1) ? 1 : 0;
+            }
+
+            template <typename T>
+            inline T modulus_impl(const T v0, const T v1, real_type_tag)
+            {
+               return std::fmod(v0,v1);
+            }
+
+            template <typename T>
+            inline T modulus_impl(const T v0, const T v1, int_type_tag)
+            {
+               return v0 % v1;
+            }
+
+            template <typename T>
+            inline T pow_impl(const T v0, const T v1, real_type_tag)
+            {
+               return std::pow(v0,v1);
+            }
+
+            template <typename T>
+            inline T pow_impl(const T v0, const T v1, int_type_tag)
+            {
+               return std::pow(static_cast<double>(v0),static_cast<double>(v1));
+            }
+
+            template <typename T>
+            inline T logn_impl(const T v0, const T v1, real_type_tag)
+            {
+               return std::log(v0) / std::log(v1);
+            }
+
+            template <typename T>
+            inline T logn_impl(const T v0, const T v1, int_type_tag)
+            {
+               return static_cast<T>(logn_impl<double>(static_cast<double>(v0),static_cast<double>(v1),real_type_tag()));
+            }
+
+            template <typename T>
+            inline T log1p_impl(const T v, real_type_tag)
+            {
+               if (v > T(-1))
+               {
+                  if (abs_impl(v,real_type_tag()) > T(0.0001))
+                  {
+                     return std::log(T(1) + v);
+                  }
+                  else
+                     return (T(-0.5) * v + T(1)) * v;
+               }
+               else
+                  return std::numeric_limits<T>::quiet_NaN();
+            }
+
+            template <typename T>
+            inline T log1p_impl(const T v, int_type_tag)
+            {
+               if (v > T(-1))
+               {
+                  return std::log(T(1) + v);
+               }
+               else
+                  return std::numeric_limits<T>::quiet_NaN();
+            }
+
+            template <typename T>
+            inline T root_impl(const T v0, const T v1, real_type_tag)
+            {
+               if (v1 < T(0))
+                  return std::numeric_limits<T>::quiet_NaN();
+
+               const std::size_t n = static_cast<std::size_t>(v1);
+
+               if ((v0 < T(0)) && (0 == (n % 2)))
+                  return std::numeric_limits<T>::quiet_NaN();
+
+               return std::pow(v0, T(1) / n);
+            }
+
+            template <typename T>
+            inline T root_impl(const T v0, const T v1, int_type_tag)
+            {
+               return root_impl<double>(static_cast<double>(v0),static_cast<double>(v1),real_type_tag());
+            }
+
+            template <typename T>
+            inline T round_impl(const T v, real_type_tag)
+            {
+               return ((v < T(0)) ? std::ceil(v - T(0.5)) : std::floor(v + T(0.5)));
+            }
+
+            template <typename T>
+            inline T roundn_impl(const T v0, const T v1, real_type_tag)
+            {
+               const int index = std::max<int>(0, std::min<int>(pow10_size - 1, (int)std::floor(v1)));
+               const T p10 = T(pow10[index]);
+
+               if (v0 < T(0))
+                  return T(std::ceil ((v0 * p10) - T(0.5)) / p10);
+               else
+                  return T(std::floor((v0 * p10) + T(0.5)) / p10);
+            }
+
+            template <typename T>
+            inline T roundn_impl(const T v0, const T, int_type_tag)
+            {
+               return v0;
+            }
+
+            template <typename T>
+            inline T hypot_impl(const T v0, const T v1, real_type_tag)
+            {
+               return std::sqrt((v0 * v0) + (v1 * v1));
+            }
+
+            template <typename T>
+            inline T hypot_impl(const T v0, const T v1, int_type_tag)
+            {
+               return static_cast<T>(std::sqrt(static_cast<double>((v0 * v0) + (v1 * v1))));
+            }
+
+            template <typename T>
+            inline T atan2_impl(const T v0, const T v1, real_type_tag)
+            {
+               return std::atan2(v0,v1);
+            }
+
+            template <typename T>
+            inline T atan2_impl(const T, const T, int_type_tag)
+            {
+               return 0;
+            }
+
+            template <typename T>
+            inline T shr_impl(const T v0, const T v1, real_type_tag)
+            {
+               return v0 * (T(1) / std::pow(T(2),static_cast<T>(static_cast<int>(v1))));
+            }
+
+            template <typename T>
+            inline T shr_impl(const T v0, const T v1, int_type_tag)
+            {
+               return v0 >> v1;
+            }
+
+            template <typename T>
+            inline T shl_impl(const T v0, const T v1, real_type_tag)
+            {
+               return v0 * std::pow(T(2),static_cast<T>(static_cast<int>(v1)));
+            }
+
+            template <typename T>
+            inline T shl_impl(const T v0, const T v1, int_type_tag)
+            {
+               return v0 << v1;
+            }
+
+            template <typename T>
+            inline T sgn_impl(const T v, real_type_tag)
+            {
+                    if (v > T(0)) return T(+1);
+               else if (v < T(0)) return T(-1);
+               else               return T( 0);
+            }
+
+            template <typename T>
+            inline T sgn_impl(const T v, int_type_tag)
+            {
+                    if (v > T(0)) return T(+1);
+               else if (v < T(0)) return T(-1);
+               else               return T( 0);
+            }
+
+            template <typename T>
+            inline T and_impl(const T v0, const T v1, real_type_tag)
+            {
+               return (is_true_impl(v0) && is_true_impl(v1)) ? T(1) : T(0);
+            }
+
+            template <typename T>
+            inline T and_impl(const T v0, const T v1, int_type_tag)
+            {
+               return v0 && v1;
+            }
+
+            template <typename T>
+            inline T nand_impl(const T v0, const T v1, real_type_tag)
+            {
+               return (is_false_impl(v0) || is_false_impl(v1)) ? T(1) : T(0);
+            }
+
+            template <typename T>
+            inline T nand_impl(const T v0, const T v1, int_type_tag)
+            {
+               return !(v0 && v1);
+            }
+
+            template <typename T>
+            inline T or_impl(const T v0, const T v1, real_type_tag)
+            {
+               return (is_true_impl(v0) || is_true_impl(v1)) ? T(1) : T(0);
+            }
+
+            template <typename T>
+            inline T or_impl(const T v0, const T v1, int_type_tag)
+            {
+               return (v0 || v1);
+            }
+
+            template <typename T>
+            inline T nor_impl(const T v0, const T v1, real_type_tag)
+            {
+               return (is_false_impl(v0) && is_false_impl(v1)) ? T(1) : T(0);
+            }
+
+            template <typename T>
+            inline T nor_impl(const T v0, const T v1, int_type_tag)
+            {
+               return !(v0 || v1);
+            }
+
+            template <typename T>
+            inline T xor_impl(const T v0, const T v1, real_type_tag)
+            {
+               return (is_false_impl(v0) != is_false_impl(v1)) ? T(1) : T(0);
+            }
+
+            template <typename T>
+            inline T xor_impl(const T v0, const T v1, int_type_tag)
+            {
+               return v0 ^ v1;
+            }
+
+            template <typename T>
+            inline T xnor_impl(const T v0, const T v1, real_type_tag)
+            {
+               const bool v0_true = is_true_impl(v0);
+               const bool v1_true = is_true_impl(v1);
+
+               if ((v0_true &&  v1_true) || (!v0_true && !v1_true))
+                  return T(1);
+               else
+                  return T(0);
+            }
+
+            template <typename T>
+            inline T xnor_impl(const T v0, const T v1, int_type_tag)
+            {
+               const bool v0_true = is_true_impl(v0);
+               const bool v1_true = is_true_impl(v1);
+
+               if ((v0_true &&  v1_true) || (!v0_true && !v1_true))
+                  return T(1);
+               else
+                  return T(0);
+            }
+
+            #if (defined(_MSC_VER) && (_MSC_VER >= 1900)) || !defined(_MSC_VER)
+            #define exprtk_define_erf(TT,impl)           \
+            inline TT erf_impl(TT v) { return impl(v); } \
+
+            exprtk_define_erf(      float,::erff)
+            exprtk_define_erf(     double,::erf )
+            exprtk_define_erf(long double,::erfl)
+            #undef exprtk_define_erf
+            #endif
+
+            template <typename T>
+            inline T erf_impl(T v, real_type_tag)
+            {
+               #if defined(_MSC_VER) && (_MSC_VER < 1900)
+               // Credits: Abramowitz & Stegun Equations 7.1.25-28
+               static const T c[] = {
+                                      T( 1.26551223), T(1.00002368),
+                                      T( 0.37409196), T(0.09678418),
+                                      T(-0.18628806), T(0.27886807),
+                                      T(-1.13520398), T(1.48851587),
+                                      T(-0.82215223), T(0.17087277)
+                                    };
+
+               const T t = T(1) / (T(1) + T(0.5) * abs_impl(v,real_type_tag()));
+
+               T result = T(1) - t * std::exp((-v * v) -
+                                      c[0] + t * (c[1] + t *
+                                     (c[2] + t * (c[3] + t *
+                                     (c[4] + t * (c[5] + t *
+                                     (c[6] + t * (c[7] + t *
+                                     (c[8] + t * (c[9]))))))))));
+
+               return (v >= T(0)) ? result : -result;
+               #else
+               return erf_impl(v);
+               #endif
+            }
+
+            template <typename T>
+            inline T erf_impl(T v, int_type_tag)
+            {
+               return erf_impl(static_cast<double>(v),real_type_tag());
+            }
+
+            #if (defined(_MSC_VER) && (_MSC_VER >= 1900)) || !defined(_MSC_VER)
+            #define exprtk_define_erfc(TT,impl)           \
+            inline TT erfc_impl(TT v) { return impl(v); } \
+
+            exprtk_define_erfc(      float,::erfcf)
+            exprtk_define_erfc(     double,::erfc )
+            exprtk_define_erfc(long double,::erfcl)
+            #undef exprtk_define_erfc
+            #endif
+
+            template <typename T>
+            inline T erfc_impl(T v, real_type_tag)
+            {
+               #if defined(_MSC_VER) && (_MSC_VER < 1900)
+               return T(1) - erf_impl(v,real_type_tag());
+               #else
+               return erfc_impl(v);
+               #endif
+            }
+
+            template <typename T>
+            inline T erfc_impl(T v, int_type_tag)
+            {
+               return erfc_impl(static_cast<double>(v),real_type_tag());
+            }
+
+            template <typename T>
+            inline T ncdf_impl(T v, real_type_tag)
+            {
+               T cnd = T(0.5) * (T(1) + erf_impl(
+                                           abs_impl(v,real_type_tag()) /
+                                           T(numeric::constant::sqrt2),real_type_tag()));
+               return  (v < T(0)) ? (T(1) - cnd) : cnd;
+            }
+
+            template <typename T>
+            inline T ncdf_impl(T v, int_type_tag)
+            {
+               return ncdf_impl(static_cast<double>(v),real_type_tag());
+            }
+
+            template <typename T>
+            inline T sinc_impl(T v, real_type_tag)
+            {
+               if (std::abs(v) >= std::numeric_limits<T>::epsilon())
+                   return(std::sin(v) / v);
+               else
+                  return T(1);
+            }
+
+            template <typename T>
+            inline T sinc_impl(T v, int_type_tag)
+            {
+               return sinc_impl(static_cast<double>(v),real_type_tag());
+            }
+
+            template <typename T> inline T  acos_impl(const T v, real_type_tag) { return std::acos (v); }
+            template <typename T> inline T acosh_impl(const T v, real_type_tag) { return std::log(v + std::sqrt((v * v) - T(1))); }
+            template <typename T> inline T  asin_impl(const T v, real_type_tag) { return std::asin (v); }
+            template <typename T> inline T asinh_impl(const T v, real_type_tag) { return std::log(v + std::sqrt((v * v) + T(1))); }
+            template <typename T> inline T  atan_impl(const T v, real_type_tag) { return std::atan (v); }
+            template <typename T> inline T atanh_impl(const T v, real_type_tag) { return (std::log(T(1) + v) - std::log(T(1) - v)) / T(2); }
+            template <typename T> inline T  ceil_impl(const T v, real_type_tag) { return std::ceil (v); }
+            template <typename T> inline T   cos_impl(const T v, real_type_tag) { return std::cos  (v); }
+            template <typename T> inline T  cosh_impl(const T v, real_type_tag) { return std::cosh (v); }
+            template <typename T> inline T   exp_impl(const T v, real_type_tag) { return std::exp  (v); }
+            template <typename T> inline T floor_impl(const T v, real_type_tag) { return std::floor(v); }
+            template <typename T> inline T   log_impl(const T v, real_type_tag) { return std::log  (v); }
+            template <typename T> inline T log10_impl(const T v, real_type_tag) { return std::log10(v); }
+            template <typename T> inline T  log2_impl(const T v, real_type_tag) { return std::log(v)/T(numeric::constant::log2); }
+            template <typename T> inline T   neg_impl(const T v, real_type_tag) { return -v;            }
+            template <typename T> inline T   pos_impl(const T v, real_type_tag) { return +v;            }
+            template <typename T> inline T   sin_impl(const T v, real_type_tag) { return std::sin  (v); }
+            template <typename T> inline T  sinh_impl(const T v, real_type_tag) { return std::sinh (v); }
+            template <typename T> inline T  sqrt_impl(const T v, real_type_tag) { return std::sqrt (v); }
+            template <typename T> inline T   tan_impl(const T v, real_type_tag) { return std::tan  (v); }
+            template <typename T> inline T  tanh_impl(const T v, real_type_tag) { return std::tanh (v); }
+            template <typename T> inline T   cot_impl(const T v, real_type_tag) { return T(1) / std::tan(v); }
+            template <typename T> inline T   sec_impl(const T v, real_type_tag) { return T(1) / std::cos(v); }
+            template <typename T> inline T   csc_impl(const T v, real_type_tag) { return T(1) / std::sin(v); }
+            template <typename T> inline T   r2d_impl(const T v, real_type_tag) { return (v * T(numeric::constant::_180_pi)); }
+            template <typename T> inline T   d2r_impl(const T v, real_type_tag) { return (v * T(numeric::constant::pi_180));  }
+            template <typename T> inline T   d2g_impl(const T v, real_type_tag) { return (v * T(20.0/9.0)); }
+            template <typename T> inline T   g2d_impl(const T v, real_type_tag) { return (v * T(9.0/20.0)); }
+            template <typename T> inline T  notl_impl(const T v, real_type_tag) { return (std::not_equal_to<T>()(T(0),v) ? T(0) : T(1)); }
+            template <typename T> inline T  frac_impl(const T v, real_type_tag) { return (v - static_cast<long long>(v)); }
+            template <typename T> inline T trunc_impl(const T v, real_type_tag) { return T(static_cast<long long>(v));    }
+
+            template <typename T> inline T const_pi_impl(real_type_tag) { return T(numeric::constant::pi); }
+            template <typename T> inline T const_e_impl (real_type_tag) { return T(numeric::constant::e);  }
+
+            template <typename T> inline T   abs_impl(const T v, int_type_tag) { return ((v >= T(0)) ? v : -v); }
+            template <typename T> inline T   exp_impl(const T v, int_type_tag) { return std::exp  (v); }
+            template <typename T> inline T   log_impl(const T v, int_type_tag) { return std::log  (v); }
+            template <typename T> inline T log10_impl(const T v, int_type_tag) { return std::log10(v); }
+            template <typename T> inline T  log2_impl(const T v, int_type_tag) { return std::log(v)/T(numeric::constant::log2); }
+            template <typename T> inline T   neg_impl(const T v, int_type_tag) { return -v;            }
+            template <typename T> inline T   pos_impl(const T v, int_type_tag) { return +v;            }
+            template <typename T> inline T  ceil_impl(const T v, int_type_tag) { return v;             }
+            template <typename T> inline T floor_impl(const T v, int_type_tag) { return v;             }
+            template <typename T> inline T round_impl(const T v, int_type_tag) { return v;             }
+            template <typename T> inline T  notl_impl(const T v, int_type_tag) { return !v;            }
+            template <typename T> inline T  sqrt_impl(const T v, int_type_tag) { return std::sqrt (v); }
+            template <typename T> inline T  frac_impl(const T  , int_type_tag) { return T(0);          }
+            template <typename T> inline T trunc_impl(const T v, int_type_tag) { return v;             }
+            template <typename T> inline T  acos_impl(const T  , int_type_tag) { return std::numeric_limits<T>::quiet_NaN(); }
+            template <typename T> inline T acosh_impl(const T  , int_type_tag) { return std::numeric_limits<T>::quiet_NaN(); }
+            template <typename T> inline T  asin_impl(const T  , int_type_tag) { return std::numeric_limits<T>::quiet_NaN(); }
+            template <typename T> inline T asinh_impl(const T  , int_type_tag) { return std::numeric_limits<T>::quiet_NaN(); }
+            template <typename T> inline T  atan_impl(const T  , int_type_tag) { return std::numeric_limits<T>::quiet_NaN(); }
+            template <typename T> inline T atanh_impl(const T  , int_type_tag) { return std::numeric_limits<T>::quiet_NaN(); }
+            template <typename T> inline T   cos_impl(const T  , int_type_tag) { return std::numeric_limits<T>::quiet_NaN(); }
+            template <typename T> inline T  cosh_impl(const T  , int_type_tag) { return std::numeric_limits<T>::quiet_NaN(); }
+            template <typename T> inline T   sin_impl(const T  , int_type_tag) { return std::numeric_limits<T>::quiet_NaN(); }
+            template <typename T> inline T  sinh_impl(const T  , int_type_tag) { return std::numeric_limits<T>::quiet_NaN(); }
+            template <typename T> inline T   tan_impl(const T  , int_type_tag) { return std::numeric_limits<T>::quiet_NaN(); }
+            template <typename T> inline T  tanh_impl(const T  , int_type_tag) { return std::numeric_limits<T>::quiet_NaN(); }
+            template <typename T> inline T   cot_impl(const T  , int_type_tag) { return std::numeric_limits<T>::quiet_NaN(); }
+            template <typename T> inline T   sec_impl(const T  , int_type_tag) { return std::numeric_limits<T>::quiet_NaN(); }
+            template <typename T> inline T   csc_impl(const T  , int_type_tag) { return std::numeric_limits<T>::quiet_NaN(); }
+
+            template <typename T>
+            inline bool is_integer_impl(const T& v, real_type_tag)
+            {
+               return std::equal_to<T>()(T(0),std::fmod(v,T(1)));
+            }
+
+            template <typename T>
+            inline bool is_integer_impl(const T&, int_type_tag)
+            {
+               return true;
+            }
+         }
+
+         template <typename Type>
+         struct numeric_info { enum { length = 0, size = 32, bound_length = 0, min_exp = 0, max_exp = 0 }; };
+
+         template<> struct numeric_info<int>         { enum { length = 10, size = 16, bound_length = 9}; };
+         template<> struct numeric_info<float>       { enum { min_exp =  -38, max_exp =  +38}; };
+         template<> struct numeric_info<double>      { enum { min_exp = -308, max_exp = +308}; };
+         template<> struct numeric_info<long double> { enum { min_exp = -308, max_exp = +308}; };
+
+         template <typename T>
+         inline int to_int32(const T v)
+         {
+            const typename details::number_type<T>::type num_type;
+            return to_int32_impl(v, num_type);
+         }
+
+         template <typename T>
+         inline _int64_t to_int64(const T v)
+         {
+            const typename details::number_type<T>::type num_type;
+            return to_int64_impl(v, num_type);
+         }
+
+         template <typename T>
+         inline bool is_nan(const T v)
+         {
+            const typename details::number_type<T>::type num_type;
+            return is_nan_impl(v, num_type);
+         }
+
+         template <typename T>
+         inline T min(const T v0, const T v1)
+         {
+            const typename details::number_type<T>::type num_type;
+            return min_impl(v0, v1, num_type);
+         }
+
+         template <typename T>
+         inline T max(const T v0, const T v1)
+         {
+            const typename details::number_type<T>::type num_type;
+            return max_impl(v0, v1, num_type);
+         }
+
+         template <typename T>
+         inline T equal(const T v0, const T v1)
+         {
+            const typename details::number_type<T>::type num_type;
+            return equal_impl(v0, v1, num_type);
+         }
+
+         template <typename T>
+         inline T nequal(const T v0, const T v1)
+         {
+            const typename details::number_type<T>::type num_type;
+            return nequal_impl(v0, v1, num_type);
+         }
+
+         template <typename T>
+         inline T modulus(const T v0, const T v1)
+         {
+            const typename details::number_type<T>::type num_type;
+            return modulus_impl(v0, v1, num_type);
+         }
+
+         template <typename T>
+         inline T pow(const T v0, const T v1)
+         {
+            const typename details::number_type<T>::type num_type;
+            return pow_impl(v0, v1, num_type);
+         }
+
+         template <typename T>
+         inline T logn(const T v0, const T v1)
+         {
+            const typename details::number_type<T>::type num_type;
+            return logn_impl(v0, v1, num_type);
+         }
+
+         template <typename T>
+         inline T root(const T v0, const T v1)
+         {
+            const typename details::number_type<T>::type num_type;
+            return root_impl(v0, v1, num_type);
+         }
+
+         template <typename T>
+         inline T roundn(const T v0, const T v1)
+         {
+            const typename details::number_type<T>::type num_type;
+            return roundn_impl(v0, v1, num_type);
+         }
+
+         template <typename T>
+         inline T hypot(const T v0, const T v1)
+         {
+            const typename details::number_type<T>::type num_type;
+            return hypot_impl(v0, v1, num_type);
+         }
+
+         template <typename T>
+         inline T atan2(const T v0, const T v1)
+         {
+            const typename details::number_type<T>::type num_type;
+            return atan2_impl(v0, v1, num_type);
+         }
+
+         template <typename T>
+         inline T shr(const T v0, const T v1)
+         {
+            const typename details::number_type<T>::type num_type;
+            return shr_impl(v0, v1, num_type);
+         }
+
+         template <typename T>
+         inline T shl(const T v0, const T v1)
+         {
+            const typename details::number_type<T>::type num_type;
+            return shl_impl(v0, v1, num_type);
+         }
+
+         template <typename T>
+         inline T and_opr(const T v0, const T v1)
+         {
+            const typename details::number_type<T>::type num_type;
+            return and_impl(v0, v1, num_type);
+         }
+
+         template <typename T>
+         inline T nand_opr(const T v0, const T v1)
+         {
+            const typename details::number_type<T>::type num_type;
+            return nand_impl(v0, v1, num_type);
+         }
+
+         template <typename T>
+         inline T or_opr(const T v0, const T v1)
+         {
+            const typename details::number_type<T>::type num_type;
+            return or_impl(v0, v1, num_type);
+         }
+
+         template <typename T>
+         inline T nor_opr(const T v0, const T v1)
+         {
+            const typename details::number_type<T>::type num_type;
+            return nor_impl(v0, v1, num_type);
+         }
+
+         template <typename T>
+         inline T xor_opr(const T v0, const T v1)
+         {
+            const typename details::number_type<T>::type num_type;
+            return xor_impl(v0, v1, num_type);
+         }
+
+         template <typename T>
+         inline T xnor_opr(const T v0, const T v1)
+         {
+            const typename details::number_type<T>::type num_type;
+            return xnor_impl(v0, v1, num_type);
+         }
+
+         template <typename T>
+         inline bool is_integer(const T v)
+         {
+            const typename details::number_type<T>::type num_type;
+            return is_integer_impl(v, num_type);
+         }
+
+         template <typename T, unsigned int N>
+         struct fast_exp
+         {
+            static inline T result(T v)
+            {
+               unsigned int k = N;
+               T l = T(1);
+
+               while (k)
+               {
+                  if (k & 1)
+                  {
+                     l *= v;
+                     --k;
+                  }
+
+                  v *= v;
+                  k >>= 1;
+               }
+
+               return l;
+            }
+         };
+
+         template <typename T> struct fast_exp<T,10> { static inline T result(T v) { T v_5 = fast_exp<T,5>::result(v); return v_5 * v_5; } };
+         template <typename T> struct fast_exp<T, 9> { static inline T result(T v) { return fast_exp<T,8>::result(v) * v; } };
+         template <typename T> struct fast_exp<T, 8> { static inline T result(T v) { T v_4 = fast_exp<T,4>::result(v); return v_4 * v_4; } };
+         template <typename T> struct fast_exp<T, 7> { static inline T result(T v) { return fast_exp<T,6>::result(v) * v; } };
+         template <typename T> struct fast_exp<T, 6> { static inline T result(T v) { T v_3 = fast_exp<T,3>::result(v); return v_3 * v_3; } };
+         template <typename T> struct fast_exp<T, 5> { static inline T result(T v) { return fast_exp<T,4>::result(v) * v; } };
+         template <typename T> struct fast_exp<T, 4> { static inline T result(T v) { T v_2 = v * v; return v_2 * v_2; } };
+         template <typename T> struct fast_exp<T, 3> { static inline T result(T v) { return v * v * v; } };
+         template <typename T> struct fast_exp<T, 2> { static inline T result(T v) { return v * v;     } };
+         template <typename T> struct fast_exp<T, 1> { static inline T result(T v) { return v;         } };
+         template <typename T> struct fast_exp<T, 0> { static inline T result(T  ) { return T(1);      } };
+
+         #define exprtk_define_unary_function(FunctionName)        \
+         template <typename T>                                     \
+         inline T FunctionName (const T v)                         \
+         {                                                         \
+            const typename details::number_type<T>::type num_type; \
+            return  FunctionName##_impl(v,num_type);               \
+         }                                                         \
+
+         exprtk_define_unary_function(abs  )
+         exprtk_define_unary_function(acos )
+         exprtk_define_unary_function(acosh)
+         exprtk_define_unary_function(asin )
+         exprtk_define_unary_function(asinh)
+         exprtk_define_unary_function(atan )
+         exprtk_define_unary_function(atanh)
+         exprtk_define_unary_function(ceil )
+         exprtk_define_unary_function(cos  )
+         exprtk_define_unary_function(cosh )
+         exprtk_define_unary_function(exp  )
+         exprtk_define_unary_function(expm1)
+         exprtk_define_unary_function(floor)
+         exprtk_define_unary_function(log  )
+         exprtk_define_unary_function(log10)
+         exprtk_define_unary_function(log2 )
+         exprtk_define_unary_function(log1p)
+         exprtk_define_unary_function(neg  )
+         exprtk_define_unary_function(pos  )
+         exprtk_define_unary_function(round)
+         exprtk_define_unary_function(sin  )
+         exprtk_define_unary_function(sinc )
+         exprtk_define_unary_function(sinh )
+         exprtk_define_unary_function(sqrt )
+         exprtk_define_unary_function(tan  )
+         exprtk_define_unary_function(tanh )
+         exprtk_define_unary_function(cot  )
+         exprtk_define_unary_function(sec  )
+         exprtk_define_unary_function(csc  )
+         exprtk_define_unary_function(r2d  )
+         exprtk_define_unary_function(d2r  )
+         exprtk_define_unary_function(d2g  )
+         exprtk_define_unary_function(g2d  )
+         exprtk_define_unary_function(notl )
+         exprtk_define_unary_function(sgn  )
+         exprtk_define_unary_function(erf  )
+         exprtk_define_unary_function(erfc )
+         exprtk_define_unary_function(ncdf )
+         exprtk_define_unary_function(frac )
+         exprtk_define_unary_function(trunc)
+         #undef exprtk_define_unary_function
+      }
+
+      template <typename T>
+      inline T compute_pow10(T d, const int exponent)
+      {
+         static const double fract10[] =
+         {
+           0.0,
+           1.0E+001, 1.0E+002, 1.0E+003, 1.0E+004, 1.0E+005, 1.0E+006, 1.0E+007, 1.0E+008, 1.0E+009, 1.0E+010,
+           1.0E+011, 1.0E+012, 1.0E+013, 1.0E+014, 1.0E+015, 1.0E+016, 1.0E+017, 1.0E+018, 1.0E+019, 1.0E+020,
+           1.0E+021, 1.0E+022, 1.0E+023, 1.0E+024, 1.0E+025, 1.0E+026, 1.0E+027, 1.0E+028, 1.0E+029, 1.0E+030,
+           1.0E+031, 1.0E+032, 1.0E+033, 1.0E+034, 1.0E+035, 1.0E+036, 1.0E+037, 1.0E+038, 1.0E+039, 1.0E+040,
+           1.0E+041, 1.0E+042, 1.0E+043, 1.0E+044, 1.0E+045, 1.0E+046, 1.0E+047, 1.0E+048, 1.0E+049, 1.0E+050,
+           1.0E+051, 1.0E+052, 1.0E+053, 1.0E+054, 1.0E+055, 1.0E+056, 1.0E+057, 1.0E+058, 1.0E+059, 1.0E+060,
+           1.0E+061, 1.0E+062, 1.0E+063, 1.0E+064, 1.0E+065, 1.0E+066, 1.0E+067, 1.0E+068, 1.0E+069, 1.0E+070,
+           1.0E+071, 1.0E+072, 1.0E+073, 1.0E+074, 1.0E+075, 1.0E+076, 1.0E+077, 1.0E+078, 1.0E+079, 1.0E+080,
+           1.0E+081, 1.0E+082, 1.0E+083, 1.0E+084, 1.0E+085, 1.0E+086, 1.0E+087, 1.0E+088, 1.0E+089, 1.0E+090,
+           1.0E+091, 1.0E+092, 1.0E+093, 1.0E+094, 1.0E+095, 1.0E+096, 1.0E+097, 1.0E+098, 1.0E+099, 1.0E+100,
+           1.0E+101, 1.0E+102, 1.0E+103, 1.0E+104, 1.0E+105, 1.0E+106, 1.0E+107, 1.0E+108, 1.0E+109, 1.0E+110,
+           1.0E+111, 1.0E+112, 1.0E+113, 1.0E+114, 1.0E+115, 1.0E+116, 1.0E+117, 1.0E+118, 1.0E+119, 1.0E+120,
+           1.0E+121, 1.0E+122, 1.0E+123, 1.0E+124, 1.0E+125, 1.0E+126, 1.0E+127, 1.0E+128, 1.0E+129, 1.0E+130,
+           1.0E+131, 1.0E+132, 1.0E+133, 1.0E+134, 1.0E+135, 1.0E+136, 1.0E+137, 1.0E+138, 1.0E+139, 1.0E+140,
+           1.0E+141, 1.0E+142, 1.0E+143, 1.0E+144, 1.0E+145, 1.0E+146, 1.0E+147, 1.0E+148, 1.0E+149, 1.0E+150,
+           1.0E+151, 1.0E+152, 1.0E+153, 1.0E+154, 1.0E+155, 1.0E+156, 1.0E+157, 1.0E+158, 1.0E+159, 1.0E+160,
+           1.0E+161, 1.0E+162, 1.0E+163, 1.0E+164, 1.0E+165, 1.0E+166, 1.0E+167, 1.0E+168, 1.0E+169, 1.0E+170,
+           1.0E+171, 1.0E+172, 1.0E+173, 1.0E+174, 1.0E+175, 1.0E+176, 1.0E+177, 1.0E+178, 1.0E+179, 1.0E+180,
+           1.0E+181, 1.0E+182, 1.0E+183, 1.0E+184, 1.0E+185, 1.0E+186, 1.0E+187, 1.0E+188, 1.0E+189, 1.0E+190,
+           1.0E+191, 1.0E+192, 1.0E+193, 1.0E+194, 1.0E+195, 1.0E+196, 1.0E+197, 1.0E+198, 1.0E+199, 1.0E+200,
+           1.0E+201, 1.0E+202, 1.0E+203, 1.0E+204, 1.0E+205, 1.0E+206, 1.0E+207, 1.0E+208, 1.0E+209, 1.0E+210,
+           1.0E+211, 1.0E+212, 1.0E+213, 1.0E+214, 1.0E+215, 1.0E+216, 1.0E+217, 1.0E+218, 1.0E+219, 1.0E+220,
+           1.0E+221, 1.0E+222, 1.0E+223, 1.0E+224, 1.0E+225, 1.0E+226, 1.0E+227, 1.0E+228, 1.0E+229, 1.0E+230,
+           1.0E+231, 1.0E+232, 1.0E+233, 1.0E+234, 1.0E+235, 1.0E+236, 1.0E+237, 1.0E+238, 1.0E+239, 1.0E+240,
+           1.0E+241, 1.0E+242, 1.0E+243, 1.0E+244, 1.0E+245, 1.0E+246, 1.0E+247, 1.0E+248, 1.0E+249, 1.0E+250,
+           1.0E+251, 1.0E+252, 1.0E+253, 1.0E+254, 1.0E+255, 1.0E+256, 1.0E+257, 1.0E+258, 1.0E+259, 1.0E+260,
+           1.0E+261, 1.0E+262, 1.0E+263, 1.0E+264, 1.0E+265, 1.0E+266, 1.0E+267, 1.0E+268, 1.0E+269, 1.0E+270,
+           1.0E+271, 1.0E+272, 1.0E+273, 1.0E+274, 1.0E+275, 1.0E+276, 1.0E+277, 1.0E+278, 1.0E+279, 1.0E+280,
+           1.0E+281, 1.0E+282, 1.0E+283, 1.0E+284, 1.0E+285, 1.0E+286, 1.0E+287, 1.0E+288, 1.0E+289, 1.0E+290,
+           1.0E+291, 1.0E+292, 1.0E+293, 1.0E+294, 1.0E+295, 1.0E+296, 1.0E+297, 1.0E+298, 1.0E+299, 1.0E+300,
+           1.0E+301, 1.0E+302, 1.0E+303, 1.0E+304, 1.0E+305, 1.0E+306, 1.0E+307, 1.0E+308
+         };
+
+         static const int fract10_size = static_cast<int>(sizeof(fract10) / sizeof(double));
+
+         const int e = std::abs(exponent);
+
+         if (exponent >= std::numeric_limits<T>::min_exponent10)
+         {
+            if (e < fract10_size)
+            {
+               if (exponent > 0)
+                  return T(d * fract10[e]);
+               else
+                  return T(d / fract10[e]);
+            }
+            else
+               return T(d * std::pow(10.0, 10.0 * exponent));
+         }
+         else
+         {
+                     d /= T(fract10[           -std::numeric_limits<T>::min_exponent10]);
+            return T(d /    fract10[-exponent + std::numeric_limits<T>::min_exponent10]);
+         }
+      }
+
+      template <typename Iterator, typename T>
+      inline bool string_to_type_converter_impl_ref(Iterator& itr, const Iterator end, T& result)
+      {
+         if (itr == end)
+            return false;
+
+         const bool negative = ('-' == (*itr));
+
+         if (negative || ('+' == (*itr)))
+         {
+            if (end == ++itr)
+               return false;
+         }
+
+         static const uchar_t zero = static_cast<uchar_t>('0');
+
+         while ((end != itr) && (zero == (*itr))) ++itr;
+
+         bool return_result = true;
+         unsigned int digit = 0;
+         const std::size_t length  = static_cast<std::size_t>(std::distance(itr,end));
+
+         if (length <= 4)
+         {
+            exprtk_disable_fallthrough_begin
+            switch (length)
+            {
+               #ifdef exprtk_use_lut
+
+               #define exprtk_process_digit                          \
+               if ((digit = details::digit_table[(int)*itr++]) < 10) \
+                  result = result * 10 + (digit);                    \
+               else                                                  \
+               {                                                     \
+                  return_result = false;                             \
+                  break;                                             \
+               }                                                     \
+
+               #else
+
+               #define exprtk_process_digit         \
+               if ((digit = (*itr++ - zero)) < 10)  \
+                  result = result * T(10) + digit;  \
+               else                                 \
+               {                                    \
+                  return_result = false;            \
+                  break;                            \
+               }                                    \
+
+               #endif
+
+               case  4 : exprtk_process_digit
+               case  3 : exprtk_process_digit
+               case  2 : exprtk_process_digit
+               case  1 : if ((digit = (*itr - zero))>= 10) { digit = 0; return_result = false; }
+
+               #undef exprtk_process_digit
+            }
+            exprtk_disable_fallthrough_end
+         }
+         else
+            return_result = false;
+
+         if (length && return_result)
+         {
+            result = result * 10 + static_cast<T>(digit);
+            ++itr;
+         }
+
+         result = negative ? -result : result;
+         return return_result;
+      }
+
+      template <typename Iterator, typename T>
+      static inline bool parse_nan(Iterator& itr, const Iterator end, T& t)
+      {
+         typedef typename std::iterator_traits<Iterator>::value_type type;
+
+         static const std::size_t nan_length = 3;
+
+         if (std::distance(itr,end) != static_cast<int>(nan_length))
+            return false;
+
+         if (static_cast<type>('n') == (*itr))
+         {
+            if (
+                 (static_cast<type>('a') != *(itr + 1)) ||
+                 (static_cast<type>('n') != *(itr + 2))
+               )
+            {
+               return false;
+            }
+         }
+         else if (
+                   (static_cast<type>('A') != *(itr + 1)) ||
+                   (static_cast<type>('N') != *(itr + 2))
+                 )
+         {
+            return false;
+         }
+
+         t = std::numeric_limits<T>::quiet_NaN();
+
+         return true;
+      }
+
+      template <typename Iterator, typename T>
+      static inline bool parse_inf(Iterator& itr, const Iterator end, T& t, bool negative)
+      {
+         static const char_t inf_uc[] = "INFINITY";
+         static const char_t inf_lc[] = "infinity";
+         static const std::size_t inf_length = 8;
+
+         const std::size_t length = static_cast<std::size_t>(std::distance(itr,end));
+
+         if ((3 != length) && (inf_length != length))
+            return false;
+
+         char_cptr inf_itr = ('i' == (*itr)) ? inf_lc : inf_uc;
+
+         while (end != itr)
+         {
+            if (*inf_itr == static_cast<char>(*itr))
+            {
+               ++itr;
+               ++inf_itr;
+               continue;
+            }
+            else
+               return false;
+         }
+
+         if (negative)
+            t = -std::numeric_limits<T>::infinity();
+         else
+            t =  std::numeric_limits<T>::infinity();
+
+         return true;
+      }
+
+      template <typename Iterator, typename T>
+      inline bool string_to_real(Iterator& itr_external, const Iterator end, T& t, numeric::details::real_type_tag)
+      {
+         if (end == itr_external) return false;
+
+         Iterator itr = itr_external;
+
+         T d = T(0);
+
+         const bool negative = ('-' == (*itr));
+
+         if (negative || '+' == (*itr))
+         {
+            if (end == ++itr)
+               return false;
+         }
+
+         bool instate = false;
+
+         static const char_t zero = static_cast<uchar_t>('0');
+
+         #define parse_digit_1(d)          \
+         if ((digit = (*itr - zero)) < 10) \
+            { d = d * T(10) + digit; }     \
+         else                              \
+            { break; }                     \
+         if (end == ++itr) break;          \
+
+         #define parse_digit_2(d)          \
+         if ((digit = (*itr - zero)) < 10) \
+            { d = d * T(10) + digit; }     \
+         else { break; }                   \
+            ++itr;                         \
+
+         if ('.' != (*itr))
+         {
+            const Iterator curr = itr;
+
+            while ((end != itr) && (zero == (*itr))) ++itr;
+
+            unsigned int digit;
+
+            while (end != itr)
+            {
+               // Note: For 'physical' superscalar architectures it
+               // is advised that the following loop be: 4xPD1 and 1xPD2
+               #ifdef exprtk_enable_superscalar
+               parse_digit_1(d)
+               parse_digit_1(d)
+               #endif
+               parse_digit_1(d)
+               parse_digit_1(d)
+               parse_digit_2(d)
+            }
+
+            if (curr != itr) instate = true;
+         }
+
+         int exponent = 0;
+
+         if (end != itr)
+         {
+            if ('.' == (*itr))
+            {
+               const Iterator curr = ++itr;
+               unsigned int digit;
+               T tmp_d = T(0);
+
+               while (end != itr)
+               {
+                  #ifdef exprtk_enable_superscalar
+                  parse_digit_1(tmp_d)
+                  parse_digit_1(tmp_d)
+                  parse_digit_1(tmp_d)
+                  #endif
+                  parse_digit_1(tmp_d)
+                  parse_digit_1(tmp_d)
+                  parse_digit_2(tmp_d)
+               }
+
+               if (curr != itr)
+               {
+                  instate = true;
+                  d += compute_pow10(tmp_d,static_cast<int>(-std::distance(curr,itr)));
+               }
+
+               #undef parse_digit_1
+               #undef parse_digit_2
+            }
+
+            if (end != itr)
+            {
+               typename std::iterator_traits<Iterator>::value_type c = (*itr);
+
+               if (('e' == c) || ('E' == c))
+               {
+                  int exp = 0;
+
+                  if (!details::string_to_type_converter_impl_ref(++itr, end, exp))
+                  {
+                     if (end == itr)
+                        return false;
+                     else
+                        c = (*itr);
+                  }
+
+                  exponent += exp;
+               }
+
+               if (end != itr)
+               {
+                  if (('f' == c) || ('F' == c) || ('l' == c) || ('L' == c))
+                     ++itr;
+                  else if ('#' == c)
+                  {
+                     if (end == ++itr)
+                        return false;
+                     else if (('I' <= (*itr)) && ((*itr) <= 'n'))
+                     {
+                        if (('i' == (*itr)) || ('I' == (*itr)))
+                        {
+                           return parse_inf(itr, end, t, negative);
+                        }
+                        else if (('n' == (*itr)) || ('N' == (*itr)))
+                        {
+                           return parse_nan(itr, end, t);
+                        }
+                        else
+                           return false;
+                     }
+                     else
+                        return false;
+                  }
+                  else if (('I' <= (*itr)) && ((*itr) <= 'n'))
+                  {
+                     if (('i' == (*itr)) || ('I' == (*itr)))
+                     {
+                        return parse_inf(itr, end, t, negative);
+                     }
+                     else if (('n' == (*itr)) || ('N' == (*itr)))
+                     {
+                        return parse_nan(itr, end, t);
+                     }
+                     else
+                        return false;
+                  }
+                  else
+                     return false;
+               }
+            }
+         }
+
+         if ((end != itr) || (!instate))
+            return false;
+         else if (exponent)
+            d = compute_pow10(d,exponent);
+
+         t = static_cast<T>((negative) ? -d : d);
+         return true;
+      }
+
+      template <typename T>
+      inline bool string_to_real(const std::string& s, T& t)
+      {
+         const typename numeric::details::number_type<T>::type num_type;
+
+         char_cptr begin = s.data();
+         char_cptr end   = s.data() + s.size();
+
+         return string_to_real(begin, end, t, num_type);
+      }
+
+      template <typename T>
+      struct functor_t
+      {
+         /*
+            Note: The following definitions for Type, may require tweaking
+                  based on the compiler and target architecture. The benchmark
+                  should provide enough information to make the right choice.
+         */
+         //typedef T Type;
+         //typedef const T Type;
+         typedef const T& Type;
+         typedef       T& RefType;
+         typedef T (*qfunc_t)(Type t0, Type t1, Type t2, Type t3);
+         typedef T (*tfunc_t)(Type t0, Type t1, Type t2);
+         typedef T (*bfunc_t)(Type t0, Type t1);
+         typedef T (*ufunc_t)(Type t0);
+      };
+
+   } // namespace details
+
+   namespace lexer
+   {
+      struct token
+      {
+         enum token_type
+         {
+            e_none        =   0, e_error       =   1, e_err_symbol  =   2,
+            e_err_number  =   3, e_err_string  =   4, e_err_sfunc   =   5,
+            e_eof         =   6, e_number      =   7, e_symbol      =   8,
+            e_string      =   9, e_assign      =  10, e_addass      =  11,
+            e_subass      =  12, e_mulass      =  13, e_divass      =  14,
+            e_modass      =  15, e_shr         =  16, e_shl         =  17,
+            e_lte         =  18, e_ne          =  19, e_gte         =  20,
+            e_swap        =  21, e_lt          = '<', e_gt          = '>',
+            e_eq          = '=', e_rbracket    = ')', e_lbracket    = '(',
+            e_rsqrbracket = ']', e_lsqrbracket = '[', e_rcrlbracket = '}',
+            e_lcrlbracket = '{', e_comma       = ',', e_add         = '+',
+            e_sub         = '-', e_div         = '/', e_mul         = '*',
+            e_mod         = '%', e_pow         = '^', e_colon       = ':',
+            e_ternary     = '?'
+         };
+
+         token()
+         : type(e_none),
+           value(""),
+           position(std::numeric_limits<std::size_t>::max())
+         {}
+
+         void clear()
+         {
+            type     = e_none;
+            value    = "";
+            position = std::numeric_limits<std::size_t>::max();
+         }
+
+         template <typename Iterator>
+         inline token& set_operator(const token_type tt,
+                                    const Iterator begin, const Iterator end,
+                                    const Iterator base_begin = Iterator(0))
+         {
+            type = tt;
+            value.assign(begin,end);
+            if (base_begin)
+               position = static_cast<std::size_t>(std::distance(base_begin,begin));
+            return (*this);
+         }
+
+         template <typename Iterator>
+         inline token& set_symbol(const Iterator begin, const Iterator end, const Iterator base_begin = Iterator(0))
+         {
+            type = e_symbol;
+            value.assign(begin,end);
+            if (base_begin)
+               position = static_cast<std::size_t>(std::distance(base_begin,begin));
+            return (*this);
+         }
+
+         template <typename Iterator>
+         inline token& set_numeric(const Iterator begin, const Iterator end, const Iterator base_begin = Iterator(0))
+         {
+            type = e_number;
+            value.assign(begin,end);
+            if (base_begin)
+               position = static_cast<std::size_t>(std::distance(base_begin,begin));
+            return (*this);
+         }
+
+         template <typename Iterator>
+         inline token& set_string(const Iterator begin, const Iterator end, const Iterator base_begin = Iterator(0))
+         {
+            type = e_string;
+            value.assign(begin,end);
+            if (base_begin)
+               position = static_cast<std::size_t>(std::distance(base_begin,begin));
+            return (*this);
+         }
+
+         inline token& set_string(const std::string& s, const std::size_t p)
+         {
+            type     = e_string;
+            value    = s;
+            position = p;
+            return (*this);
+         }
+
+         template <typename Iterator>
+         inline token& set_error(const token_type et,
+                                 const Iterator begin, const Iterator end,
+                                 const Iterator base_begin = Iterator(0))
+         {
+            if (
+                 (e_error      == et) ||
+                 (e_err_symbol == et) ||
+                 (e_err_number == et) ||
+                 (e_err_string == et) ||
+                 (e_err_sfunc  == et)
+               )
+            {
+               type = et;
+            }
+            else
+               type = e_error;
+
+            value.assign(begin,end);
+
+            if (base_begin)
+               position = static_cast<std::size_t>(std::distance(base_begin,begin));
+
+            return (*this);
+         }
+
+         static inline std::string to_str(token_type t)
+         {
+            switch (t)
+            {
+               case e_none        : return "NONE";
+               case e_error       : return "ERROR";
+               case e_err_symbol  : return "ERROR_SYMBOL";
+               case e_err_number  : return "ERROR_NUMBER";
+               case e_err_string  : return "ERROR_STRING";
+               case e_eof         : return "EOF";
+               case e_number      : return "NUMBER";
+               case e_symbol      : return "SYMBOL";
+               case e_string      : return "STRING";
+               case e_assign      : return ":=";
+               case e_addass      : return "+=";
+               case e_subass      : return "-=";
+               case e_mulass      : return "*=";
+               case e_divass      : return "/=";
+               case e_modass      : return "%=";
+               case e_shr         : return ">>";
+               case e_shl         : return "<<";
+               case e_lte         : return "<=";
+               case e_ne          : return "!=";
+               case e_gte         : return ">=";
+               case e_lt          : return "<";
+               case e_gt          : return ">";
+               case e_eq          : return "=";
+               case e_rbracket    : return ")";
+               case e_lbracket    : return "(";
+               case e_rsqrbracket : return "]";
+               case e_lsqrbracket : return "[";
+               case e_rcrlbracket : return "}";
+               case e_lcrlbracket : return "{";
+               case e_comma       : return ",";
+               case e_add         : return "+";
+               case e_sub         : return "-";
+               case e_div         : return "/";
+               case e_mul         : return "*";
+               case e_mod         : return "%";
+               case e_pow         : return "^";
+               case e_colon       : return ":";
+               case e_ternary     : return "?";
+               case e_swap        : return "<=>";
+               default            : return "UNKNOWN";
+            }
+         }
+
+         inline bool is_error() const
+         {
+            return (
+                     (e_error      == type) ||
+                     (e_err_symbol == type) ||
+                     (e_err_number == type) ||
+                     (e_err_string == type) ||
+                     (e_err_sfunc  == type)
+                   );
+         }
+
+         token_type type;
+         std::string value;
+         std::size_t position;
+      };
+
+      class generator
+      {
+      public:
+
+         typedef token token_t;
+         typedef std::vector<token_t> token_list_t;
+         typedef std::vector<token_t>::iterator token_list_itr_t;
+         typedef details::char_t char_t;
+
+         generator()
+         : base_itr_(0),
+           s_itr_   (0),
+           s_end_   (0)
+         {
+            clear();
+         }
+
+         inline void clear()
+         {
+            base_itr_ = 0;
+            s_itr_    = 0;
+            s_end_    = 0;
+            token_list_.clear();
+            token_itr_ = token_list_.end();
+            store_token_itr_ = token_list_.end();
+         }
+
+         inline bool process(const std::string& str)
+         {
+            base_itr_ = str.data();
+            s_itr_    = str.data();
+            s_end_    = str.data() + str.size();
+
+            eof_token_.set_operator(token_t::e_eof,s_end_,s_end_,base_itr_);
+            token_list_.clear();
+
+            while (!is_end(s_itr_))
+            {
+               scan_token();
+
+               if (!token_list_.empty() && token_list_.back().is_error())
+                  return false;
+            }
+
+            return true;
+         }
+
+         inline bool empty() const
+         {
+            return token_list_.empty();
+         }
+
+         inline std::size_t size() const
+         {
+            return token_list_.size();
+         }
+
+         inline void begin()
+         {
+            token_itr_ = token_list_.begin();
+            store_token_itr_ = token_list_.begin();
+         }
+
+         inline void store()
+         {
+            store_token_itr_ = token_itr_;
+         }
+
+         inline void restore()
+         {
+            token_itr_ = store_token_itr_;
+         }
+
+         inline token_t& next_token()
+         {
+            if (token_list_.end() != token_itr_)
+            {
+               return *token_itr_++;
+            }
+            else
+               return eof_token_;
+         }
+
+         inline token_t& peek_next_token()
+         {
+            if (token_list_.end() != token_itr_)
+            {
+               return *token_itr_;
+            }
+            else
+               return eof_token_;
+         }
+
+         inline token_t& operator[](const std::size_t& index)
+         {
+            if (index < token_list_.size())
+               return token_list_[index];
+            else
+               return eof_token_;
+         }
+
+         inline token_t operator[](const std::size_t& index) const
+         {
+            if (index < token_list_.size())
+               return token_list_[index];
+            else
+               return eof_token_;
+         }
+
+         inline bool finished() const
+         {
+            return (token_list_.end() == token_itr_);
+         }
+
+         inline void insert_front(token_t::token_type tk_type)
+         {
+            if (
+                 !token_list_.empty() &&
+                 (token_list_.end() != token_itr_)
+               )
+            {
+               token_t t = *token_itr_;
+
+               t.type     = tk_type;
+               token_itr_ = token_list_.insert(token_itr_,t);
+            }
+         }
+
+         inline std::string substr(const std::size_t& begin, const std::size_t& end)
+         {
+            const details::char_cptr begin_itr = ((base_itr_ + begin) < s_end_) ? (base_itr_ + begin) : s_end_;
+            const details::char_cptr end_itr   = ((base_itr_ +   end) < s_end_) ? (base_itr_ +   end) : s_end_;
+
+            return std::string(begin_itr,end_itr);
+         }
+
+         inline std::string remaining() const
+         {
+            if (finished())
+               return "";
+            else if (token_list_.begin() != token_itr_)
+               return std::string(base_itr_ + (token_itr_ - 1)->position, s_end_);
+            else
+               return std::string(base_itr_ + token_itr_->position, s_end_);
+         }
+
+      private:
+
+         inline bool is_end(details::char_cptr itr)
+         {
+            return (s_end_ == itr);
+         }
+
+         inline bool is_comment_start(details::char_cptr itr)
+         {
+            #ifndef exprtk_disable_comments
+            const char_t c0 = *(itr + 0);
+            const char_t c1 = *(itr + 1);
+
+            if ('#' == c0)
+               return true;
+            else if (!is_end(itr + 1))
+            {
+               if (('/' == c0) && ('/' == c1)) return true;
+               if (('/' == c0) && ('*' == c1)) return true;
+            }
+            #endif
+            return false;
+         }
+
+         inline void skip_whitespace()
+         {
+            while (!is_end(s_itr_) && details::is_whitespace(*s_itr_))
+            {
+               ++s_itr_;
+            }
+         }
+
+         inline void skip_comments()
+         {
+            #ifndef exprtk_disable_comments
+            // The following comment styles are supported:
+            // 1. // .... \n
+            // 2. #  .... \n
+            // 3. /* .... */
+            struct test
+            {
+               static inline bool comment_start(const char_t c0, const char_t c1, int& mode, int& incr)
+               {
+                  mode = 0;
+                       if ('#' == c0)    { mode = 1; incr = 1; }
+                  else if ('/' == c0)
+                  {
+                          if ('/' == c1) { mode = 1; incr = 2; }
+                     else if ('*' == c1) { mode = 2; incr = 2; }
+                  }
+                  return (0 != mode);
+               }
+
+               static inline bool comment_end(const char_t c0, const char_t c1, int& mode)
+               {
+                  if (
+                       ((1 == mode) && ('\n' == c0)) ||
+                       ((2 == mode) && ( '*' == c0) && ('/' == c1))
+                     )
+                  {
+                     mode = 0;
+                     return true;
+                  }
+                  else
+                     return false;
+               }
+            };
+
+            int mode      = 0;
+            int increment = 0;
+
+            if (is_end(s_itr_))
+               return;
+            else if (!test::comment_start(*s_itr_, *(s_itr_ + 1), mode, increment))
+               return;
+
+            details::char_cptr cmt_start = s_itr_;
+
+            s_itr_ += increment;
+
+            while (!is_end(s_itr_))
+            {
+               if ((1 == mode) && test::comment_end(*s_itr_, 0, mode))
+               {
+                  ++s_itr_;
+                  return;
+               }
+
+               if ((2 == mode))
+               {
+                  if (!is_end((s_itr_ + 1)) && test::comment_end(*s_itr_, *(s_itr_ + 1), mode))
+                  {
+                     s_itr_ += 2;
+                     return;
+                  }
+               }
+
+                ++s_itr_;
+            }
+
+            if (2 == mode)
+            {
+               token_t t;
+               t.set_error(token::e_error, cmt_start, cmt_start + mode, base_itr_);
+               token_list_.push_back(t);
+            }
+            #endif
+         }
+
+         inline void scan_token()
+         {
+            if (details::is_whitespace(*s_itr_))
+            {
+               skip_whitespace();
+               return;
+            }
+            else if (is_comment_start(s_itr_))
+            {
+               skip_comments();
+               return;
+            }
+            else if (details::is_operator_char(*s_itr_))
+            {
+               scan_operator();
+               return;
+            }
+            else if (details::is_letter(*s_itr_))
+            {
+               scan_symbol();
+               return;
+            }
+            else if (details::is_digit((*s_itr_)) || ('.' == (*s_itr_)))
+            {
+               scan_number();
+               return;
+            }
+            else if ('$' == (*s_itr_))
+            {
+               scan_special_function();
+               return;
+            }
+            #ifndef exprtk_disable_string_capabilities
+            else if ('\'' == (*s_itr_))
+            {
+               scan_string();
+               return;
+            }
+            #endif
+            else if ('~' == (*s_itr_))
+            {
+               token_t t;
+               t.set_symbol(s_itr_, s_itr_ + 1, base_itr_);
+               token_list_.push_back(t);
+               ++s_itr_;
+               return;
+            }
+            else
+            {
+               token_t t;
+               t.set_error(token::e_error, s_itr_, s_itr_ + 2, base_itr_);
+               token_list_.push_back(t);
+               ++s_itr_;
+            }
+         }
+
+         inline void scan_operator()
+         {
+            token_t t;
+
+            const char_t c0 = s_itr_[0];
+
+            if (!is_end(s_itr_ + 1))
+            {
+               const char_t c1 = s_itr_[1];
+
+               if (!is_end(s_itr_ + 2))
+               {
+                  const char_t c2 = s_itr_[2];
+
+                  if ((c0 == '<') && (c1 == '=') && (c2 == '>'))
+                  {
+                     t.set_operator(token_t::e_swap, s_itr_, s_itr_ + 3, base_itr_);
+                     token_list_.push_back(t);
+                     s_itr_ += 3;
+                     return;
+                  }
+               }
+
+               token_t::token_type ttype = token_t::e_none;
+
+                    if ((c0 == '<') && (c1 == '=')) ttype = token_t::e_lte;
+               else if ((c0 == '>') && (c1 == '=')) ttype = token_t::e_gte;
+               else if ((c0 == '<') && (c1 == '>')) ttype = token_t::e_ne;
+               else if ((c0 == '!') && (c1 == '=')) ttype = token_t::e_ne;
+               else if ((c0 == '=') && (c1 == '=')) ttype = token_t::e_eq;
+               else if ((c0 == ':') && (c1 == '=')) ttype = token_t::e_assign;
+               else if ((c0 == '<') && (c1 == '<')) ttype = token_t::e_shl;
+               else if ((c0 == '>') && (c1 == '>')) ttype = token_t::e_shr;
+               else if ((c0 == '+') && (c1 == '=')) ttype = token_t::e_addass;
+               else if ((c0 == '-') && (c1 == '=')) ttype = token_t::e_subass;
+               else if ((c0 == '*') && (c1 == '=')) ttype = token_t::e_mulass;
+               else if ((c0 == '/') && (c1 == '=')) ttype = token_t::e_divass;
+               else if ((c0 == '%') && (c1 == '=')) ttype = token_t::e_modass;
+
+               if (token_t::e_none != ttype)
+               {
+                  t.set_operator(ttype, s_itr_, s_itr_ + 2, base_itr_);
+                  token_list_.push_back(t);
+                  s_itr_ += 2;
+                  return;
+               }
+            }
+
+            if ('<' == c0)
+               t.set_operator(token_t::e_lt , s_itr_, s_itr_ + 1, base_itr_);
+            else if ('>' == c0)
+               t.set_operator(token_t::e_gt , s_itr_, s_itr_ + 1, base_itr_);
+            else if (';' == c0)
+               t.set_operator(token_t::e_eof, s_itr_, s_itr_ + 1, base_itr_);
+            else if ('&' == c0)
+               t.set_symbol(s_itr_, s_itr_ + 1, base_itr_);
+            else if ('|' == c0)
+               t.set_symbol(s_itr_, s_itr_ + 1, base_itr_);
+            else
+               t.set_operator(token_t::token_type(c0), s_itr_, s_itr_ + 1, base_itr_);
+
+            token_list_.push_back(t);
+            ++s_itr_;
+         }
+
+         inline void scan_symbol()
+         {
+            details::char_cptr initial_itr = s_itr_;
+
+            while (!is_end(s_itr_))
+            {
+               if (!details::is_letter_or_digit(*s_itr_) && ('_' != (*s_itr_)))
+               {
+                  if ('.' != (*s_itr_))
+                     break;
+                  /*
+                     Permit symbols that contain a 'dot'
+                     Allowed   : abc.xyz, a123.xyz, abc.123, abc_.xyz a123_.xyz abc._123
+                     Disallowed: .abc, abc.<white-space>, abc.<eof>, abc.<operator +,-,*,/...>
+                  */
+                  if (
+                       (s_itr_ != initial_itr)                     &&
+                       !is_end(s_itr_ + 1)                         &&
+                       !details::is_letter_or_digit(*(s_itr_ + 1)) &&
+                       ('_' != (*(s_itr_ + 1)))
+                     )
+                     break;
+               }
+
+               ++s_itr_;
+            }
+
+            token_t t;
+            t.set_symbol(initial_itr,s_itr_,base_itr_);
+            token_list_.push_back(t);
+         }
+
+         inline void scan_number()
+         {
+            /*
+               Attempt to match a valid numeric value in one of the following formats:
+               (01) 123456
+               (02) 123456.
+               (03) 123.456
+               (04) 123.456e3
+               (05) 123.456E3
+               (06) 123.456e+3
+               (07) 123.456E+3
+               (08) 123.456e-3
+               (09) 123.456E-3
+               (00) .1234
+               (11) .1234e3
+               (12) .1234E+3
+               (13) .1234e+3
+               (14) .1234E-3
+               (15) .1234e-3
+            */
+
+            details::char_cptr initial_itr = s_itr_;
+            bool dot_found                 = false;
+            bool e_found                   = false;
+            bool post_e_sign_found         = false;
+            bool post_e_digit_found        = false;
+            token_t t;
+
+            while (!is_end(s_itr_))
+            {
+               if ('.' == (*s_itr_))
+               {
+                  if (dot_found)
+                  {
+                     t.set_error(token::e_err_number, initial_itr, s_itr_, base_itr_);
+                     token_list_.push_back(t);
+                     return;
+                  }
+
+                  dot_found = true;
+                  ++s_itr_;
+
+                  continue;
+               }
+               else if ('e' == std::tolower(*s_itr_))
+               {
+                  const char_t& c = *(s_itr_ + 1);
+
+                  if (is_end(s_itr_ + 1))
+                  {
+                     t.set_error(token::e_err_number, initial_itr, s_itr_, base_itr_);
+                     token_list_.push_back(t);
+
+                     return;
+                  }
+                  else if (
+                            ('+' != c) &&
+                            ('-' != c) &&
+                            !details::is_digit(c)
+                          )
+                  {
+                     t.set_error(token::e_err_number, initial_itr, s_itr_, base_itr_);
+                     token_list_.push_back(t);
+
+                     return;
+                  }
+
+                  e_found = true;
+                  ++s_itr_;
+
+                  continue;
+               }
+               else if (e_found && details::is_sign(*s_itr_) && !post_e_digit_found)
+               {
+                  if (post_e_sign_found)
+                  {
+                     t.set_error(token::e_err_number, initial_itr, s_itr_, base_itr_);
+                     token_list_.push_back(t);
+
+                     return;
+                  }
+
+                  post_e_sign_found = true;
+                  ++s_itr_;
+
+                  continue;
+               }
+               else if (e_found && details::is_digit(*s_itr_))
+               {
+                  post_e_digit_found = true;
+                  ++s_itr_;
+
+                  continue;
+               }
+               else if (('.' != (*s_itr_)) && !details::is_digit(*s_itr_))
+                  break;
+               else
+                  ++s_itr_;
+            }
+
+            t.set_numeric(initial_itr, s_itr_, base_itr_);
+            token_list_.push_back(t);
+
+            return;
+         }
+
+         inline void scan_special_function()
+         {
+            details::char_cptr initial_itr = s_itr_;
+            token_t t;
+
+            // $fdd(x,x,x) = at least 11 chars
+            if (std::distance(s_itr_,s_end_) < 11)
+            {
+               t.set_error(token::e_err_sfunc, initial_itr, s_itr_, base_itr_);
+               token_list_.push_back(t);
+
+               return;
+            }
+
+            if (
+                 !(('$' == *s_itr_)                       &&
+                   (details::imatch  ('f',*(s_itr_ + 1))) &&
+                   (details::is_digit(*(s_itr_ + 2)))     &&
+                   (details::is_digit(*(s_itr_ + 3))))
+               )
+            {
+               t.set_error(token::e_err_sfunc, initial_itr, s_itr_, base_itr_);
+               token_list_.push_back(t);
+
+               return;
+            }
+
+            s_itr_ += 4; // $fdd = 4chars
+
+            t.set_symbol(initial_itr, s_itr_, base_itr_);
+            token_list_.push_back(t);
+
+            return;
+         }
+
+         #ifndef exprtk_disable_string_capabilities
+         inline void scan_string()
+         {
+            details::char_cptr initial_itr = s_itr_ + 1;
+            token_t t;
+
+            if (std::distance(s_itr_,s_end_) < 2)
+            {
+               t.set_error(token::e_err_string, s_itr_, s_end_, base_itr_);
+               token_list_.push_back(t);
+               return;
+            }
+
+            ++s_itr_;
+
+            bool escaped_found = false;
+            bool escaped = false;
+
+            while (!is_end(s_itr_))
+            {
+               if (!escaped && ('\\' == *s_itr_))
+               {
+                  escaped_found = true;
+                  escaped = true;
+                  ++s_itr_;
+
+                  continue;
+               }
+               else if (!escaped)
+               {
+                  if ('\'' == *s_itr_)
+                     break;
+               }
+               else if (escaped)
+               {
+                  if (!is_end(s_itr_) && ('0' == *(s_itr_)))
+                  {
+                     /*
+                        Note: The following 'awkward' conditional is
+                              due to various broken msvc compilers.
+                     */
+                     #if defined(_MSC_VER) && (_MSC_VER == 1600)
+                     const bool within_range = !is_end(s_itr_ + 2) &&
+                                               !is_end(s_itr_ + 3) ;
+                     #else
+                     const bool within_range = !is_end(s_itr_ + 1) &&
+                                               !is_end(s_itr_ + 2) &&
+                                               !is_end(s_itr_ + 3) ;
+                     #endif
+
+                     const bool x_seperator  = ('x' == *(s_itr_ + 1)) ||
+                                               ('X' == *(s_itr_ + 1)) ;
+
+                     const bool both_digits  = details::is_hex_digit(*(s_itr_ + 2)) &&
+                                               details::is_hex_digit(*(s_itr_ + 3)) ;
+
+                     if (!within_range || !x_seperator || !both_digits)
+                     {
+                        t.set_error(token::e_err_string, initial_itr, s_itr_, base_itr_);
+                        token_list_.push_back(t);
+
+                        return;
+                     }
+                     else
+                        s_itr_ += 3;
+                  }
+
+                  escaped = false;
+               }
+
+               ++s_itr_;
+            }
+
+            if (is_end(s_itr_))
+            {
+               t.set_error(token::e_err_string, initial_itr, s_itr_, base_itr_);
+               token_list_.push_back(t);
+
+               return;
+            }
+
+            if (!escaped_found)
+               t.set_string(initial_itr, s_itr_, base_itr_);
+            else
+            {
+               std::string parsed_string(initial_itr,s_itr_);
+
+               details::cleanup_escapes(parsed_string);
+
+               t.set_string(
+                    parsed_string,
+                    static_cast<std::size_t>(std::distance(base_itr_,initial_itr)));
+            }
+
+            token_list_.push_back(t);
+            ++s_itr_;
+
+            return;
+         }
+         #endif
+
+      private:
+
+         token_list_t     token_list_;
+         token_list_itr_t token_itr_;
+         token_list_itr_t store_token_itr_;
+         token_t eof_token_;
+         details::char_cptr base_itr_;
+         details::char_cptr s_itr_;
+         details::char_cptr s_end_;
+
+         friend class token_scanner;
+         friend class token_modifier;
+         friend class token_inserter;
+         friend class token_joiner;
+      };
+
+      class helper_interface
+      {
+      public:
+
+         virtual void init()                     {              }
+         virtual void reset()                    {              }
+         virtual bool result()                   { return true; }
+         virtual std::size_t process(generator&) { return 0;    }
+         virtual ~helper_interface()             {              }
+      };
+
+      class token_scanner : public helper_interface
+      {
+      public:
+
+         virtual ~token_scanner()
+         {}
+
+         explicit token_scanner(const std::size_t& stride)
+         : stride_(stride)
+         {
+            if (stride > 4)
+            {
+               throw std::invalid_argument("token_scanner() - Invalid stride value");
+            }
+         }
+
+         inline std::size_t process(generator& g)
+         {
+            if (g.token_list_.size() >= stride_)
+            {
+               for (std::size_t i = 0; i < (g.token_list_.size() - stride_ + 1); ++i)
+               {
+                  token t;
+
+                  switch (stride_)
+                  {
+                     case 1 :
+                              {
+                                 const token& t0 = g.token_list_[i];
+
+                                 if (!operator()(t0))
+                                 {
+                                    return i;
+                                 }
+                              }
+                              break;
+
+                     case 2 :
+                              {
+                                 const token& t0 = g.token_list_[i    ];
+                                 const token& t1 = g.token_list_[i + 1];
+
+                                 if (!operator()(t0, t1))
+                                 {
+                                    return i;
+                                 }
+                              }
+                              break;
+
+                     case 3 :
+                              {
+                                 const token& t0 = g.token_list_[i    ];
+                                 const token& t1 = g.token_list_[i + 1];
+                                 const token& t2 = g.token_list_[i + 2];
+
+                                 if (!operator()(t0, t1, t2))
+                                 {
+                                    return i;
+                                 }
+                              }
+                              break;
+
+                     case 4 :
+                              {
+                                 const token& t0 = g.token_list_[i    ];
+                                 const token& t1 = g.token_list_[i + 1];
+                                 const token& t2 = g.token_list_[i + 2];
+                                 const token& t3 = g.token_list_[i + 3];
+
+                                 if (!operator()(t0, t1, t2, t3))
+                                 {
+                                    return i;
+                                 }
+                              }
+                              break;
+                  }
+               }
+            }
+
+            return (g.token_list_.size() - stride_ + 1);
+         }
+
+         virtual bool operator() (const token&)
+         {
+            return false;
+         }
+
+         virtual bool operator() (const token&, const token&)
+         {
+            return false;
+         }
+
+         virtual bool operator() (const token&, const token&, const token&)
+         {
+            return false;
+         }
+
+         virtual bool operator() (const token&, const token&, const token&, const token&)
+         {
+            return false;
+         }
+
+      private:
+
+         const std::size_t stride_;
+      };
+
+      class token_modifier : public helper_interface
+      {
+      public:
+
+         inline std::size_t process(generator& g)
+         {
+            std::size_t changes = 0;
+
+            for (std::size_t i = 0; i < g.token_list_.size(); ++i)
+            {
+               if (modify(g.token_list_[i])) changes++;
+            }
+
+            return changes;
+         }
+
+         virtual bool modify(token& t) = 0;
+      };
+
+      class token_inserter : public helper_interface
+      {
+      public:
+
+         explicit token_inserter(const std::size_t& stride)
+         : stride_(stride)
+         {
+            if (stride > 5)
+            {
+               throw std::invalid_argument("token_inserter() - Invalid stride value");
+            }
+         }
+
+         inline std::size_t process(generator& g)
+         {
+            if (g.token_list_.empty())
+               return 0;
+            else if (g.token_list_.size() < stride_)
+               return 0;
+
+            std::size_t changes = 0;
+
+            for (std::size_t i = 0; i < (g.token_list_.size() - stride_ + 1); ++i)
+            {
+               int insert_index = -1;
+               token t;
+
+               switch (stride_)
+               {
+                  case 1 : insert_index = insert(g.token_list_[i],t);
+                           break;
+
+                  case 2 : insert_index = insert(g.token_list_[i], g.token_list_[i + 1], t);
+                           break;
+
+                  case 3 : insert_index = insert(g.token_list_[i], g.token_list_[i + 1], g.token_list_[i + 2], t);
+                           break;
+
+                  case 4 : insert_index = insert(g.token_list_[i], g.token_list_[i + 1], g.token_list_[i + 2], g.token_list_[i + 3], t);
+                           break;
+
+                  case 5 : insert_index = insert(g.token_list_[i], g.token_list_[i + 1], g.token_list_[i + 2], g.token_list_[i + 3], g.token_list_[i + 4], t);
+                           break;
+               }
+
+               typedef std::iterator_traits<generator::token_list_t::iterator>::difference_type diff_t;
+
+               if ((insert_index >= 0) && (insert_index <= (static_cast<int>(stride_) + 1)))
+               {
+                  g.token_list_.insert(
+                     g.token_list_.begin() + static_cast<diff_t>(i + static_cast<std::size_t>(insert_index)), t);
+
+                  changes++;
+               }
+            }
+
+            return changes;
+         }
+
+         #define token_inserter_empty_body \
+         {                                 \
+            return -1;                     \
+         }                                 \
+
+         inline virtual int insert(const token&, token&)
+         token_inserter_empty_body
+
+         inline virtual int insert(const token&, const token&, token&)
+         token_inserter_empty_body
+
+         inline virtual int insert(const token&, const token&, const token&, token&)
+         token_inserter_empty_body
+
+         inline virtual int insert(const token&, const token&, const token&, const token&, token&)
+         token_inserter_empty_body
+
+         inline virtual int insert(const token&, const token&, const token&, const token&, const token&, token&)
+         token_inserter_empty_body
+
+         #undef token_inserter_empty_body
+
+      private:
+
+         const std::size_t stride_;
+      };
+
+      class token_joiner : public helper_interface
+      {
+      public:
+
+         explicit token_joiner(const std::size_t& stride)
+         : stride_(stride)
+         {}
+
+         inline std::size_t process(generator& g)
+         {
+            if (g.token_list_.empty())
+               return 0;
+
+            switch (stride_)
+            {
+               case 2  : return process_stride_2(g);
+               case 3  : return process_stride_3(g);
+               default : return 0;
+            }
+         }
+
+         virtual bool join(const token&, const token&, token&)               { return false; }
+         virtual bool join(const token&, const token&, const token&, token&) { return false; }
+
+      private:
+
+         inline std::size_t process_stride_2(generator& g)
+         {
+            typedef std::iterator_traits<generator::token_list_t::iterator>::difference_type diff_t;
+
+            if (g.token_list_.size() < 2)
+               return 0;
+
+            std::size_t changes = 0;
+
+            for (int i = 0;  i < static_cast<int>(g.token_list_.size() - 1); ++i)
+            {
+               token t;
+
+               while (join(g[i], g[i + 1], t))
+               {
+                  g.token_list_[i] = t;
+
+                  g.token_list_.erase(g.token_list_.begin() + static_cast<diff_t>(i + 1));
+
+                  ++changes;
+
+                  if (static_cast<std::size_t>(i + 1) >= g.token_list_.size())
+                     break;
+               }
+            }
+
+            return changes;
+         }
+
+         inline std::size_t process_stride_3(generator& g)
+         {
+            typedef std::iterator_traits<generator::token_list_t::iterator>::difference_type diff_t;
+
+            if (g.token_list_.size() < 3)
+               return 0;
+
+            std::size_t changes = 0;
+
+            for (int i = 0;  i < static_cast<int>(g.token_list_.size() - 2); ++i)
+            {
+               token t;
+
+               while (join(g[i], g[i + 1], g[i + 2], t))
+               {
+                  g.token_list_[i] = t;
+
+                  g.token_list_.erase(g.token_list_.begin() + static_cast<diff_t>(i + 1),
+                                      g.token_list_.begin() + static_cast<diff_t>(i + 3));
+                  ++changes;
+
+                  if (static_cast<std::size_t>(i + 2) >= g.token_list_.size())
+                     break;
+               }
+            }
+
+            return changes;
+         }
+
+         const std::size_t stride_;
+      };
+
+      namespace helper
+      {
+
+         inline void dump(lexer::generator& generator)
+         {
+            for (std::size_t i = 0; i < generator.size(); ++i)
+            {
+               lexer::token t = generator[i];
+               printf("Token[%02d] @ %03d  %6s  -->  '%s'\n",
+                      static_cast<int>(i),
+                      static_cast<int>(t.position),
+                      t.to_str(t.type).c_str(),
+                      t.value.c_str());
+            }
+         }
+
+         class commutative_inserter : public lexer::token_inserter
+         {
+         public:
+
+            using lexer::token_inserter::insert;
+
+            commutative_inserter()
+            : lexer::token_inserter(2)
+            {}
+
+            inline void ignore_symbol(const std::string& symbol)
+            {
+               ignore_set_.insert(symbol);
+            }
+
+            inline int insert(const lexer::token& t0, const lexer::token& t1, lexer::token& new_token)
+            {
+               bool match         = false;
+               new_token.type     = lexer::token::e_mul;
+               new_token.value    = "*";
+               new_token.position = t1.position;
+
+               if (t0.type == lexer::token::e_symbol)
+               {
+                  if (ignore_set_.end() != ignore_set_.find(t0.value))
+                  {
+                     return -1;
+                  }
+                  else if (!t0.value.empty() && ('$' == t0.value[0]))
+                  {
+                     return -1;
+                  }
+               }
+
+               if (t1.type == lexer::token::e_symbol)
+               {
+                  if (ignore_set_.end() != ignore_set_.find(t1.value))
+                  {
+                     return -1;
+                  }
+               }
+                    if ((t0.type == lexer::token::e_number     ) && (t1.type == lexer::token::e_symbol     )) match = true;
+               else if ((t0.type == lexer::token::e_number     ) && (t1.type == lexer::token::e_lbracket   )) match = true;
+               else if ((t0.type == lexer::token::e_number     ) && (t1.type == lexer::token::e_lcrlbracket)) match = true;
+               else if ((t0.type == lexer::token::e_number     ) && (t1.type == lexer::token::e_lsqrbracket)) match = true;
+               else if ((t0.type == lexer::token::e_symbol     ) && (t1.type == lexer::token::e_number     )) match = true;
+               else if ((t0.type == lexer::token::e_rbracket   ) && (t1.type == lexer::token::e_number     )) match = true;
+               else if ((t0.type == lexer::token::e_rcrlbracket) && (t1.type == lexer::token::e_number     )) match = true;
+               else if ((t0.type == lexer::token::e_rsqrbracket) && (t1.type == lexer::token::e_number     )) match = true;
+               else if ((t0.type == lexer::token::e_rbracket   ) && (t1.type == lexer::token::e_symbol     )) match = true;
+               else if ((t0.type == lexer::token::e_rcrlbracket) && (t1.type == lexer::token::e_symbol     )) match = true;
+               else if ((t0.type == lexer::token::e_rsqrbracket) && (t1.type == lexer::token::e_symbol     )) match = true;
+               else if ((t0.type == lexer::token::e_symbol     ) && (t1.type == lexer::token::e_symbol     )) match = true;
+
+               return (match) ? 1 : -1;
+            }
+
+         private:
+
+            std::set<std::string,details::ilesscompare> ignore_set_;
+         };
+
+         class operator_joiner : public token_joiner
+         {
+         public:
+
+            explicit operator_joiner(const std::size_t& stride)
+            : token_joiner(stride)
+            {}
+
+            inline bool join(const lexer::token& t0, const lexer::token& t1, lexer::token& t)
+            {
+               // ': =' --> ':='
+               if ((t0.type == lexer::token::e_colon) && (t1.type == lexer::token::e_eq))
+               {
+                  t.type     = lexer::token::e_assign;
+                  t.value    = ":=";
+                  t.position = t0.position;
+
+                  return true;
+               }
+               // '+ =' --> '+='
+               else if ((t0.type == lexer::token::e_add) && (t1.type == lexer::token::e_eq))
+               {
+                  t.type     = lexer::token::e_addass;
+                  t.value    = "+=";
+                  t.position = t0.position;
+
+                  return true;
+               }
+               // '- =' --> '-='
+               else if ((t0.type == lexer::token::e_sub) && (t1.type == lexer::token::e_eq))
+               {
+                  t.type     = lexer::token::e_subass;
+                  t.value    = "-=";
+                  t.position = t0.position;
+
+                  return true;
+               }
+               // '* =' --> '*='
+               else if ((t0.type == lexer::token::e_mul) && (t1.type == lexer::token::e_eq))
+               {
+                  t.type     = lexer::token::e_mulass;
+                  t.value    = "*=";
+                  t.position = t0.position;
+
+                  return true;
+               }
+               // '/ =' --> '/='
+               else if ((t0.type == lexer::token::e_div) && (t1.type == lexer::token::e_eq))
+               {
+                  t.type     = lexer::token::e_divass;
+                  t.value    = "/=";
+                  t.position = t0.position;
+
+                  return true;
+               }
+               // '% =' --> '%='
+               else if ((t0.type == lexer::token::e_mod) && (t1.type == lexer::token::e_eq))
+               {
+                  t.type     = lexer::token::e_modass;
+                  t.value    = "%=";
+                  t.position = t0.position;
+
+                  return true;
+               }
+               // '> =' --> '>='
+               else if ((t0.type == lexer::token::e_gt) && (t1.type == lexer::token::e_eq))
+               {
+                  t.type     = lexer::token::e_gte;
+                  t.value    = ">=";
+                  t.position = t0.position;
+
+                  return true;
+               }
+               // '< =' --> '<='
+               else if ((t0.type == lexer::token::e_lt) && (t1.type == lexer::token::e_eq))
+               {
+                  t.type     = lexer::token::e_lte;
+                  t.value    = "<=";
+                  t.position = t0.position;
+
+                  return true;
+               }
+               // '= =' --> '=='
+               else if ((t0.type == lexer::token::e_eq) && (t1.type == lexer::token::e_eq))
+               {
+                  t.type     = lexer::token::e_eq;
+                  t.value    = "==";
+                  t.position = t0.position;
+
+                  return true;
+               }
+               // '! =' --> '!='
+               else if ((static_cast<char>(t0.type) == '!') && (t1.type == lexer::token::e_eq))
+               {
+                  t.type     = lexer::token::e_ne;
+                  t.value    = "!=";
+                  t.position = t0.position;
+
+                  return true;
+               }
+               // '< >' --> '<>'
+               else if ((t0.type == lexer::token::e_lt) && (t1.type == lexer::token::e_gt))
+               {
+                  t.type     = lexer::token::e_ne;
+                  t.value    = "<>";
+                  t.position = t0.position;
+
+                  return true;
+               }
+               // '<= >' --> '<=>'
+               else if ((t0.type == lexer::token::e_lte) && (t1.type == lexer::token::e_gt))
+               {
+                  t.type     = lexer::token::e_swap;
+                  t.value    = "<=>";
+                  t.position = t0.position;
+
+                  return true;
+               }
+               // '+ -' --> '-'
+               else if ((t0.type == lexer::token::e_add) && (t1.type == lexer::token::e_sub))
+               {
+                  t.type     = lexer::token::e_sub;
+                  t.value    = "-";
+                  t.position = t0.position;
+
+                  return true;
+               }
+               // '- +' --> '-'
+               else if ((t0.type == lexer::token::e_sub) && (t1.type == lexer::token::e_add))
+               {
+                  t.type     = lexer::token::e_sub;
+                  t.value    = "-";
+                  t.position = t0.position;
+
+                  return true;
+               }
+               // '- -' --> '+'
+               else if ((t0.type == lexer::token::e_sub) && (t1.type == lexer::token::e_sub))
+               {
+                  /*
+                     Note: May need to reconsider this when wanting to implement
+                     pre/postfix decrement operator
+                  */
+                  t.type     = lexer::token::e_add;
+                  t.value    = "+";
+                  t.position = t0.position;
+
+                  return true;
+               }
+               else
+                  return false;
+            }
+
+            inline bool join(const lexer::token& t0, const lexer::token& t1, const lexer::token& t2, lexer::token& t)
+            {
+               // '[ * ]' --> '[*]'
+               if (
+                    (t0.type == lexer::token::e_lsqrbracket) &&
+                    (t1.type == lexer::token::e_mul        ) &&
+                    (t2.type == lexer::token::e_rsqrbracket)
+                  )
+               {
+                  t.type     = lexer::token::e_symbol;
+                  t.value    = "[*]";
+                  t.position = t0.position;
+
+                  return true;
+               }
+               else
+                  return false;
+            }
+         };
+
+         class bracket_checker : public lexer::token_scanner
+         {
+         public:
+
+            using lexer::token_scanner::operator();
+
+            bracket_checker()
+            : token_scanner(1),
+              state_(true)
+            {}
+
+            bool result()
+            {
+               if (!stack_.empty())
+               {
+                  lexer::token t;
+                  t.value      = stack_.top().first;
+                  t.position   = stack_.top().second;
+                  error_token_ = t;
+                  state_       = false;
+
+                  return false;
+               }
+               else
+                  return state_;
+            }
+
+            lexer::token error_token()
+            {
+               return error_token_;
+            }
+
+            void reset()
+            {
+               // Why? because msvc doesn't support swap properly.
+               stack_ = std::stack<std::pair<char,std::size_t> >();
+               state_ = true;
+               error_token_.clear();
+            }
+
+            bool operator() (const lexer::token& t)
+            {
+               if (
+                    !t.value.empty()                       &&
+                    (lexer::token::e_string != t.type)     &&
+                    (lexer::token::e_symbol != t.type)     &&
+                    exprtk::details::is_bracket(t.value[0])
+                  )
+               {
+                  details::char_t c = t.value[0];
+
+                       if (t.type == lexer::token::e_lbracket   ) stack_.push(std::make_pair(')',t.position));
+                  else if (t.type == lexer::token::e_lcrlbracket) stack_.push(std::make_pair('}',t.position));
+                  else if (t.type == lexer::token::e_lsqrbracket) stack_.push(std::make_pair(']',t.position));
+                  else if (exprtk::details::is_right_bracket(c))
+                  {
+                     if (stack_.empty())
+                     {
+                        state_       = false;
+                        error_token_ = t;
+
+                        return false;
+                     }
+                     else if (c != stack_.top().first)
+                     {
+                        state_       = false;
+                        error_token_ = t;
+
+                        return false;
+                     }
+                     else
+                        stack_.pop();
+                  }
+               }
+
+               return true;
+            }
+
+         private:
+
+            bool state_;
+            std::stack<std::pair<char,std::size_t> > stack_;
+            lexer::token error_token_;
+         };
+
+         class numeric_checker : public lexer::token_scanner
+         {
+         public:
+
+            using lexer::token_scanner::operator();
+
+            numeric_checker()
+            : token_scanner (1),
+              current_index_(0)
+            {}
+
+            bool result()
+            {
+               return error_list_.empty();
+            }
+
+            void reset()
+            {
+               error_list_.clear();
+               current_index_ = 0;
+            }
+
+            bool operator() (const lexer::token& t)
+            {
+               if (token::e_number == t.type)
+               {
+                  double v;
+
+                  if (!exprtk::details::string_to_real(t.value,v))
+                  {
+                     error_list_.push_back(current_index_);
+                  }
+               }
+
+               ++current_index_;
+
+               return true;
+            }
+
+            std::size_t error_count() const
+            {
+               return error_list_.size();
+            }
+
+            std::size_t error_index(const std::size_t& i)
+            {
+               if (i < error_list_.size())
+                  return error_list_[i];
+               else
+                  return std::numeric_limits<std::size_t>::max();
+            }
+
+            void clear_errors()
+            {
+               error_list_.clear();
+            }
+
+         private:
+
+            std::size_t current_index_;
+            std::vector<std::size_t> error_list_;
+         };
+
+         class symbol_replacer : public lexer::token_modifier
+         {
+         private:
+
+            typedef std::map<std::string,std::pair<std::string,token::token_type>,details::ilesscompare> replace_map_t;
+
+         public:
+
+            bool remove(const std::string& target_symbol)
+            {
+               const replace_map_t::iterator itr = replace_map_.find(target_symbol);
+
+               if (replace_map_.end() == itr)
+                  return false;
+
+               replace_map_.erase(itr);
+
+               return true;
+            }
+
+            bool add_replace(const std::string& target_symbol,
+                             const std::string& replace_symbol,
+                             const lexer::token::token_type token_type = lexer::token::e_symbol)
+            {
+               const replace_map_t::iterator itr = replace_map_.find(target_symbol);
+
+               if (replace_map_.end() != itr)
+               {
+                  return false;
+               }
+
+               replace_map_[target_symbol] = std::make_pair(replace_symbol,token_type);
+
+               return true;
+            }
+
+            void clear()
+            {
+               replace_map_.clear();
+            }
+
+         private:
+
+            bool modify(lexer::token& t)
+            {
+               if (lexer::token::e_symbol == t.type)
+               {
+                  if (replace_map_.empty())
+                     return false;
+
+                  const replace_map_t::iterator itr = replace_map_.find(t.value);
+
+                  if (replace_map_.end() != itr)
+                  {
+                     t.value = itr->second.first;
+                     t.type  = itr->second.second;
+
+                     return true;
+                  }
+               }
+
+               return false;
+            }
+
+            replace_map_t replace_map_;
+         };
+
+         class sequence_validator : public lexer::token_scanner
+         {
+         private:
+
+            typedef std::pair<lexer::token::token_type,lexer::token::token_type> token_pair_t;
+            typedef std::set<token_pair_t> set_t;
+
+         public:
+
+            using lexer::token_scanner::operator();
+
+            sequence_validator()
+            : lexer::token_scanner(2)
+            {
+               add_invalid(lexer::token::e_number, lexer::token::e_number);
+               add_invalid(lexer::token::e_string, lexer::token::e_string);
+               add_invalid(lexer::token::e_number, lexer::token::e_string);
+               add_invalid(lexer::token::e_string, lexer::token::e_number);
+
+               add_invalid_set1(lexer::token::e_assign );
+               add_invalid_set1(lexer::token::e_shr    );
+               add_invalid_set1(lexer::token::e_shl    );
+               add_invalid_set1(lexer::token::e_lte    );
+               add_invalid_set1(lexer::token::e_ne     );
+               add_invalid_set1(lexer::token::e_gte    );
+               add_invalid_set1(lexer::token::e_lt     );
+               add_invalid_set1(lexer::token::e_gt     );
+               add_invalid_set1(lexer::token::e_eq     );
+               add_invalid_set1(lexer::token::e_comma  );
+               add_invalid_set1(lexer::token::e_add    );
+               add_invalid_set1(lexer::token::e_sub    );
+               add_invalid_set1(lexer::token::e_div    );
+               add_invalid_set1(lexer::token::e_mul    );
+               add_invalid_set1(lexer::token::e_mod    );
+               add_invalid_set1(lexer::token::e_pow    );
+               add_invalid_set1(lexer::token::e_colon  );
+               add_invalid_set1(lexer::token::e_ternary);
+            }
+
+            bool result()
+            {
+               return error_list_.empty();
+            }
+
+            bool operator() (const lexer::token& t0, const lexer::token& t1)
+            {
+               const set_t::value_type p = std::make_pair(t0.type,t1.type);
+
+               if (invalid_bracket_check(t0.type,t1.type))
+               {
+                  error_list_.push_back(std::make_pair(t0,t1));
+               }
+               else if (invalid_comb_.find(p) != invalid_comb_.end())
+               {
+                  error_list_.push_back(std::make_pair(t0,t1));
+               }
+
+               return true;
+            }
+
+            std::size_t error_count() const
+            {
+               return error_list_.size();
+            }
+
+            std::pair<lexer::token,lexer::token> error(const std::size_t index)
+            {
+               if (index < error_list_.size())
+               {
+                  return error_list_[index];
+               }
+               else
+               {
+                  static const lexer::token error_token;
+                  return std::make_pair(error_token,error_token);
+               }
+            }
+
+            void clear_errors()
+            {
+               error_list_.clear();
+            }
+
+         private:
+
+            void add_invalid(lexer::token::token_type base, lexer::token::token_type t)
+            {
+               invalid_comb_.insert(std::make_pair(base,t));
+            }
+
+            void add_invalid_set1(lexer::token::token_type t)
+            {
+               add_invalid(t, lexer::token::e_assign);
+               add_invalid(t, lexer::token::e_shr   );
+               add_invalid(t, lexer::token::e_shl   );
+               add_invalid(t, lexer::token::e_lte   );
+               add_invalid(t, lexer::token::e_ne    );
+               add_invalid(t, lexer::token::e_gte   );
+               add_invalid(t, lexer::token::e_lt    );
+               add_invalid(t, lexer::token::e_gt    );
+               add_invalid(t, lexer::token::e_eq    );
+               add_invalid(t, lexer::token::e_comma );
+               add_invalid(t, lexer::token::e_div   );
+               add_invalid(t, lexer::token::e_mul   );
+               add_invalid(t, lexer::token::e_mod   );
+               add_invalid(t, lexer::token::e_pow   );
+               add_invalid(t, lexer::token::e_colon );
+            }
+
+            bool invalid_bracket_check(lexer::token::token_type base, lexer::token::token_type t)
+            {
+               if (details::is_right_bracket(static_cast<char>(base)))
+               {
+                  switch (t)
+                  {
+                     case lexer::token::e_assign : return (']' != base);
+                     case lexer::token::e_string : return (')' != base);
+                     default                     : return false;
+                  }
+               }
+               else if (details::is_left_bracket(static_cast<char>(base)))
+               {
+                  if (details::is_right_bracket(static_cast<char>(t)))
+                     return false;
+                  else if (details::is_left_bracket(static_cast<char>(t)))
+                     return false;
+                  else
+                  {
+                     switch (t)
+                     {
+                        case lexer::token::e_number  : return false;
+                        case lexer::token::e_symbol  : return false;
+                        case lexer::token::e_string  : return false;
+                        case lexer::token::e_add     : return false;
+                        case lexer::token::e_sub     : return false;
+                        case lexer::token::e_colon   : return false;
+                        case lexer::token::e_ternary : return false;
+                        default                      : return true ;
+                     }
+                  }
+               }
+               else if (details::is_right_bracket(static_cast<char>(t)))
+               {
+                  switch (base)
+                  {
+                     case lexer::token::e_number  : return false;
+                     case lexer::token::e_symbol  : return false;
+                     case lexer::token::e_string  : return false;
+                     case lexer::token::e_eof     : return false;
+                     case lexer::token::e_colon   : return false;
+                     case lexer::token::e_ternary : return false;
+                     default                      : return true ;
+                  }
+               }
+               else if (details::is_left_bracket(static_cast<char>(t)))
+               {
+                  switch (base)
+                  {
+                     case lexer::token::e_rbracket    : return true;
+                     case lexer::token::e_rsqrbracket : return true;
+                     case lexer::token::e_rcrlbracket : return true;
+                     default                          : return false;
+                  }
+               }
+
+               return false;
+            }
+
+            set_t invalid_comb_;
+            std::vector<std::pair<lexer::token,lexer::token> > error_list_;
+         };
+
+         class sequence_validator_3tokens : public lexer::token_scanner
+         {
+         private:
+
+            typedef lexer::token::token_type token_t;
+            typedef std::pair<token_t,std::pair<token_t,token_t> > token_triplet_t;
+            typedef std::set<token_triplet_t> set_t;
+
+         public:
+
+            using lexer::token_scanner::operator();
+
+            sequence_validator_3tokens()
+            : lexer::token_scanner(3)
+            {
+               add_invalid(lexer::token::e_number, lexer::token::e_number, lexer::token::e_number);
+               add_invalid(lexer::token::e_string, lexer::token::e_string, lexer::token::e_string);
+               add_invalid(lexer::token::e_comma , lexer::token::e_comma , lexer::token::e_comma );
+
+               add_invalid(lexer::token::e_add   , lexer::token::e_add   , lexer::token::e_add   );
+               add_invalid(lexer::token::e_sub   , lexer::token::e_sub   , lexer::token::e_sub   );
+               add_invalid(lexer::token::e_div   , lexer::token::e_div   , lexer::token::e_div   );
+               add_invalid(lexer::token::e_mul   , lexer::token::e_mul   , lexer::token::e_mul   );
+               add_invalid(lexer::token::e_mod   , lexer::token::e_mod   , lexer::token::e_mod   );
+               add_invalid(lexer::token::e_pow   , lexer::token::e_pow   , lexer::token::e_pow   );
+
+               add_invalid(lexer::token::e_add   , lexer::token::e_sub   , lexer::token::e_add   );
+               add_invalid(lexer::token::e_sub   , lexer::token::e_add   , lexer::token::e_sub   );
+               add_invalid(lexer::token::e_div   , lexer::token::e_mul   , lexer::token::e_div   );
+               add_invalid(lexer::token::e_mul   , lexer::token::e_div   , lexer::token::e_mul   );
+               add_invalid(lexer::token::e_mod   , lexer::token::e_pow   , lexer::token::e_mod   );
+               add_invalid(lexer::token::e_pow   , lexer::token::e_mod   , lexer::token::e_pow   );
+            }
+
+            bool result()
+            {
+               return error_list_.empty();
+            }
+
+            bool operator() (const lexer::token& t0, const lexer::token& t1, const lexer::token& t2)
+            {
+               const set_t::value_type p = std::make_pair(t0.type,std::make_pair(t1.type,t2.type));
+
+               if (invalid_comb_.find(p) != invalid_comb_.end())
+               {
+                  error_list_.push_back(std::make_pair(t0,t1));
+               }
+
+               return true;
+            }
+
+            std::size_t error_count() const
+            {
+               return error_list_.size();
+            }
+
+            std::pair<lexer::token,lexer::token> error(const std::size_t index)
+            {
+               if (index < error_list_.size())
+               {
+                  return error_list_[index];
+               }
+               else
+               {
+                  static const lexer::token error_token;
+                  return std::make_pair(error_token,error_token);
+               }
+            }
+
+            void clear_errors()
+            {
+               error_list_.clear();
+            }
+
+         private:
+
+            void add_invalid(token_t t0, token_t t1, token_t t2)
+            {
+               invalid_comb_.insert(std::make_pair(t0,std::make_pair(t1,t2)));
+            }
+
+            set_t invalid_comb_;
+            std::vector<std::pair<lexer::token,lexer::token> > error_list_;
+         };
+
+         struct helper_assembly
+         {
+            inline bool register_scanner(lexer::token_scanner* scanner)
+            {
+               if (token_scanner_list.end() != std::find(token_scanner_list.begin(),
+                                                         token_scanner_list.end  (),
+                                                         scanner))
+               {
+                  return false;
+               }
+
+               token_scanner_list.push_back(scanner);
+
+               return true;
+            }
+
+            inline bool register_modifier(lexer::token_modifier* modifier)
+            {
+               if (token_modifier_list.end() != std::find(token_modifier_list.begin(),
+                                                          token_modifier_list.end  (),
+                                                          modifier))
+               {
+                  return false;
+               }
+
+               token_modifier_list.push_back(modifier);
+
+               return true;
+            }
+
+            inline bool register_joiner(lexer::token_joiner* joiner)
+            {
+               if (token_joiner_list.end() != std::find(token_joiner_list.begin(),
+                                                        token_joiner_list.end  (),
+                                                        joiner))
+               {
+                  return false;
+               }
+
+               token_joiner_list.push_back(joiner);
+
+               return true;
+            }
+
+            inline bool register_inserter(lexer::token_inserter* inserter)
+            {
+               if (token_inserter_list.end() != std::find(token_inserter_list.begin(),
+                                                          token_inserter_list.end  (),
+                                                          inserter))
+               {
+                  return false;
+               }
+
+               token_inserter_list.push_back(inserter);
+
+               return true;
+            }
+
+            inline bool run_modifiers(lexer::generator& g)
+            {
+               error_token_modifier = reinterpret_cast<lexer::token_modifier*>(0);
+
+               for (std::size_t i = 0; i < token_modifier_list.size(); ++i)
+               {
+                  lexer::token_modifier& modifier = (*token_modifier_list[i]);
+
+                  modifier.reset();
+                  modifier.process(g);
+
+                  if (!modifier.result())
+                  {
+                     error_token_modifier = token_modifier_list[i];
+
+                     return false;
+                  }
+               }
+
+               return true;
+            }
+
+            inline bool run_joiners(lexer::generator& g)
+            {
+               error_token_joiner = reinterpret_cast<lexer::token_joiner*>(0);
+
+               for (std::size_t i = 0; i < token_joiner_list.size(); ++i)
+               {
+                  lexer::token_joiner& joiner = (*token_joiner_list[i]);
+
+                  joiner.reset();
+                  joiner.process(g);
+
+                  if (!joiner.result())
+                  {
+                     error_token_joiner = token_joiner_list[i];
+
+                     return false;
+                  }
+               }
+
+               return true;
+            }
+
+            inline bool run_inserters(lexer::generator& g)
+            {
+               error_token_inserter = reinterpret_cast<lexer::token_inserter*>(0);
+
+               for (std::size_t i = 0; i < token_inserter_list.size(); ++i)
+               {
+                  lexer::token_inserter& inserter = (*token_inserter_list[i]);
+
+                  inserter.reset();
+                  inserter.process(g);
+
+                  if (!inserter.result())
+                  {
+                     error_token_inserter = token_inserter_list[i];
+
+                     return false;
+                  }
+               }
+
+               return true;
+            }
+
+            inline bool run_scanners(lexer::generator& g)
+            {
+               error_token_scanner = reinterpret_cast<lexer::token_scanner*>(0);
+
+               for (std::size_t i = 0; i < token_scanner_list.size(); ++i)
+               {
+                  lexer::token_scanner& scanner = (*token_scanner_list[i]);
+
+                  scanner.reset();
+                  scanner.process(g);
+
+                  if (!scanner.result())
+                  {
+                     error_token_scanner = token_scanner_list[i];
+
+                     return false;
+                  }
+               }
+
+               return true;
+            }
+
+            std::vector<lexer::token_scanner*>  token_scanner_list;
+            std::vector<lexer::token_modifier*> token_modifier_list;
+            std::vector<lexer::token_joiner*>   token_joiner_list;
+            std::vector<lexer::token_inserter*> token_inserter_list;
+
+            lexer::token_scanner*  error_token_scanner;
+            lexer::token_modifier* error_token_modifier;
+            lexer::token_joiner*   error_token_joiner;
+            lexer::token_inserter* error_token_inserter;
+         };
+      }
+
+      class parser_helper
+      {
+      public:
+
+         typedef token         token_t;
+         typedef generator generator_t;
+
+         inline bool init(const std::string& str)
+         {
+            if (!lexer_.process(str))
+            {
+               return false;
+            }
+
+            lexer_.begin();
+
+            next_token();
+
+            return true;
+         }
+
+         inline generator_t& lexer()
+         {
+            return lexer_;
+         }
+
+         inline const generator_t& lexer() const
+         {
+            return lexer_;
+         }
+
+         inline void store_token()
+         {
+            lexer_.store();
+            store_current_token_ = current_token_;
+         }
+
+         inline void restore_token()
+         {
+            lexer_.restore();
+            current_token_ = store_current_token_;
+         }
+
+         inline void next_token()
+         {
+            current_token_ = lexer_.next_token();
+         }
+
+         inline const token_t& current_token() const
+         {
+            return current_token_;
+         }
+
+         enum token_advance_mode
+         {
+            e_hold    = 0,
+            e_advance = 1
+         };
+
+         inline void advance_token(const token_advance_mode mode)
+         {
+            if (e_advance == mode)
+            {
+               next_token();
+            }
+         }
+
+         inline bool token_is(const token_t::token_type& ttype, const token_advance_mode mode = e_advance)
+         {
+            if (current_token().type != ttype)
+            {
+               return false;
+            }
+
+            advance_token(mode);
+
+            return true;
+         }
+
+         inline bool token_is(const token_t::token_type& ttype,
+                              const std::string& value,
+                              const token_advance_mode mode = e_advance)
+         {
+            if (
+                 (current_token().type != ttype) ||
+                 !exprtk::details::imatch(value,current_token().value)
+               )
+            {
+               return false;
+            }
+
+            advance_token(mode);
+
+            return true;
+         }
+
+         inline bool peek_token_is(const token_t::token_type& ttype)
+         {
+            return (lexer_.peek_next_token().type == ttype);
+         }
+
+         inline bool peek_token_is(const std::string& s)
+         {
+            return (exprtk::details::imatch(lexer_.peek_next_token().value,s));
+         }
+
+      private:
+
+         generator_t lexer_;
+         token_t     current_token_;
+         token_t     store_current_token_;
+      };
+   }
+
+   template <typename T>
+   class vector_view
+   {
+   public:
+
+      typedef T* data_ptr_t;
+
+      vector_view(data_ptr_t data, const std::size_t& size)
+      : size_(size),
+        data_(data),
+        data_ref_(0)
+      {}
+
+      vector_view(const vector_view<T>& vv)
+      : size_(vv.size_),
+        data_(vv.data_),
+        data_ref_(0)
+      {}
+
+      inline void rebase(data_ptr_t data)
+      {
+         data_ = data;
+
+         if (!data_ref_.empty())
+         {
+            for (std::size_t i = 0; i < data_ref_.size(); ++i)
+            {
+               (*data_ref_[i]) = data;
+            }
+         }
+      }
+
+      inline data_ptr_t data() const
+      {
+         return data_;
+      }
+
+      inline std::size_t size() const
+      {
+         return size_;
+      }
+
+      inline const T& operator[](const std::size_t index) const
+      {
+         return data_[index];
+      }
+
+      inline T& operator[](const std::size_t index)
+      {
+         return data_[index];
+      }
+
+      void set_ref(data_ptr_t* data_ref)
+      {
+         data_ref_.push_back(data_ref);
+      }
+
+   private:
+
+      const std::size_t size_;
+      data_ptr_t  data_;
+      std::vector<data_ptr_t*> data_ref_;
+   };
+
+   template <typename T>
+   inline vector_view<T> make_vector_view(T* data,
+                                          const std::size_t size, const std::size_t offset = 0)
+   {
+      return vector_view<T>(data + offset, size);
+   }
+
+   template <typename T>
+   inline vector_view<T> make_vector_view(std::vector<T>& v,
+                                          const std::size_t size, const std::size_t offset = 0)
+   {
+      return vector_view<T>(v.data() + offset, size);
+   }
+
+   template <typename T> class results_context;
+
+   template <typename T>
+   struct type_store
+   {
+      enum store_type
+      {
+         e_unknown,
+         e_scalar ,
+         e_vector ,
+         e_string
+      };
+
+      type_store()
+      : data(0),
+        size(0),
+        type(e_unknown)
+      {}
+
+      union
+      {
+          void*  data;
+          T*     vec_data;
+      };
+
+      std::size_t size;
+      store_type  type;
+
+      class parameter_list
+      {
+      public:
+
+         parameter_list(std::vector<type_store>& pl)
+         : parameter_list_(pl)
+         {}
+
+         inline bool empty() const
+         {
+            return parameter_list_.empty();
+         }
+
+         inline std::size_t size() const
+         {
+            return parameter_list_.size();
+         }
+
+         inline type_store& operator[](const std::size_t& index)
+         {
+            return parameter_list_[index];
+         }
+
+         inline const type_store& operator[](const std::size_t& index) const
+         {
+            return parameter_list_[index];
+         }
+
+         inline type_store& front()
+         {
+            return parameter_list_[0];
+         }
+
+         inline const type_store& front() const
+         {
+            return parameter_list_[0];
+         }
+
+         inline type_store& back()
+         {
+            return parameter_list_.back();
+         }
+
+         inline const type_store& back() const
+         {
+            return parameter_list_.back();
+         }
+
+      private:
+
+         std::vector<type_store>& parameter_list_;
+
+         friend class results_context<T>;
+      };
+
+      template <typename ViewType>
+      struct type_view
+      {
+         typedef type_store<T> type_store_t;
+         typedef ViewType      value_t;
+
+         type_view(type_store_t& ts)
+         : ts_(ts),
+           data_(reinterpret_cast<value_t*>(ts_.data))
+         {}
+
+         type_view(const type_store_t& ts)
+         : ts_(const_cast<type_store_t&>(ts)),
+           data_(reinterpret_cast<value_t*>(ts_.data))
+         {}
+
+         inline std::size_t size() const
+         {
+            return ts_.size;
+         }
+
+         inline value_t& operator[](const std::size_t& i)
+         {
+            return data_[i];
+         }
+
+         inline const value_t& operator[](const std::size_t& i) const
+         {
+            return data_[i];
+         }
+
+         inline const value_t* begin() const { return data_; }
+         inline       value_t* begin()       { return data_; }
+
+         inline const value_t* end() const
+         {
+            return static_cast<value_t*>(data_ + ts_.size);
+         }
+
+         inline value_t* end()
+         {
+            return static_cast<value_t*>(data_ + ts_.size);
+         }
+
+         type_store_t& ts_;
+         value_t* data_;
+      };
+
+      typedef type_view<T>    vector_view;
+      typedef type_view<char> string_view;
+
+      struct scalar_view
+      {
+         typedef type_store<T> type_store_t;
+         typedef T value_t;
+
+         scalar_view(type_store_t& ts)
+         : v_(*reinterpret_cast<value_t*>(ts.data))
+         {}
+
+         scalar_view(const type_store_t& ts)
+         : v_(*reinterpret_cast<value_t*>(const_cast<type_store_t&>(ts).data))
+         {}
+
+         inline value_t& operator() ()
+         {
+            return v_;
+         }
+
+         inline const value_t& operator() () const
+         {
+            return v_;
+         }
+
+         template <typename IntType>
+         inline bool to_int(IntType& i) const
+         {
+            if (!exprtk::details::numeric::is_integer(v_))
+               return false;
+
+            i = static_cast<IntType>(v_);
+
+            return true;
+         }
+
+         template <typename UIntType>
+         inline bool to_uint(UIntType& u) const
+         {
+            if (v_ < T(0))
+               return false;
+            else if (!exprtk::details::numeric::is_integer(v_))
+               return false;
+
+            u = static_cast<UIntType>(v_);
+
+            return true;
+         }
+
+         T& v_;
+      };
+   };
+
+   template <typename StringView>
+   inline std::string to_str(const StringView& view)
+   {
+      return std::string(view.begin(),view.size());
+   }
+
+   #ifndef exprtk_disable_return_statement
+   namespace details
+   {
+      template <typename T> class return_node;
+      template <typename T> class return_envelope_node;
+   }
+   #endif
+
+   template <typename T>
+   class results_context
+   {
+   public:
+
+      typedef type_store<T> type_store_t;
+
+      results_context()
+      : results_available_(false)
+      {}
+
+      inline std::size_t count() const
+      {
+         if (results_available_)
+            return parameter_list_.size();
+         else
+            return 0;
+      }
+
+      inline type_store_t& operator[](const std::size_t& index)
+      {
+         return parameter_list_[index];
+      }
+
+      inline const type_store_t& operator[](const std::size_t& index) const
+      {
+         return parameter_list_[index];
+      }
+
+   private:
+
+      inline void clear()
+      {
+         results_available_ = false;
+      }
+
+      typedef std::vector<type_store_t> ts_list_t;
+      typedef typename type_store_t::parameter_list parameter_list_t;
+
+      inline void assign(const parameter_list_t& pl)
+      {
+         parameter_list_    = pl.parameter_list_;
+         results_available_ = true;
+      }
+
+      bool results_available_;
+      ts_list_t parameter_list_;
+
+      #ifndef exprtk_disable_return_statement
+      friend class details::return_node<T>;
+      friend class details::return_envelope_node<T>;
+      #endif
+   };
+
+   namespace details
+   {
+      enum operator_type
+      {
+         e_default , e_null    , e_add     , e_sub     ,
+         e_mul     , e_div     , e_mod     , e_pow     ,
+         e_atan2   , e_min     , e_max     , e_avg     ,
+         e_sum     , e_prod    , e_lt      , e_lte     ,
+         e_eq      , e_equal   , e_ne      , e_nequal  ,
+         e_gte     , e_gt      , e_and     , e_nand    ,
+         e_or      , e_nor     , e_xor     , e_xnor    ,
+         e_mand    , e_mor     , e_scand   , e_scor    ,
+         e_shr     , e_shl     , e_abs     , e_acos    ,
+         e_acosh   , e_asin    , e_asinh   , e_atan    ,
+         e_atanh   , e_ceil    , e_cos     , e_cosh    ,
+         e_exp     , e_expm1   , e_floor   , e_log     ,
+         e_log10   , e_log2    , e_log1p   , e_logn    ,
+         e_neg     , e_pos     , e_round   , e_roundn  ,
+         e_root    , e_sqrt    , e_sin     , e_sinc    ,
+         e_sinh    , e_sec     , e_csc     , e_tan     ,
+         e_tanh    , e_cot     , e_clamp   , e_iclamp  ,
+         e_inrange , e_sgn     , e_r2d     , e_d2r     ,
+         e_d2g     , e_g2d     , e_hypot   , e_notl    ,
+         e_erf     , e_erfc    , e_ncdf    , e_frac    ,
+         e_trunc   , e_assign  , e_addass  , e_subass  ,
+         e_mulass  , e_divass  , e_modass  , e_in      ,
+         e_like    , e_ilike   , e_multi   , e_smulti  ,
+         e_swap    ,
+
+         // Do not add new functions/operators after this point.
+         e_sf00 = 1000, e_sf01 = 1001, e_sf02 = 1002, e_sf03 = 1003,
+         e_sf04 = 1004, e_sf05 = 1005, e_sf06 = 1006, e_sf07 = 1007,
+         e_sf08 = 1008, e_sf09 = 1009, e_sf10 = 1010, e_sf11 = 1011,
+         e_sf12 = 1012, e_sf13 = 1013, e_sf14 = 1014, e_sf15 = 1015,
+         e_sf16 = 1016, e_sf17 = 1017, e_sf18 = 1018, e_sf19 = 1019,
+         e_sf20 = 1020, e_sf21 = 1021, e_sf22 = 1022, e_sf23 = 1023,
+         e_sf24 = 1024, e_sf25 = 1025, e_sf26 = 1026, e_sf27 = 1027,
+         e_sf28 = 1028, e_sf29 = 1029, e_sf30 = 1030, e_sf31 = 1031,
+         e_sf32 = 1032, e_sf33 = 1033, e_sf34 = 1034, e_sf35 = 1035,
+         e_sf36 = 1036, e_sf37 = 1037, e_sf38 = 1038, e_sf39 = 1039,
+         e_sf40 = 1040, e_sf41 = 1041, e_sf42 = 1042, e_sf43 = 1043,
+         e_sf44 = 1044, e_sf45 = 1045, e_sf46 = 1046, e_sf47 = 1047,
+         e_sf48 = 1048, e_sf49 = 1049, e_sf50 = 1050, e_sf51 = 1051,
+         e_sf52 = 1052, e_sf53 = 1053, e_sf54 = 1054, e_sf55 = 1055,
+         e_sf56 = 1056, e_sf57 = 1057, e_sf58 = 1058, e_sf59 = 1059,
+         e_sf60 = 1060, e_sf61 = 1061, e_sf62 = 1062, e_sf63 = 1063,
+         e_sf64 = 1064, e_sf65 = 1065, e_sf66 = 1066, e_sf67 = 1067,
+         e_sf68 = 1068, e_sf69 = 1069, e_sf70 = 1070, e_sf71 = 1071,
+         e_sf72 = 1072, e_sf73 = 1073, e_sf74 = 1074, e_sf75 = 1075,
+         e_sf76 = 1076, e_sf77 = 1077, e_sf78 = 1078, e_sf79 = 1079,
+         e_sf80 = 1080, e_sf81 = 1081, e_sf82 = 1082, e_sf83 = 1083,
+         e_sf84 = 1084, e_sf85 = 1085, e_sf86 = 1086, e_sf87 = 1087,
+         e_sf88 = 1088, e_sf89 = 1089, e_sf90 = 1090, e_sf91 = 1091,
+         e_sf92 = 1092, e_sf93 = 1093, e_sf94 = 1094, e_sf95 = 1095,
+         e_sf96 = 1096, e_sf97 = 1097, e_sf98 = 1098, e_sf99 = 1099,
+         e_sffinal  = 1100,
+         e_sf4ext00 = 2000, e_sf4ext01 = 2001, e_sf4ext02 = 2002, e_sf4ext03 = 2003,
+         e_sf4ext04 = 2004, e_sf4ext05 = 2005, e_sf4ext06 = 2006, e_sf4ext07 = 2007,
+         e_sf4ext08 = 2008, e_sf4ext09 = 2009, e_sf4ext10 = 2010, e_sf4ext11 = 2011,
+         e_sf4ext12 = 2012, e_sf4ext13 = 2013, e_sf4ext14 = 2014, e_sf4ext15 = 2015,
+         e_sf4ext16 = 2016, e_sf4ext17 = 2017, e_sf4ext18 = 2018, e_sf4ext19 = 2019,
+         e_sf4ext20 = 2020, e_sf4ext21 = 2021, e_sf4ext22 = 2022, e_sf4ext23 = 2023,
+         e_sf4ext24 = 2024, e_sf4ext25 = 2025, e_sf4ext26 = 2026, e_sf4ext27 = 2027,
+         e_sf4ext28 = 2028, e_sf4ext29 = 2029, e_sf4ext30 = 2030, e_sf4ext31 = 2031,
+         e_sf4ext32 = 2032, e_sf4ext33 = 2033, e_sf4ext34 = 2034, e_sf4ext35 = 2035,
+         e_sf4ext36 = 2036, e_sf4ext37 = 2037, e_sf4ext38 = 2038, e_sf4ext39 = 2039,
+         e_sf4ext40 = 2040, e_sf4ext41 = 2041, e_sf4ext42 = 2042, e_sf4ext43 = 2043,
+         e_sf4ext44 = 2044, e_sf4ext45 = 2045, e_sf4ext46 = 2046, e_sf4ext47 = 2047,
+         e_sf4ext48 = 2048, e_sf4ext49 = 2049, e_sf4ext50 = 2050, e_sf4ext51 = 2051,
+         e_sf4ext52 = 2052, e_sf4ext53 = 2053, e_sf4ext54 = 2054, e_sf4ext55 = 2055,
+         e_sf4ext56 = 2056, e_sf4ext57 = 2057, e_sf4ext58 = 2058, e_sf4ext59 = 2059,
+         e_sf4ext60 = 2060, e_sf4ext61 = 2061
+      };
+
+      inline std::string to_str(const operator_type opr)
+      {
+         switch (opr)
+         {
+            case e_add    : return  "+"  ;
+            case e_sub    : return  "-"  ;
+            case e_mul    : return  "*"  ;
+            case e_div    : return  "/"  ;
+            case e_mod    : return  "%"  ;
+            case e_pow    : return  "^"  ;
+            case e_assign : return ":="  ;
+            case e_addass : return "+="  ;
+            case e_subass : return "-="  ;
+            case e_mulass : return "*="  ;
+            case e_divass : return "/="  ;
+            case e_modass : return "%="  ;
+            case e_lt     : return  "<"  ;
+            case e_lte    : return "<="  ;
+            case e_eq     : return "=="  ;
+            case e_equal  : return  "="  ;
+            case e_ne     : return "!="  ;
+            case e_nequal : return "<>"  ;
+            case e_gte    : return ">="  ;
+            case e_gt     : return  ">"  ;
+            case e_and    : return "and" ;
+            case e_or     : return "or"  ;
+            case e_xor    : return "xor" ;
+            case e_nand   : return "nand";
+            case e_nor    : return "nor" ;
+            case e_xnor   : return "xnor";
+            default       : return "N/A" ;
+         }
+      }
+
+      struct base_operation_t
+      {
+         base_operation_t(const operator_type t, const unsigned int& np)
+         : type(t),
+           num_params(np)
+         {}
+
+         operator_type type;
+         unsigned int num_params;
+      };
+
+      namespace loop_unroll
+      {
+         #ifndef exprtk_disable_superscalar_unroll
+         const unsigned int global_loop_batch_size = 16;
+         #else
+         const unsigned int global_loop_batch_size = 4;
+         #endif
+
+         struct details
+         {
+            details(const std::size_t& vsize,
+                    const unsigned int loop_batch_size = global_loop_batch_size)
+            : batch_size(loop_batch_size   ),
+              remainder (vsize % batch_size),
+              upper_bound(static_cast<int>(vsize - (remainder ? loop_batch_size : 0)))
+            {}
+
+            unsigned int batch_size;
+            int   remainder;
+            int upper_bound;
+         };
+      }
+
+      #ifdef exprtk_enable_debugging
+      inline void dump_ptr(const std::string& s, const void* ptr, const std::size_t size = 0)
+      {
+         if (size)
+            exprtk_debug(("%s - addr: %p\n",s.c_str(),ptr));
+         else
+            exprtk_debug(("%s - addr: %p size: %d\n",
+                          s.c_str(),
+                          ptr,
+                          static_cast<unsigned int>(size)));
+      }
+      #else
+      inline void dump_ptr(const std::string&, const void*) {}
+      inline void dump_ptr(const std::string&, const void*, const std::size_t) {}
+      #endif
+
+      template <typename T>
+      class vec_data_store
+      {
+      public:
+
+         typedef vec_data_store<T> type;
+         typedef T* data_t;
+
+      private:
+
+         struct control_block
+         {
+            control_block()
+            : ref_count(1),
+              size     (0),
+              data     (0),
+              destruct (true)
+            {}
+
+            control_block(const std::size_t& dsize)
+            : ref_count(1    ),
+              size     (dsize),
+              data     (0    ),
+              destruct (true )
+            { create_data(); }
+
+            control_block(const std::size_t& dsize, data_t dptr, bool dstrct = false)
+            : ref_count(1     ),
+              size     (dsize ),
+              data     (dptr  ),
+              destruct (dstrct)
+            {}
+
+           ~control_block()
+            {
+               if (data && destruct && (0 == ref_count))
+               {
+                  dump_ptr("~control_block() data",data);
+                  delete[] data;
+                  data = reinterpret_cast<data_t>(0);
+               }
+            }
+
+            static inline control_block* create(const std::size_t& dsize, data_t data_ptr = data_t(0), bool dstrct = false)
+            {
+               if (dsize)
+               {
+                  if (0 == data_ptr)
+                     return (new control_block(dsize));
+                  else
+                     return (new control_block(dsize, data_ptr, dstrct));
+               }
+               else
+                  return (new control_block);
+            }
+
+            static inline void destroy(control_block*& cntrl_blck)
+            {
+               if (cntrl_blck)
+               {
+                  if (
+                       (0 !=   cntrl_blck->ref_count) &&
+                       (0 == --cntrl_blck->ref_count)
+                     )
+                  {
+                     delete cntrl_blck;
+                  }
+
+                  cntrl_blck = 0;
+               }
+            }
+
+            std::size_t ref_count;
+            std::size_t size;
+            data_t      data;
+            bool        destruct;
+
+         private:
+
+            control_block(const control_block&);
+            control_block& operator=(const control_block&);
+
+            inline void create_data()
+            {
+               destruct = true;
+               data     = new T[size];
+               std::fill_n(data,size,T(0));
+               dump_ptr("control_block::create_data() - data",data,size);
+            }
+         };
+
+      public:
+
+         vec_data_store()
+         : control_block_(control_block::create(0))
+         {}
+
+         vec_data_store(const std::size_t& size)
+         : control_block_(control_block::create(size,(data_t)(0),true))
+         {}
+
+         vec_data_store(const std::size_t& size, data_t data, bool dstrct = false)
+         : control_block_(control_block::create(size, data, dstrct))
+         {}
+
+         vec_data_store(const type& vds)
+         {
+            control_block_ = vds.control_block_;
+            control_block_->ref_count++;
+         }
+
+        ~vec_data_store()
+         {
+            control_block::destroy(control_block_);
+         }
+
+         type& operator=(const type& vds)
+         {
+            if (this != &vds)
+            {
+               std::size_t final_size = min_size(control_block_, vds.control_block_);
+
+               vds.control_block_->size = final_size;
+                   control_block_->size = final_size;
+
+               if (control_block_->destruct || (0 == control_block_->data))
+               {
+                  control_block::destroy(control_block_);
+
+                  control_block_ = vds.control_block_;
+                  control_block_->ref_count++;
+               }
+            }
+
+            return (*this);
+         }
+
+         inline data_t data()
+         {
+            return control_block_->data;
+         }
+
+         inline data_t data() const
+         {
+            return control_block_->data;
+         }
+
+         inline std::size_t size()
+         {
+            return control_block_->size;
+         }
+
+         inline std::size_t size() const
+         {
+            return control_block_->size;
+         }
+
+         inline data_t& ref()
+         {
+            return control_block_->data;
+         }
+
+         inline void dump() const
+         {
+            #ifdef exprtk_enable_debugging
+            exprtk_debug(("size: %d\taddress:%p\tdestruct:%c\n",
+                          size(),
+                          data(),
+                          (control_block_->destruct ? 'T' : 'F')));
+
+            for (std::size_t i = 0; i < size(); ++i)
+            {
+               if (5 == i)
+                  exprtk_debug(("\n"));
+
+               exprtk_debug(("%15.10f ",data()[i]));
+            }
+            exprtk_debug(("\n"));
+            #endif
+         }
+
+         static inline void match_sizes(type& vds0, type& vds1)
+         {
+            std::size_t size = min_size(vds0.control_block_,vds1.control_block_);
+            vds0.control_block_->size = size;
+            vds1.control_block_->size = size;
+         }
+
+      private:
+
+         static inline std::size_t min_size(control_block* cb0, control_block* cb1)
+         {
+            const std::size_t size0 = cb0->size;
+            const std::size_t size1 = cb1->size;
+
+            if (size0 && size1)
+               return std::min(size0,size1);
+            else
+               return (size0) ? size0 : size1;
+         }
+
+         control_block* control_block_;
+      };
+
+      namespace numeric
+      {
+         namespace details
+         {
+            template <typename T>
+            inline T process_impl(const operator_type operation, const T arg)
+            {
+               switch (operation)
+               {
+                  case e_abs   : return numeric::abs  (arg);
+                  case e_acos  : return numeric::acos (arg);
+                  case e_acosh : return numeric::acosh(arg);
+                  case e_asin  : return numeric::asin (arg);
+                  case e_asinh : return numeric::asinh(arg);
+                  case e_atan  : return numeric::atan (arg);
+                  case e_atanh : return numeric::atanh(arg);
+                  case e_ceil  : return numeric::ceil (arg);
+                  case e_cos   : return numeric::cos  (arg);
+                  case e_cosh  : return numeric::cosh (arg);
+                  case e_exp   : return numeric::exp  (arg);
+                  case e_expm1 : return numeric::expm1(arg);
+                  case e_floor : return numeric::floor(arg);
+                  case e_log   : return numeric::log  (arg);
+                  case e_log10 : return numeric::log10(arg);
+                  case e_log2  : return numeric::log2 (arg);
+                  case e_log1p : return numeric::log1p(arg);
+                  case e_neg   : return numeric::neg  (arg);
+                  case e_pos   : return numeric::pos  (arg);
+                  case e_round : return numeric::round(arg);
+                  case e_sin   : return numeric::sin  (arg);
+                  case e_sinc  : return numeric::sinc (arg);
+                  case e_sinh  : return numeric::sinh (arg);
+                  case e_sqrt  : return numeric::sqrt (arg);
+                  case e_tan   : return numeric::tan  (arg);
+                  case e_tanh  : return numeric::tanh (arg);
+                  case e_cot   : return numeric::cot  (arg);
+                  case e_sec   : return numeric::sec  (arg);
+                  case e_csc   : return numeric::csc  (arg);
+                  case e_r2d   : return numeric::r2d  (arg);
+                  case e_d2r   : return numeric::d2r  (arg);
+                  case e_d2g   : return numeric::d2g  (arg);
+                  case e_g2d   : return numeric::g2d  (arg);
+                  case e_notl  : return numeric::notl (arg);
+                  case e_sgn   : return numeric::sgn  (arg);
+                  case e_erf   : return numeric::erf  (arg);
+                  case e_erfc  : return numeric::erfc (arg);
+                  case e_ncdf  : return numeric::ncdf (arg);
+                  case e_frac  : return numeric::frac (arg);
+                  case e_trunc : return numeric::trunc(arg);
+
+                  default      : exprtk_debug(("numeric::details::process_impl<T> - Invalid unary operation.\n"));
+                                 return std::numeric_limits<T>::quiet_NaN();
+               }
+            }
+
+            template <typename T>
+            inline T process_impl(const operator_type operation, const T arg0, const T arg1)
+            {
+               switch (operation)
+               {
+                  case e_add    : return (arg0 + arg1);
+                  case e_sub    : return (arg0 - arg1);
+                  case e_mul    : return (arg0 * arg1);
+                  case e_div    : return (arg0 / arg1);
+                  case e_mod    : return modulus<T>(arg0,arg1);
+                  case e_pow    : return pow<T>(arg0,arg1);
+                  case e_atan2  : return atan2<T>(arg0,arg1);
+                  case e_min    : return std::min<T>(arg0,arg1);
+                  case e_max    : return std::max<T>(arg0,arg1);
+                  case e_logn   : return logn<T>(arg0,arg1);
+                  case e_lt     : return (arg0 <  arg1) ? T(1) : T(0);
+                  case e_lte    : return (arg0 <= arg1) ? T(1) : T(0);
+                  case e_eq     : return std::equal_to<T>()(arg0,arg1) ? T(1) : T(0);
+                  case e_ne     : return std::not_equal_to<T>()(arg0,arg1) ? T(1) : T(0);
+                  case e_gte    : return (arg0 >= arg1) ? T(1) : T(0);
+                  case e_gt     : return (arg0 >  arg1) ? T(1) : T(0);
+                  case e_and    : return and_opr <T>(arg0,arg1);
+                  case e_nand   : return nand_opr<T>(arg0,arg1);
+                  case e_or     : return or_opr  <T>(arg0,arg1);
+                  case e_nor    : return nor_opr <T>(arg0,arg1);
+                  case e_xor    : return xor_opr <T>(arg0,arg1);
+                  case e_xnor   : return xnor_opr<T>(arg0,arg1);
+                  case e_root   : return root    <T>(arg0,arg1);
+                  case e_roundn : return roundn  <T>(arg0,arg1);
+                  case e_equal  : return equal      (arg0,arg1);
+                  case e_nequal : return nequal     (arg0,arg1);
+                  case e_hypot  : return hypot   <T>(arg0,arg1);
+                  case e_shr    : return shr     <T>(arg0,arg1);
+                  case e_shl    : return shl     <T>(arg0,arg1);
+
+                  default       : exprtk_debug(("numeric::details::process_impl<T> - Invalid binary operation.\n"));
+                                  return std::numeric_limits<T>::quiet_NaN();
+               }
+            }
+
+            template <typename T>
+            inline T process_impl(const operator_type operation, const T arg0, const T arg1, int_type_tag)
+            {
+               switch (operation)
+               {
+                  case e_add    : return (arg0 + arg1);
+                  case e_sub    : return (arg0 - arg1);
+                  case e_mul    : return (arg0 * arg1);
+                  case e_div    : return (arg0 / arg1);
+                  case e_mod    : return arg0 % arg1;
+                  case e_pow    : return pow<T>(arg0,arg1);
+                  case e_min    : return std::min<T>(arg0,arg1);
+                  case e_max    : return std::max<T>(arg0,arg1);
+                  case e_logn   : return logn<T>(arg0,arg1);
+                  case e_lt     : return (arg0 <  arg1) ? T(1) : T(0);
+                  case e_lte    : return (arg0 <= arg1) ? T(1) : T(0);
+                  case e_eq     : return (arg0 == arg1) ? T(1) : T(0);
+                  case e_ne     : return (arg0 != arg1) ? T(1) : T(0);
+                  case e_gte    : return (arg0 >= arg1) ? T(1) : T(0);
+                  case e_gt     : return (arg0 >  arg1) ? T(1) : T(0);
+                  case e_and    : return ((arg0 != T(0)) && (arg1 != T(0))) ? T(1) : T(0);
+                  case e_nand   : return ((arg0 != T(0)) && (arg1 != T(0))) ? T(0) : T(1);
+                  case e_or     : return ((arg0 != T(0)) || (arg1 != T(0))) ? T(1) : T(0);
+                  case e_nor    : return ((arg0 != T(0)) || (arg1 != T(0))) ? T(0) : T(1);
+                  case e_xor    : return arg0 ^ arg1;
+                  case e_xnor   : return !(arg0 ^ arg1);
+                  case e_root   : return root<T>(arg0,arg1);
+                  case e_equal  : return arg0 == arg1;
+                  case e_nequal : return arg0 != arg1;
+                  case e_hypot  : return hypot<T>(arg0,arg1);
+                  case e_shr    : return arg0 >> arg1;
+                  case e_shl    : return arg0 << arg1;
+
+                  default       : exprtk_debug(("numeric::details::process_impl<IntType> - Invalid binary operation.\n"));
+                                  return std::numeric_limits<T>::quiet_NaN();
+               }
+            }
+         }
+
+         template <typename T>
+         inline T process(const operator_type operation, const T arg)
+         {
+            return exprtk::details::numeric::details::process_impl(operation,arg);
+         }
+
+         template <typename T>
+         inline T process(const operator_type operation, const T arg0, const T arg1)
+         {
+            return exprtk::details::numeric::details::process_impl(operation, arg0, arg1);
+         }
+      }
+
+      template <typename T>
+      class expression_node
+      {
+      public:
+
+         enum node_type
+         {
+            e_none          , e_null          , e_constant    , e_unary        ,
+            e_binary        , e_binary_ext    , e_trinary     , e_quaternary   ,
+            e_vararg        , e_conditional   , e_while       , e_repeat       ,
+            e_for           , e_switch        , e_mswitch     , e_return       ,
+            e_retenv        , e_variable      , e_stringvar   , e_stringconst  ,
+            e_stringvarrng  , e_cstringvarrng , e_strgenrange , e_strconcat    ,
+            e_stringvarsize , e_strswap       , e_stringsize  , e_stringvararg ,
+            e_function      , e_vafunction    , e_genfunction , e_strfunction  ,
+            e_strcondition  , e_strccondition , e_add         , e_sub          ,
+            e_mul           , e_div           , e_mod         , e_pow          ,
+            e_lt            , e_lte           , e_gt          , e_gte          ,
+            e_eq            , e_ne            , e_and         , e_nand         ,
+            e_or            , e_nor           , e_xor         , e_xnor         ,
+            e_in            , e_like          , e_ilike       , e_inranges     ,
+            e_ipow          , e_ipowinv       , e_abs         , e_acos         ,
+            e_acosh         , e_asin          , e_asinh       , e_atan         ,
+            e_atanh         , e_ceil          , e_cos         , e_cosh         ,
+            e_exp           , e_expm1         , e_floor       , e_log          ,
+            e_log10         , e_log2          , e_log1p       , e_neg          ,
+            e_pos           , e_round         , e_sin         , e_sinc         ,
+            e_sinh          , e_sqrt          , e_tan         , e_tanh         ,
+            e_cot           , e_sec           , e_csc         , e_r2d          ,
+            e_d2r           , e_d2g           , e_g2d         , e_notl         ,
+            e_sgn           , e_erf           , e_erfc        , e_ncdf         ,
+            e_frac          , e_trunc         , e_uvouv       , e_vov          ,
+            e_cov           , e_voc           , e_vob         , e_bov          ,
+            e_cob           , e_boc           , e_vovov       , e_vovoc        ,
+            e_vocov         , e_covov         , e_covoc       , e_vovovov      ,
+            e_vovovoc       , e_vovocov       , e_vocovov     , e_covovov      ,
+            e_covocov       , e_vocovoc       , e_covovoc     , e_vococov      ,
+            e_sf3ext        , e_sf4ext        , e_nulleq      , e_strass       ,
+            e_vector        , e_vecelem       , e_rbvecelem   , e_rbveccelem   ,
+            e_vecdefass     , e_vecvalass     , e_vecvecass   , e_vecopvalass  ,
+            e_vecopvecass   , e_vecfunc       , e_vecvecswap  , e_vecvecineq   ,
+            e_vecvalineq    , e_valvecineq    , e_vecvecarith , e_vecvalarith  ,
+            e_valvecarith   , e_vecunaryop    , e_break       , e_continue     ,
+            e_swap
+         };
+
+         typedef T value_type;
+         typedef expression_node<T>* expression_ptr;
+
+         virtual ~expression_node()
+         {}
+
+         inline virtual T value() const
+         {
+            return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         inline virtual expression_node<T>* branch(const std::size_t& index = 0) const
+         {
+            return reinterpret_cast<expression_ptr>(index * 0);
+         }
+
+         inline virtual node_type type() const
+         {
+            return e_none;
+         }
+      };
+
+      template <typename T>
+      inline bool is_generally_string_node(const expression_node<T>* node);
+
+      inline bool is_true(const double v)
+      {
+         return std::not_equal_to<double>()(0.0,v);
+      }
+
+      inline bool is_true(const long double v)
+      {
+         return std::not_equal_to<long double>()(0.0L,v);
+      }
+
+      inline bool is_true(const float v)
+      {
+         return std::not_equal_to<float>()(0.0f,v);
+      }
+
+      template <typename T>
+      inline bool is_true(const std::complex<T>& v)
+      {
+         return std::not_equal_to<std::complex<T> >()(std::complex<T>(0),v);
+      }
+
+      template <typename T>
+      inline bool is_true(const expression_node<T>* node)
+      {
+         return std::not_equal_to<T>()(T(0),node->value());
+      }
+
+      template <typename T>
+      inline bool is_false(const expression_node<T>* node)
+      {
+         return std::equal_to<T>()(T(0),node->value());
+      }
+
+      template <typename T>
+      inline bool is_unary_node(const expression_node<T>* node)
+      {
+         return node && (details::expression_node<T>::e_unary == node->type());
+      }
+
+      template <typename T>
+      inline bool is_neg_unary_node(const expression_node<T>* node)
+      {
+         return node && (details::expression_node<T>::e_neg == node->type());
+      }
+
+      template <typename T>
+      inline bool is_binary_node(const expression_node<T>* node)
+      {
+         return node && (details::expression_node<T>::e_binary == node->type());
+      }
+
+      template <typename T>
+      inline bool is_variable_node(const expression_node<T>* node)
+      {
+         return node && (details::expression_node<T>::e_variable == node->type());
+      }
+
+      template <typename T>
+      inline bool is_ivariable_node(const expression_node<T>* node)
+      {
+         return node &&
+                (
+                  details::expression_node<T>::e_variable   == node->type() ||
+                  details::expression_node<T>::e_vecelem    == node->type() ||
+                  details::expression_node<T>::e_rbvecelem  == node->type() ||
+                  details::expression_node<T>::e_rbveccelem == node->type()
+                );
+      }
+
+      template <typename T>
+      inline bool is_vector_elem_node(const expression_node<T>* node)
+      {
+         return node && (details::expression_node<T>::e_vecelem == node->type());
+      }
+
+      template <typename T>
+      inline bool is_rebasevector_elem_node(const expression_node<T>* node)
+      {
+         return node && (details::expression_node<T>::e_rbvecelem == node->type());
+      }
+
+      template <typename T>
+      inline bool is_rebasevector_celem_node(const expression_node<T>* node)
+      {
+         return node && (details::expression_node<T>::e_rbveccelem == node->type());
+      }
+
+      template <typename T>
+      inline bool is_vector_node(const expression_node<T>* node)
+      {
+         return node && (details::expression_node<T>::e_vector == node->type());
+      }
+
+      template <typename T>
+      inline bool is_ivector_node(const expression_node<T>* node)
+      {
+         if (node)
+         {
+            switch (node->type())
+            {
+               case details::expression_node<T>::e_vector      :
+               case details::expression_node<T>::e_vecvalass   :
+               case details::expression_node<T>::e_vecvecass   :
+               case details::expression_node<T>::e_vecopvalass :
+               case details::expression_node<T>::e_vecopvecass :
+               case details::expression_node<T>::e_vecvecswap  :
+               case details::expression_node<T>::e_vecvecarith :
+               case details::expression_node<T>::e_vecvalarith :
+               case details::expression_node<T>::e_valvecarith :
+               case details::expression_node<T>::e_vecunaryop  : return true;
+               default                                         : return false;
+            }
+         }
+         else
+            return false;
+      }
+
+      template <typename T>
+      inline bool is_constant_node(const expression_node<T>* node)
+      {
+         return node && (details::expression_node<T>::e_constant == node->type());
+      }
+
+      template <typename T>
+      inline bool is_null_node(const expression_node<T>* node)
+      {
+         return node && (details::expression_node<T>::e_null == node->type());
+      }
+
+      template <typename T>
+      inline bool is_break_node(const expression_node<T>* node)
+      {
+         return node && (details::expression_node<T>::e_break == node->type());
+      }
+
+      template <typename T>
+      inline bool is_continue_node(const expression_node<T>* node)
+      {
+         return node && (details::expression_node<T>::e_continue == node->type());
+      }
+
+      template <typename T>
+      inline bool is_swap_node(const expression_node<T>* node)
+      {
+         return node && (details::expression_node<T>::e_swap == node->type());
+      }
+
+      template <typename T>
+      inline bool is_function(const expression_node<T>* node)
+      {
+         return node && (details::expression_node<T>::e_function == node->type());
+      }
+
+      template <typename T>
+      inline bool is_return_node(const expression_node<T>* node)
+      {
+         return node && (details::expression_node<T>::e_return == node->type());
+      }
+
+      template <typename T> class unary_node;
+
+      template <typename T>
+      inline bool is_negate_node(const expression_node<T>* node)
+      {
+         if (node && is_unary_node(node))
+         {
+            return (details::e_neg == static_cast<const unary_node<T>*>(node)->operation());
+         }
+         else
+            return false;
+      }
+
+      template <typename T>
+      inline bool branch_deletable(expression_node<T>* node)
+      {
+         return !is_variable_node(node) &&
+                !is_string_node  (node) ;
+      }
+
+      template <std::size_t N, typename T>
+      inline bool all_nodes_valid(expression_node<T>* (&b)[N])
+      {
+         for (std::size_t i = 0; i < N; ++i)
+         {
+            if (0 == b[i]) return false;
+         }
+
+         return true;
+      }
+
+      template <typename T,
+                typename Allocator,
+                template <typename, typename> class Sequence>
+      inline bool all_nodes_valid(const Sequence<expression_node<T>*,Allocator>& b)
+      {
+         for (std::size_t i = 0; i < b.size(); ++i)
+         {
+            if (0 == b[i]) return false;
+         }
+
+         return true;
+      }
+
+      template <std::size_t N, typename T>
+      inline bool all_nodes_variables(expression_node<T>* (&b)[N])
+      {
+         for (std::size_t i = 0; i < N; ++i)
+         {
+            if (0 == b[i])
+               return false;
+            else if (!is_variable_node(b[i]))
+               return false;
+         }
+
+         return true;
+      }
+
+      template <typename T,
+                typename Allocator,
+                template <typename, typename> class Sequence>
+      inline bool all_nodes_variables(Sequence<expression_node<T>*,Allocator>& b)
+      {
+         for (std::size_t i = 0; i < b.size(); ++i)
+         {
+            if (0 == b[i])
+               return false;
+            else if (!is_variable_node(b[i]))
+               return false;
+         }
+
+         return true;
+      }
+
+      template <typename NodeAllocator, typename T, std::size_t N>
+      inline void free_all_nodes(NodeAllocator& node_allocator, expression_node<T>* (&b)[N])
+      {
+         for (std::size_t i = 0; i < N; ++i)
+         {
+            free_node(node_allocator,b[i]);
+         }
+      }
+
+      template <typename NodeAllocator,
+                typename T,
+                typename Allocator,
+                template <typename, typename> class Sequence>
+      inline void free_all_nodes(NodeAllocator& node_allocator, Sequence<expression_node<T>*,Allocator>& b)
+      {
+         for (std::size_t i = 0; i < b.size(); ++i)
+         {
+            free_node(node_allocator,b[i]);
+         }
+
+         b.clear();
+      }
+
+      template <typename NodeAllocator, typename T>
+      inline void free_node(NodeAllocator& node_allocator, expression_node<T>*& node, const bool force_delete = false)
+      {
+         if (0 != node)
+         {
+            if (
+                 (is_variable_node(node) || is_string_node(node)) ||
+                 force_delete
+               )
+               return;
+
+            node_allocator.free(node);
+            node = reinterpret_cast<expression_node<T>*>(0);
+         }
+      }
+
+      template <typename T>
+      inline void destroy_node(expression_node<T>*& node)
+      {
+         delete node;
+         node = reinterpret_cast<expression_node<T>*>(0);
+      }
+
+      template <typename Type>
+      class vector_holder
+      {
+      private:
+
+         typedef Type value_type;
+         typedef value_type* value_ptr;
+         typedef const value_ptr const_value_ptr;
+
+         class vector_holder_base
+         {
+         public:
+
+            virtual ~vector_holder_base() {}
+
+            inline value_ptr operator[](const std::size_t& index) const
+            {
+               return value_at(index);
+            }
+
+            inline std::size_t size() const
+            {
+               return vector_size();
+            }
+
+            inline value_ptr data() const
+            {
+               return value_at(0);
+            }
+
+            virtual inline bool rebaseable() const
+            {
+               return false;
+            }
+
+            virtual void set_ref(value_ptr*) {}
+
+         protected:
+
+            virtual value_ptr value_at(const std::size_t&) const = 0;
+            virtual std::size_t vector_size()              const = 0;
+         };
+
+         class array_vector_impl : public vector_holder_base
+         {
+         public:
+
+            array_vector_impl(const Type* vec, const std::size_t& vec_size)
+            : vec_(vec),
+              size_(vec_size)
+            {}
+
+         protected:
+
+            value_ptr value_at(const std::size_t& index) const
+            {
+               if (index < size_)
+                  return const_cast<const_value_ptr>(vec_ + index);
+               else
+                  return const_value_ptr(0);
+            }
+
+            std::size_t vector_size() const
+            {
+               return size_;
+            }
+
+         private:
+
+            array_vector_impl operator=(const array_vector_impl&);
+
+            const Type* vec_;
+            const std::size_t size_;
+         };
+
+         template <typename Allocator,
+                   template <typename, typename> class Sequence>
+         class sequence_vector_impl : public vector_holder_base
+         {
+         public:
+
+            typedef Sequence<Type,Allocator> sequence_t;
+
+            sequence_vector_impl(sequence_t& seq)
+            : sequence_(seq)
+            {}
+
+         protected:
+
+            value_ptr value_at(const std::size_t& index) const
+            {
+               return (index < sequence_.size()) ? (&sequence_[index]) : const_value_ptr(0);
+            }
+
+            std::size_t vector_size() const
+            {
+               return sequence_.size();
+            }
+
+         private:
+
+            sequence_vector_impl operator=(const sequence_vector_impl&);
+
+            sequence_t& sequence_;
+         };
+
+         class vector_view_impl : public vector_holder_base
+         {
+         public:
+
+            typedef exprtk::vector_view<Type> vector_view_t;
+
+            vector_view_impl(vector_view_t& vec_view)
+            : vec_view_(vec_view)
+            {}
+
+            void set_ref(value_ptr* ref)
+            {
+               vec_view_.set_ref(ref);
+            }
+
+            virtual inline bool rebaseable() const
+            {
+               return true;
+            }
+
+         protected:
+
+            value_ptr value_at(const std::size_t& index) const
+            {
+               return (index < vec_view_.size()) ? (&vec_view_[index]) : const_value_ptr(0);
+            }
+
+            std::size_t vector_size() const
+            {
+               return vec_view_.size();
+            }
+
+         private:
+
+            vector_view_impl operator=(const vector_view_impl&);
+
+            vector_view_t& vec_view_;
+         };
+
+      public:
+
+         typedef typename details::vec_data_store<Type> vds_t;
+
+         vector_holder(Type* vec, const std::size_t& vec_size)
+         : vector_holder_base_(new(buffer)array_vector_impl(vec,vec_size))
+         {}
+
+         vector_holder(const vds_t& vds)
+         : vector_holder_base_(new(buffer)array_vector_impl(vds.data(),vds.size()))
+         {}
+
+         template <typename Allocator>
+         vector_holder(std::vector<Type,Allocator>& vec)
+         : vector_holder_base_(new(buffer)sequence_vector_impl<Allocator,std::vector>(vec))
+         {}
+
+         vector_holder(exprtk::vector_view<Type>& vec)
+         : vector_holder_base_(new(buffer)vector_view_impl(vec))
+         {}
+
+         inline value_ptr operator[](const std::size_t& index) const
+         {
+            return (*vector_holder_base_)[index];
+         }
+
+         inline std::size_t size() const
+         {
+            return vector_holder_base_->size();
+         }
+
+         inline value_ptr data() const
+         {
+            return vector_holder_base_->data();
+         }
+
+         void set_ref(value_ptr* ref)
+         {
+            vector_holder_base_->set_ref(ref);
+         }
+
+         bool rebaseable() const
+         {
+            return vector_holder_base_->rebaseable();
+         }
+
+      private:
+
+         mutable vector_holder_base* vector_holder_base_;
+         uchar_t buffer[64];
+      };
+
+      template <typename T>
+      class null_node : public expression_node<T>
+      {
+      public:
+
+         inline T value() const
+         {
+            return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_null;
+         }
+      };
+
+      template <typename T>
+      class null_eq_node : public expression_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+
+         null_eq_node(expression_ptr brnch, const bool equality = true)
+         : branch_(brnch),
+           branch_deletable_(branch_deletable(branch_)),
+           equality_(equality)
+         {}
+
+        ~null_eq_node()
+         {
+            if (branch_ && branch_deletable_)
+            {
+               destroy_node(branch_);
+            }
+         }
+
+         inline T value() const
+         {
+            const T v = branch_->value();
+            const bool result = details::numeric::is_nan(v);
+
+            if (result)
+               return (equality_) ? T(1) : T(0);
+            else
+               return (equality_) ? T(0) : T(1);
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_nulleq;
+         }
+
+         inline operator_type operation() const
+         {
+            return details::e_eq;
+         }
+
+         inline expression_node<T>* branch(const std::size_t&) const
+         {
+            return branch_;
+         }
+
+      private:
+
+         expression_ptr branch_;
+         const bool branch_deletable_;
+         bool equality_;
+      };
+
+      template <typename T>
+      class literal_node : public expression_node<T>
+      {
+      public:
+
+         explicit literal_node(const T& v)
+         : value_(v)
+         {}
+
+         inline T value() const
+         {
+            return value_;
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_constant;
+         }
+
+         inline expression_node<T>* branch(const std::size_t&) const
+         {
+            return reinterpret_cast<expression_node<T>*>(0);
+         }
+
+      private:
+
+         literal_node(literal_node<T>&) {}
+         literal_node<T>& operator=(literal_node<T>&) { return (*this); }
+
+         const T value_;
+      };
+
+      template <typename T>
+      struct range_pack;
+
+      template <typename T>
+      struct range_data_type;
+
+      template <typename T>
+      class range_interface
+      {
+      public:
+
+         typedef range_pack<T> range_t;
+
+         virtual ~range_interface()
+         {}
+
+         virtual range_t& range_ref() = 0;
+
+         virtual const range_t& range_ref() const = 0;
+      };
+
+      #ifndef exprtk_disable_string_capabilities
+      template <typename T>
+      class string_base_node
+      {
+      public:
+
+         typedef range_data_type<T> range_data_type_t;
+
+         virtual ~string_base_node()
+         {}
+
+         virtual std::string str () const = 0;
+
+         virtual char_cptr   base() const = 0;
+
+         virtual std::size_t size() const = 0;
+      };
+
+      template <typename T>
+      class string_literal_node : public expression_node <T>,
+                                  public string_base_node<T>,
+                                  public range_interface <T>
+      {
+      public:
+
+         typedef range_pack<T> range_t;
+
+         explicit string_literal_node(const std::string& v)
+         : value_(v)
+         {
+            rp_.n0_c = std::make_pair<bool,std::size_t>(true,0);
+            rp_.n1_c = std::make_pair<bool,std::size_t>(true,v.size() - 1);
+            rp_.cache.first  = rp_.n0_c.second;
+            rp_.cache.second = rp_.n1_c.second;
+         }
+
+         inline T value() const
+         {
+            return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_stringconst;
+         }
+
+         inline expression_node<T>* branch(const std::size_t&) const
+         {
+            return reinterpret_cast<expression_node<T>*>(0);
+         }
+
+         std::string str() const
+         {
+            return value_;
+         }
+
+         char_cptr base() const
+         {
+            return value_.data();
+         }
+
+         std::size_t size() const
+         {
+            return value_.size();
+         }
+
+         range_t& range_ref()
+         {
+            return rp_;
+         }
+
+         const range_t& range_ref() const
+         {
+            return rp_;
+         }
+
+      private:
+
+         string_literal_node(const string_literal_node<T>&);
+         string_literal_node<T>& operator=(const string_literal_node<T>&);
+
+         const std::string value_;
+         range_t rp_;
+      };
+      #endif
+
+      template <typename T>
+      class unary_node : public expression_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+
+         unary_node(const operator_type& opr,
+                    expression_ptr brnch)
+         : operation_(opr),
+           branch_(brnch),
+           branch_deletable_(branch_deletable(branch_))
+         {}
+
+        ~unary_node()
+         {
+            if (branch_ && branch_deletable_)
+            {
+               destroy_node(branch_);
+            }
+         }
+
+         inline T value() const
+         {
+            const T arg = branch_->value();
+
+            return numeric::process<T>(operation_,arg);
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_unary;
+         }
+
+         inline operator_type operation() const
+         {
+            return operation_;
+         }
+
+         inline expression_node<T>* branch(const std::size_t&) const
+         {
+            return branch_;
+         }
+
+         inline void release()
+         {
+            branch_deletable_ = false;
+         }
+
+      protected:
+
+         operator_type operation_;
+         expression_ptr branch_;
+         bool branch_deletable_;
+      };
+
+      template <typename T, std::size_t D, bool B>
+      struct construct_branch_pair
+      {
+         template <std::size_t N>
+         static inline void process(std::pair<expression_node<T>*,bool> (&)[N], expression_node<T>*)
+         {}
+      };
+
+      template <typename T, std::size_t D>
+      struct construct_branch_pair<T,D,true>
+      {
+         template <std::size_t N>
+         static inline void process(std::pair<expression_node<T>*,bool> (&branch)[N], expression_node<T>* b)
+         {
+            if (b)
+            {
+               branch[D] = std::make_pair(b,branch_deletable(b));
+            }
+         }
+      };
+
+      template <std::size_t N, typename T>
+      inline void init_branches(std::pair<expression_node<T>*,bool> (&branch)[N],
+                                expression_node<T>* b0,
+                                expression_node<T>* b1 = reinterpret_cast<expression_node<T>*>(0),
+                                expression_node<T>* b2 = reinterpret_cast<expression_node<T>*>(0),
+                                expression_node<T>* b3 = reinterpret_cast<expression_node<T>*>(0),
+                                expression_node<T>* b4 = reinterpret_cast<expression_node<T>*>(0),
+                                expression_node<T>* b5 = reinterpret_cast<expression_node<T>*>(0),
+                                expression_node<T>* b6 = reinterpret_cast<expression_node<T>*>(0),
+                                expression_node<T>* b7 = reinterpret_cast<expression_node<T>*>(0),
+                                expression_node<T>* b8 = reinterpret_cast<expression_node<T>*>(0),
+                                expression_node<T>* b9 = reinterpret_cast<expression_node<T>*>(0))
+      {
+         construct_branch_pair<T,0,(N > 0)>::process(branch,b0);
+         construct_branch_pair<T,1,(N > 1)>::process(branch,b1);
+         construct_branch_pair<T,2,(N > 2)>::process(branch,b2);
+         construct_branch_pair<T,3,(N > 3)>::process(branch,b3);
+         construct_branch_pair<T,4,(N > 4)>::process(branch,b4);
+         construct_branch_pair<T,5,(N > 5)>::process(branch,b5);
+         construct_branch_pair<T,6,(N > 6)>::process(branch,b6);
+         construct_branch_pair<T,7,(N > 7)>::process(branch,b7);
+         construct_branch_pair<T,8,(N > 8)>::process(branch,b8);
+         construct_branch_pair<T,9,(N > 9)>::process(branch,b9);
+      }
+
+      struct cleanup_branches
+      {
+         template <typename T, std::size_t N>
+         static inline void execute(std::pair<expression_node<T>*,bool> (&branch)[N])
+         {
+            for (std::size_t i = 0; i < N; ++i)
+            {
+               if (branch[i].first && branch[i].second)
+               {
+                  destroy_node(branch[i].first);
+               }
+            }
+         }
+
+         template <typename T,
+                   typename Allocator,
+                   template <typename, typename> class Sequence>
+         static inline void execute(Sequence<std::pair<expression_node<T>*,bool>,Allocator>& branch)
+         {
+            for (std::size_t i = 0; i < branch.size(); ++i)
+            {
+               if (branch[i].first && branch[i].second)
+               {
+                  destroy_node(branch[i].first);
+               }
+            }
+         }
+      };
+
+      template <typename T>
+      class binary_node : public expression_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+         typedef std::pair<expression_ptr,bool> branch_t;
+
+         binary_node(const operator_type& opr,
+                     expression_ptr branch0,
+                     expression_ptr branch1)
+         : operation_(opr)
+         {
+            init_branches<2>(branch_, branch0, branch1);
+         }
+
+        ~binary_node()
+         {
+            cleanup_branches::execute<T,2>(branch_);
+         }
+
+         inline T value() const
+         {
+            const T arg0 = branch_[0].first->value();
+            const T arg1 = branch_[1].first->value();
+
+            return numeric::process<T>(operation_,arg0,arg1);
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_binary;
+         }
+
+         inline operator_type operation()
+         {
+            return operation_;
+         }
+
+         inline expression_node<T>* branch(const std::size_t& index = 0) const
+         {
+            if (0 == index)
+               return branch_[0].first;
+            else if (1 == index)
+               return branch_[1].first;
+            else
+               return reinterpret_cast<expression_ptr>(0);
+         }
+
+      protected:
+
+         operator_type operation_;
+         branch_t branch_[2];
+      };
+
+      template <typename T, typename Operation>
+      class binary_ext_node : public expression_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+         typedef std::pair<expression_ptr,bool> branch_t;
+
+         binary_ext_node(expression_ptr branch0, expression_ptr branch1)
+         {
+            init_branches<2>(branch_, branch0, branch1);
+         }
+
+        ~binary_ext_node()
+         {
+            cleanup_branches::execute<T,2>(branch_);
+         }
+
+         inline T value() const
+         {
+            const T arg0 = branch_[0].first->value();
+            const T arg1 = branch_[1].first->value();
+
+            return Operation::process(arg0,arg1);
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_binary_ext;
+         }
+
+         inline operator_type operation()
+         {
+            return Operation::operation();
+         }
+
+         inline expression_node<T>* branch(const std::size_t& index = 0) const
+         {
+            if (0 == index)
+               return branch_[0].first;
+            else if (1 == index)
+               return branch_[1].first;
+            else
+               return reinterpret_cast<expression_ptr>(0);
+         }
+
+      protected:
+
+         branch_t branch_[2];
+      };
+
+      template <typename T>
+      class trinary_node : public expression_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+         typedef std::pair<expression_ptr,bool> branch_t;
+
+         trinary_node(const operator_type& opr,
+                      expression_ptr branch0,
+                      expression_ptr branch1,
+                      expression_ptr branch2)
+         : operation_(opr)
+         {
+            init_branches<3>(branch_, branch0, branch1, branch2);
+         }
+
+        ~trinary_node()
+         {
+            cleanup_branches::execute<T,3>(branch_);
+         }
+
+         inline T value() const
+         {
+            const T arg0 = branch_[0].first->value();
+            const T arg1 = branch_[1].first->value();
+            const T arg2 = branch_[2].first->value();
+
+            switch (operation_)
+            {
+               case e_inrange : return (arg1 < arg0) ? T(0) : ((arg1 > arg2) ? T(0) : T(1));
+
+               case e_clamp   : return (arg1 < arg0) ? arg0 : (arg1 > arg2 ? arg2 : arg1);
+
+               case e_iclamp  : if ((arg1 <= arg0) || (arg1 >= arg2))
+                                   return arg1;
+                                else
+                                   return ((T(2) * arg1  <= (arg2 + arg0)) ? arg0 : arg2);
+
+               default        : exprtk_debug(("trinary_node::value() - Error: Invalid operation\n"));
+                                return std::numeric_limits<T>::quiet_NaN();
+            }
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_trinary;
+         }
+
+      protected:
+
+         operator_type operation_;
+         branch_t branch_[3];
+      };
+
+      template <typename T>
+      class quaternary_node : public expression_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+         typedef std::pair<expression_ptr,bool> branch_t;
+
+         quaternary_node(const operator_type& opr,
+                         expression_ptr branch0,
+                         expression_ptr branch1,
+                         expression_ptr branch2,
+                         expression_ptr branch3)
+         : operation_(opr)
+         {
+            init_branches<4>(branch_, branch0, branch1, branch2, branch3);
+         }
+
+        ~quaternary_node()
+         {
+            cleanup_branches::execute<T,4>(branch_);
+         }
+
+         inline T value() const
+         {
+            return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_quaternary;
+         }
+
+      protected:
+
+         operator_type operation_;
+         branch_t branch_[4];
+      };
+
+      template <typename T>
+      class conditional_node : public expression_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+
+         conditional_node(expression_ptr test,
+                          expression_ptr consequent,
+                          expression_ptr alternative)
+         : test_(test),
+           consequent_(consequent),
+           alternative_(alternative),
+           test_deletable_(branch_deletable(test_)),
+           consequent_deletable_(branch_deletable(consequent_)),
+           alternative_deletable_(branch_deletable(alternative_))
+         {}
+
+        ~conditional_node()
+         {
+            if (test_ && test_deletable_)
+            {
+               destroy_node(test_);
+            }
+
+            if (consequent_ && consequent_deletable_ )
+            {
+               destroy_node(consequent_);
+            }
+
+            if (alternative_ && alternative_deletable_)
+            {
+               destroy_node(alternative_);
+            }
+         }
+
+         inline T value() const
+         {
+            if (is_true(test_))
+               return consequent_->value();
+            else
+               return alternative_->value();
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_conditional;
+         }
+
+      private:
+
+         expression_ptr test_;
+         expression_ptr consequent_;
+         expression_ptr alternative_;
+         const bool test_deletable_;
+         const bool consequent_deletable_;
+         const bool alternative_deletable_;
+      };
+
+      template <typename T>
+      class cons_conditional_node : public expression_node<T>
+      {
+      public:
+
+         // Consequent only conditional statement node
+         typedef expression_node<T>* expression_ptr;
+
+         cons_conditional_node(expression_ptr test,
+                               expression_ptr consequent)
+         : test_(test),
+           consequent_(consequent),
+           test_deletable_(branch_deletable(test_)),
+           consequent_deletable_(branch_deletable(consequent_))
+         {}
+
+        ~cons_conditional_node()
+         {
+            if (test_ && test_deletable_)
+            {
+               destroy_node(test_);
+            }
+
+            if (consequent_ && consequent_deletable_)
+            {
+               destroy_node(consequent_);
+            }
+         }
+
+         inline T value() const
+         {
+            if (is_true(test_))
+               return consequent_->value();
+            else
+               return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_conditional;
+         }
+
+      private:
+
+         expression_ptr test_;
+         expression_ptr consequent_;
+         const bool test_deletable_;
+         const bool consequent_deletable_;
+      };
+
+      #ifndef exprtk_disable_break_continue
+      template <typename T>
+      class break_exception
+      {
+      public:
+
+         break_exception(const T& v)
+         : value(v)
+         {}
+
+         T value;
+      };
+
+      class continue_exception
+      {};
+
+      template <typename T>
+      class break_node : public expression_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+
+         break_node(expression_ptr ret = expression_ptr(0))
+         : return_(ret),
+           return_deletable_(branch_deletable(return_))
+         {}
+
+        ~break_node()
+         {
+            if (return_deletable_)
+            {
+               destroy_node(return_);
+            }
+         }
+
+         inline T value() const
+         {
+            throw break_exception<T>(return_ ? return_->value() : std::numeric_limits<T>::quiet_NaN());
+            #ifndef _MSC_VER
+            return std::numeric_limits<T>::quiet_NaN();
+            #endif
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_break;
+         }
+
+      private:
+
+         expression_ptr return_;
+         const bool return_deletable_;
+      };
+
+      template <typename T>
+      class continue_node : public expression_node<T>
+      {
+      public:
+
+         inline T value() const
+         {
+            throw continue_exception();
+            #ifndef _MSC_VER
+            return std::numeric_limits<T>::quiet_NaN();
+            #endif
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_break;
+         }
+      };
+      #endif
+
+      template <typename T>
+      class while_loop_node : public expression_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+
+         while_loop_node(expression_ptr condition, expression_ptr loop_body)
+         : condition_(condition),
+           loop_body_(loop_body),
+           condition_deletable_(branch_deletable(condition_)),
+           loop_body_deletable_(branch_deletable(loop_body_))
+         {}
+
+        ~while_loop_node()
+         {
+            if (condition_ && condition_deletable_)
+            {
+               destroy_node(condition_);
+            }
+
+            if (loop_body_ && loop_body_deletable_)
+            {
+               destroy_node(loop_body_);
+            }
+         }
+
+         inline T value() const
+         {
+            T result = T(0);
+
+            while (is_true(condition_))
+            {
+               result = loop_body_->value();
+            }
+
+            return result;
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_while;
+         }
+
+      private:
+
+         expression_ptr condition_;
+         expression_ptr loop_body_;
+         const bool condition_deletable_;
+         const bool loop_body_deletable_;
+      };
+
+      template <typename T>
+      class repeat_until_loop_node : public expression_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+
+         repeat_until_loop_node(expression_ptr condition, expression_ptr loop_body)
+         : condition_(condition),
+           loop_body_(loop_body),
+           condition_deletable_(branch_deletable(condition_)),
+           loop_body_deletable_(branch_deletable(loop_body_))
+         {}
+
+        ~repeat_until_loop_node()
+         {
+            if (condition_ && condition_deletable_)
+            {
+               destroy_node(condition_);
+            }
+
+            if (loop_body_ && loop_body_deletable_)
+            {
+               destroy_node(loop_body_);
+            }
+         }
+
+         inline T value() const
+         {
+            T result = T(0);
+
+            do
+            {
+               result = loop_body_->value();
+            }
+            while (is_false(condition_));
+
+            return result;
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_repeat;
+         }
+
+      private:
+
+         expression_ptr condition_;
+         expression_ptr loop_body_;
+         const bool condition_deletable_;
+         const bool loop_body_deletable_;
+      };
+
+      template <typename T>
+      class for_loop_node : public expression_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+
+         for_loop_node(expression_ptr initialiser,
+                       expression_ptr condition,
+                       expression_ptr incrementor,
+                       expression_ptr loop_body)
+         : initialiser_(initialiser),
+           condition_  (condition  ),
+           incrementor_(incrementor),
+           loop_body_  (loop_body  ),
+           initialiser_deletable_(branch_deletable(initialiser_)),
+           condition_deletable_  (branch_deletable(condition_  )),
+           incrementor_deletable_(branch_deletable(incrementor_)),
+           loop_body_deletable_  (branch_deletable(loop_body_  ))
+         {}
+
+        ~for_loop_node()
+         {
+            if (initialiser_ && initialiser_deletable_)
+            {
+               destroy_node(initialiser_);
+            }
+
+            if (condition_ && condition_deletable_)
+            {
+               destroy_node(condition_);
+            }
+
+            if (incrementor_ && incrementor_deletable_)
+            {
+               destroy_node(incrementor_);
+            }
+
+            if (loop_body_ && loop_body_deletable_)
+            {
+               destroy_node(loop_body_);
+            }
+         }
+
+         inline T value() const
+         {
+            T result = T(0);
+
+            if (initialiser_)
+               initialiser_->value();
+
+            if (incrementor_)
+            {
+               while (is_true(condition_))
+               {
+                  result = loop_body_->value();
+                  incrementor_->value();
+               }
+            }
+            else
+            {
+               while (is_true(condition_))
+               {
+                  result = loop_body_->value();
+               }
+            }
+
+            return result;
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_for;
+         }
+
+      private:
+
+         expression_ptr initialiser_      ;
+         expression_ptr condition_        ;
+         expression_ptr incrementor_      ;
+         expression_ptr loop_body_        ;
+         const bool initialiser_deletable_;
+         const bool condition_deletable_  ;
+         const bool incrementor_deletable_;
+         const bool loop_body_deletable_  ;
+      };
+
+      #ifndef exprtk_disable_break_continue
+      template <typename T>
+      class while_loop_bc_node : public expression_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+
+         while_loop_bc_node(expression_ptr condition, expression_ptr loop_body)
+         : condition_(condition),
+           loop_body_(loop_body),
+           condition_deletable_(branch_deletable(condition_)),
+           loop_body_deletable_(branch_deletable(loop_body_))
+         {}
+
+        ~while_loop_bc_node()
+         {
+            if (condition_ && condition_deletable_)
+            {
+               destroy_node(condition_);
+            }
+
+            if (loop_body_ && loop_body_deletable_)
+            {
+               destroy_node(loop_body_);
+            }
+         }
+
+         inline T value() const
+         {
+            T result = T(0);
+
+            while (is_true(condition_))
+            {
+               try
+               {
+                  result = loop_body_->value();
+               }
+               catch(const break_exception<T>& e)
+               {
+                  return e.value;
+               }
+               catch(const continue_exception&)
+               {}
+            }
+
+            return result;
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_while;
+         }
+
+      private:
+
+         expression_ptr condition_;
+         expression_ptr loop_body_;
+         const bool condition_deletable_;
+         const bool loop_body_deletable_;
+      };
+
+      template <typename T>
+      class repeat_until_loop_bc_node : public expression_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+
+         repeat_until_loop_bc_node(expression_ptr condition, expression_ptr loop_body)
+         : condition_(condition),
+           loop_body_(loop_body),
+           condition_deletable_(branch_deletable(condition_)),
+           loop_body_deletable_(branch_deletable(loop_body_))
+         {}
+
+        ~repeat_until_loop_bc_node()
+         {
+            if (condition_ && condition_deletable_)
+            {
+               destroy_node(condition_);
+            }
+
+            if (loop_body_ && loop_body_deletable_)
+            {
+               destroy_node(loop_body_);
+            }
+         }
+
+         inline T value() const
+         {
+            T result = T(0);
+
+            do
+            {
+               try
+               {
+                  result = loop_body_->value();
+               }
+               catch(const break_exception<T>& e)
+               {
+                  return e.value;
+               }
+               catch(const continue_exception&)
+               {}
+            }
+            while (is_false(condition_));
+
+            return result;
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_repeat;
+         }
+
+      private:
+
+         expression_ptr condition_;
+         expression_ptr loop_body_;
+         const bool condition_deletable_;
+         const bool loop_body_deletable_;
+      };
+
+      template <typename T>
+      class for_loop_bc_node : public expression_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+
+         for_loop_bc_node(expression_ptr initialiser,
+                       expression_ptr condition,
+                       expression_ptr incrementor,
+                       expression_ptr loop_body)
+         : initialiser_(initialiser),
+           condition_  (condition  ),
+           incrementor_(incrementor),
+           loop_body_  (loop_body  ),
+           initialiser_deletable_(branch_deletable(initialiser_)),
+           condition_deletable_  (branch_deletable(condition_  )),
+           incrementor_deletable_(branch_deletable(incrementor_)),
+           loop_body_deletable_  (branch_deletable(loop_body_  ))
+         {}
+
+        ~for_loop_bc_node()
+         {
+            if (initialiser_ && initialiser_deletable_)
+            {
+               destroy_node(initialiser_);
+            }
+
+            if (condition_ && condition_deletable_)
+            {
+               destroy_node(condition_);
+            }
+
+            if (incrementor_ && incrementor_deletable_)
+            {
+               destroy_node(incrementor_);
+            }
+
+            if (loop_body_ && loop_body_deletable_)
+            {
+               destroy_node(loop_body_);
+            }
+         }
+
+         inline T value() const
+         {
+            T result = T(0);
+
+            if (initialiser_)
+               initialiser_->value();
+
+            if (incrementor_)
+            {
+               while (is_true(condition_))
+               {
+                  try
+                  {
+                     result = loop_body_->value();
+                  }
+                  catch(const break_exception<T>& e)
+                  {
+                     return e.value;
+                  }
+                  catch(const continue_exception&)
+                  {}
+
+                  incrementor_->value();
+               }
+            }
+            else
+            {
+               while (is_true(condition_))
+               {
+                  try
+                  {
+                     result = loop_body_->value();
+                  }
+                  catch(const break_exception<T>& e)
+                  {
+                     return e.value;
+                  }
+                  catch(const continue_exception&)
+                  {}
+               }
+            }
+
+            return result;
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_for;
+         }
+
+      private:
+
+         expression_ptr initialiser_;
+         expression_ptr condition_  ;
+         expression_ptr incrementor_;
+         expression_ptr loop_body_  ;
+         const bool initialiser_deletable_;
+         const bool condition_deletable_  ;
+         const bool incrementor_deletable_;
+         const bool loop_body_deletable_  ;
+      };
+      #endif
+
+      template <typename T>
+      class switch_node : public expression_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+
+         template <typename Allocator,
+                   template <typename, typename> class Sequence>
+         explicit switch_node(const Sequence<expression_ptr,Allocator>& arg_list)
+         {
+            if (1 != (arg_list.size() & 1))
+               return;
+
+            arg_list_.resize(arg_list.size());
+            delete_branch_.resize(arg_list.size());
+
+            for (std::size_t i = 0; i < arg_list.size(); ++i)
+            {
+               if (arg_list[i])
+               {
+                       arg_list_[i] = arg_list[i];
+                  delete_branch_[i] = static_cast<unsigned char>(branch_deletable(arg_list_[i]) ? 1 : 0);
+               }
+               else
+               {
+                  arg_list_.clear();
+                  delete_branch_.clear();
+                  return;
+               }
+            }
+         }
+
+        ~switch_node()
+         {
+            for (std::size_t i = 0; i < arg_list_.size(); ++i)
+            {
+               if (arg_list_[i] && delete_branch_[i])
+               {
+                  destroy_node(arg_list_[i]);
+               }
+            }
+         }
+
+         inline T value() const
+         {
+            if (!arg_list_.empty())
+            {
+               const std::size_t upper_bound = (arg_list_.size() - 1);
+
+               for (std::size_t i = 0; i < upper_bound; i += 2)
+               {
+                  expression_ptr condition  = arg_list_[i    ];
+                  expression_ptr consequent = arg_list_[i + 1];
+
+                  if (is_true(condition))
+                  {
+                     return consequent->value();
+                  }
+               }
+
+               return arg_list_[upper_bound]->value();
+            }
+            else
+               return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_switch;
+         }
+
+      protected:
+
+         std::vector<expression_ptr> arg_list_;
+         std::vector<unsigned char> delete_branch_;
+      };
+
+      template <typename T, typename Switch_N>
+      class switch_n_node : public switch_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+
+         template <typename Allocator,
+                   template <typename, typename> class Sequence>
+         explicit switch_n_node(const Sequence<expression_ptr,Allocator>& arg_list)
+         : switch_node<T>(arg_list)
+         {}
+
+         inline T value() const
+         {
+            return Switch_N::process(switch_node<T>::arg_list_);
+         }
+      };
+
+      template <typename T>
+      class multi_switch_node : public expression_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+
+         template <typename Allocator,
+                   template <typename, typename> class Sequence>
+         explicit multi_switch_node(const Sequence<expression_ptr,Allocator>& arg_list)
+         {
+            if (0 != (arg_list.size() & 1))
+               return;
+
+            arg_list_.resize(arg_list.size());
+            delete_branch_.resize(arg_list.size());
+
+            for (std::size_t i = 0; i < arg_list.size(); ++i)
+            {
+               if (arg_list[i])
+               {
+                       arg_list_[i] = arg_list[i];
+                  delete_branch_[i] = static_cast<unsigned char>(branch_deletable(arg_list_[i]) ? 1 : 0);
+               }
+               else
+               {
+                  arg_list_.clear();
+                  delete_branch_.clear();
+                  return;
+               }
+            }
+         }
+
+        ~multi_switch_node()
+         {
+            for (std::size_t i = 0; i < arg_list_.size(); ++i)
+            {
+               if (arg_list_[i] && delete_branch_[i])
+               {
+                  destroy_node(arg_list_[i]);
+               }
+            }
+         }
+
+         inline T value() const
+         {
+            T result = T(0);
+
+            if (arg_list_.empty())
+            {
+               return std::numeric_limits<T>::quiet_NaN();
+            }
+
+            const std::size_t upper_bound = (arg_list_.size() - 1);
+
+            for (std::size_t i = 0; i < upper_bound; i += 2)
+            {
+               expression_ptr condition  = arg_list_[i    ];
+               expression_ptr consequent = arg_list_[i + 1];
+
+               if (is_true(condition))
+               {
+                  result = consequent->value();
+               }
+            }
+
+            return result;
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_mswitch;
+         }
+
+      private:
+
+         std::vector<expression_ptr> arg_list_;
+         std::vector<unsigned char> delete_branch_;
+      };
+
+      template <typename T>
+      class ivariable
+      {
+      public:
+
+         virtual ~ivariable()
+         {}
+
+         virtual T& ref() = 0;
+         virtual const T& ref() const = 0;
+      };
+
+      template <typename T>
+      class variable_node : public expression_node<T>,
+                            public ivariable      <T>
+      {
+      public:
+
+         static T null_value;
+
+         explicit variable_node()
+         : value_(&null_value)
+         {}
+
+         explicit variable_node(T& v)
+         : value_(&v)
+         {}
+
+         inline bool operator <(const variable_node<T>& v) const
+         {
+            return this < (&v);
+         }
+
+         inline T value() const
+         {
+            return (*value_);
+         }
+
+         inline T& ref()
+         {
+            return (*value_);
+         }
+
+         inline const T& ref() const
+         {
+            return (*value_);
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_variable;
+         }
+
+      private:
+
+         T* value_;
+      };
+
+      template <typename T>
+      T variable_node<T>::null_value = T(std::numeric_limits<T>::quiet_NaN());
+
+      template <typename T>
+      struct range_pack
+      {
+         typedef expression_node<T>*           expression_node_ptr;
+         typedef std::pair<std::size_t,std::size_t> cached_range_t;
+
+         range_pack()
+         : n0_e (std::make_pair(false,expression_node_ptr(0))),
+           n1_e (std::make_pair(false,expression_node_ptr(0))),
+           n0_c (std::make_pair(false,0)),
+           n1_c (std::make_pair(false,0)),
+           cache(std::make_pair(0,0))
+         {}
+
+         void clear()
+         {
+            n0_e  = std::make_pair(false,expression_node_ptr(0));
+            n1_e  = std::make_pair(false,expression_node_ptr(0));
+            n0_c  = std::make_pair(false,0);
+            n1_c  = std::make_pair(false,0);
+            cache = std::make_pair(0,0);
+         }
+
+         void free()
+         {
+            if (n0_e.first && n0_e.second)
+            {
+               n0_e.first = false;
+
+               if (
+                    !is_variable_node(n0_e.second) &&
+                    !is_string_node  (n0_e.second)
+                  )
+               {
+                  destroy_node(n0_e.second);
+               }
+            }
+
+            if (n1_e.first && n1_e.second)
+            {
+               n1_e.first = false;
+
+               if (
+                    !is_variable_node(n1_e.second) &&
+                    !is_string_node  (n1_e.second)
+                  )
+               {
+                  destroy_node(n1_e.second);
+               }
+            }
+         }
+
+         bool const_range()
+         {
+           return ( n0_c.first &&  n1_c.first) &&
+                  (!n0_e.first && !n1_e.first);
+         }
+
+         bool var_range()
+         {
+           return ( n0_e.first &&  n1_e.first) &&
+                  (!n0_c.first && !n1_c.first);
+         }
+
+         bool operator() (std::size_t& r0, std::size_t& r1,
+                          const std::size_t& size = std::numeric_limits<std::size_t>::max()) const
+         {
+            if (n0_c.first)
+               r0 = n0_c.second;
+            else if (n0_e.first)
+            {
+               const T r0_value = n0_e.second->value();
+
+               if (r0_value < 0)
+                  return false;
+               else
+                  r0 = static_cast<std::size_t>(details::numeric::to_int64(r0_value));
+            }
+            else
+               return false;
+
+            if (n1_c.first)
+               r1 = n1_c.second;
+            else if (n1_e.first)
+            {
+               const T r1_value = n1_e.second->value();
+
+               if (r1_value < 0)
+                  return false;
+               else
+                  r1 = static_cast<std::size_t>(details::numeric::to_int64(r1_value));
+            }
+            else
+               return false;
+
+            if (
+                 (std::numeric_limits<std::size_t>::max() != size) &&
+                 (std::numeric_limits<std::size_t>::max() == r1  )
+               )
+            {
+               r1 = size - 1;
+            }
+
+            cache.first  = r0;
+            cache.second = r1;
+
+            return (r0 <= r1);
+         }
+
+         inline std::size_t const_size() const
+         {
+            return (n1_c.second - n0_c.second + 1);
+         }
+
+         inline std::size_t cache_size() const
+         {
+            return (cache.second - cache.first + 1);
+         }
+
+         std::pair<bool,expression_node_ptr> n0_e;
+         std::pair<bool,expression_node_ptr> n1_e;
+         std::pair<bool,std::size_t        > n0_c;
+         std::pair<bool,std::size_t        > n1_c;
+         mutable cached_range_t             cache;
+      };
+
+      template <typename T>
+      class string_base_node;
+
+      template <typename T>
+      struct range_data_type
+      {
+         typedef range_pack<T> range_t;
+         typedef string_base_node<T>* strbase_ptr_t;
+
+         range_data_type()
+         : range(0),
+           data (0),
+           size (0),
+           type_size(0),
+           str_node (0)
+         {}
+
+         range_t*      range;
+         void*         data;
+         std::size_t   size;
+         std::size_t   type_size;
+         strbase_ptr_t str_node;
+      };
+
+      template <typename T> class vector_node;
+
+      template <typename T>
+      class vector_interface
+      {
+      public:
+
+         typedef vector_node<T>*   vector_node_ptr;
+         typedef vec_data_store<T>           vds_t;
+
+         virtual ~vector_interface()
+         {}
+
+         virtual std::size_t size   () const = 0;
+
+         virtual vector_node_ptr vec() const = 0;
+
+         virtual vector_node_ptr vec()       = 0;
+
+         virtual       vds_t& vds   ()       = 0;
+
+         virtual const vds_t& vds   () const = 0;
+
+         virtual bool side_effect   () const { return false; }
+      };
+
+      template <typename T>
+      class vector_node : public expression_node <T>,
+                          public vector_interface<T>
+      {
+      public:
+
+         typedef expression_node<T>*  expression_ptr;
+         typedef vector_holder<T>    vector_holder_t;
+         typedef vector_node<T>*     vector_node_ptr;
+         typedef vec_data_store<T>             vds_t;
+
+         explicit vector_node(vector_holder_t* vh)
+         : vector_holder_(vh),
+           vds_((*vector_holder_).size(),(*vector_holder_)[0])
+         {
+            vector_holder_->set_ref(&vds_.ref());
+         }
+
+         vector_node(const vds_t& vds, vector_holder_t* vh)
+         : vector_holder_(vh),
+           vds_(vds)
+         {}
+
+         inline T value() const
+         {
+            return vds().data()[0];
+         }
+
+         vector_node_ptr vec() const
+         {
+            return const_cast<vector_node_ptr>(this);
+         }
+
+         vector_node_ptr vec()
+         {
+            return this;
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_vector;
+         }
+
+         std::size_t size() const
+         {
+            return vds().size();
+         }
+
+         vds_t& vds()
+         {
+            return vds_;
+         }
+
+         const vds_t& vds() const
+         {
+            return vds_;
+         }
+
+         inline vector_holder_t& vec_holder()
+         {
+            return (*vector_holder_);
+         }
+
+      private:
+
+         vector_holder_t* vector_holder_;
+         vds_t                      vds_;
+      };
+
+      template <typename T>
+      class vector_elem_node : public expression_node<T>,
+                               public ivariable      <T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+         typedef vector_holder<T>    vector_holder_t;
+         typedef vector_holder_t*    vector_holder_ptr;
+
+         vector_elem_node(expression_ptr index, vector_holder_ptr vec_holder)
+         : index_(index),
+           vec_holder_(vec_holder),
+           vector_base_((*vec_holder)[0]),
+           index_deletable_(branch_deletable(index_))
+         {}
+
+        ~vector_elem_node()
+         {
+            if (index_ && index_deletable_)
+            {
+               destroy_node(index_);
+            }
+         }
+
+         inline T value() const
+         {
+            return *(vector_base_ + static_cast<std::size_t>(details::numeric::to_int64(index_->value())));
+         }
+
+         inline T& ref()
+         {
+            return *(vector_base_ + static_cast<std::size_t>(details::numeric::to_int64(index_->value())));
+         }
+
+         inline const T& ref() const
+         {
+            return *(vector_base_ + static_cast<std::size_t>(details::numeric::to_int64(index_->value())));
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_vecelem;
+         }
+
+         inline vector_holder_t& vec_holder()
+         {
+            return (*vec_holder_);
+         }
+
+      private:
+
+         expression_ptr index_;
+         vector_holder_ptr vec_holder_;
+         T* vector_base_;
+         const bool index_deletable_;
+      };
+
+      template <typename T>
+      class rebasevector_elem_node : public expression_node<T>,
+                                     public ivariable      <T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+         typedef vector_holder<T>    vector_holder_t;
+         typedef vector_holder_t*    vector_holder_ptr;
+         typedef vec_data_store<T>   vds_t;
+
+         rebasevector_elem_node(expression_ptr index, vector_holder_ptr vec_holder)
+         : index_(index),
+           index_deletable_(branch_deletable(index_)),
+           vector_holder_(vec_holder),
+           vds_((*vector_holder_).size(),(*vector_holder_)[0])
+         {
+            vector_holder_->set_ref(&vds_.ref());
+         }
+
+        ~rebasevector_elem_node()
+         {
+            if (index_ && index_deletable_)
+            {
+               destroy_node(index_);
+            }
+         }
+
+         inline T value() const
+         {
+            return *(vds_.data() + static_cast<std::size_t>(details::numeric::to_int64(index_->value())));
+         }
+
+         inline T& ref()
+         {
+            return *(vds_.data() + static_cast<std::size_t>(details::numeric::to_int64(index_->value())));
+         }
+
+         inline const T& ref() const
+         {
+            return *(vds_.data() + static_cast<std::size_t>(details::numeric::to_int64(index_->value())));
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_rbvecelem;
+         }
+
+         inline vector_holder_t& vec_holder()
+         {
+            return (*vector_holder_);
+         }
+
+      private:
+
+         expression_ptr index_;
+         const bool index_deletable_;
+         vector_holder_ptr vector_holder_;
+         vds_t             vds_;
+      };
+
+      template <typename T>
+      class rebasevector_celem_node : public expression_node<T>,
+                                      public ivariable      <T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+         typedef vector_holder<T>    vector_holder_t;
+         typedef vector_holder_t*    vector_holder_ptr;
+         typedef vec_data_store<T>   vds_t;
+
+         rebasevector_celem_node(const std::size_t index, vector_holder_ptr vec_holder)
+         : index_(index),
+           vector_holder_(vec_holder),
+           vds_((*vector_holder_).size(),(*vector_holder_)[0])
+         {
+            vector_holder_->set_ref(&vds_.ref());
+         }
+
+         inline T value() const
+         {
+            return *(vds_.data() + index_);
+         }
+
+         inline T& ref()
+         {
+            return *(vds_.data() + index_);
+         }
+
+         inline const T& ref() const
+         {
+            return *(vds_.data() + index_);
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_rbveccelem;
+         }
+
+         inline vector_holder_t& vec_holder()
+         {
+            return (*vector_holder_);
+         }
+
+      private:
+
+         const std::size_t index_;
+         vector_holder_ptr vector_holder_;
+         vds_t vds_;
+      };
+
+      template <typename T>
+      class vector_assignment_node : public expression_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+
+         vector_assignment_node(T* vector_base,
+                                const std::size_t& size,
+                                const std::vector<expression_ptr>& initialiser_list,
+                                const bool single_value_initialse)
+         : vector_base_(vector_base),
+           initialiser_list_(initialiser_list),
+           size_(size),
+           single_value_initialse_(single_value_initialse)
+         {}
+
+        ~vector_assignment_node()
+         {
+            for (std::size_t i = 0; i < initialiser_list_.size(); ++i)
+            {
+               if (branch_deletable(initialiser_list_[i]))
+               {
+                  destroy_node(initialiser_list_[i]);
+               }
+            }
+         }
+
+         inline T value() const
+         {
+            if (single_value_initialse_)
+            {
+               for (std::size_t i = 0; i < size_; ++i)
+               {
+                  *(vector_base_ + i) = initialiser_list_[0]->value();
+               }
+            }
+            else
+            {
+               std::size_t il_size = initialiser_list_.size();
+
+               for (std::size_t i = 0; i < il_size; ++i)
+               {
+                  *(vector_base_ + i) = initialiser_list_[i]->value();
+               }
+
+               if (il_size < size_)
+               {
+                  for (std::size_t i = il_size; i < size_; ++i)
+                  {
+                     *(vector_base_ + i) = T(0);
+                  }
+               }
+            }
+
+            return *(vector_base_);
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_vecdefass;
+         }
+
+      private:
+
+         vector_assignment_node<T>& operator=(const vector_assignment_node<T>&);
+
+         mutable T* vector_base_;
+         std::vector<expression_ptr> initialiser_list_;
+         const std::size_t size_;
+         const bool single_value_initialse_;
+      };
+
+      template <typename T>
+      class swap_node : public expression_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+         typedef variable_node<T>*   variable_node_ptr;
+
+         swap_node(variable_node_ptr var0, variable_node_ptr var1)
+         : var0_(var0),
+           var1_(var1)
+         {}
+
+         inline T value() const
+         {
+            std::swap(var0_->ref(),var1_->ref());
+            return var1_->ref();
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_swap;
+         }
+
+      private:
+
+         variable_node_ptr var0_;
+         variable_node_ptr var1_;
+      };
+
+      template <typename T>
+      class swap_generic_node : public binary_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+         typedef ivariable<T>* ivariable_ptr;
+
+         swap_generic_node(expression_ptr var0, expression_ptr var1)
+         : binary_node<T>(details::e_swap, var0, var1),
+           var0_(dynamic_cast<ivariable_ptr>(var0)),
+           var1_(dynamic_cast<ivariable_ptr>(var1))
+         {}
+
+         inline T value() const
+         {
+            std::swap(var0_->ref(),var1_->ref());
+            return var1_->ref();
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_swap;
+         }
+
+      private:
+
+         ivariable_ptr var0_;
+         ivariable_ptr var1_;
+      };
+
+      template <typename T>
+      class swap_vecvec_node : public binary_node     <T>,
+                               public vector_interface<T>
+      {
+      public:
+
+         typedef expression_node<T>*  expression_ptr;
+         typedef vector_node<T>*     vector_node_ptr;
+         typedef vec_data_store<T>             vds_t;
+
+         swap_vecvec_node(expression_ptr branch0,
+                          expression_ptr branch1)
+         : binary_node<T>(details::e_swap, branch0, branch1),
+           vec0_node_ptr_(0),
+           vec1_node_ptr_(0),
+           vec_size_     (0),
+           initialised_  (false)
+         {
+            if (is_ivector_node(binary_node<T>::branch_[0].first))
+            {
+               vector_interface<T>* vi = reinterpret_cast<vector_interface<T>*>(0);
+
+               if (0 != (vi = dynamic_cast<vector_interface<T>*>(binary_node<T>::branch_[0].first)))
+               {
+                  vec0_node_ptr_ = vi->vec();
+                  vds()          = vi->vds();
+               }
+            }
+
+            if (is_ivector_node(binary_node<T>::branch_[1].first))
+            {
+               vector_interface<T>* vi = reinterpret_cast<vector_interface<T>*>(0);
+
+               if (0 != (vi = dynamic_cast<vector_interface<T>*>(binary_node<T>::branch_[1].first)))
+               {
+                  vec1_node_ptr_ = vi->vec();
+               }
+            }
+
+            if (vec0_node_ptr_ && vec1_node_ptr_)
+            {
+               vec_size_ = std::min(vec0_node_ptr_->vds().size(),
+                                    vec1_node_ptr_->vds().size());
+
+               initialised_ = true;
+            }
+         }
+
+         inline T value() const
+         {
+            if (initialised_)
+            {
+               binary_node<T>::branch_[0].first->value();
+               binary_node<T>::branch_[1].first->value();
+
+               T* vec0 = vec0_node_ptr_->vds().data();
+               T* vec1 = vec1_node_ptr_->vds().data();
+
+               for (std::size_t i = 0; i < vec_size_; ++i)
+               {
+                  std::swap(vec0[i],vec1[i]);
+               }
+
+               return vec1_node_ptr_->value();
+            }
+            else
+               return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         vector_node_ptr vec() const
+         {
+            return vec0_node_ptr_;
+         }
+
+         vector_node_ptr vec()
+         {
+            return vec0_node_ptr_;
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_vecvecswap;
+         }
+
+         std::size_t size() const
+         {
+            return vec_size_;
+         }
+
+         vds_t& vds()
+         {
+            return vds_;
+         }
+
+         const vds_t& vds() const
+         {
+            return vds_;
+         }
+
+      private:
+
+         vector_node<T>* vec0_node_ptr_;
+         vector_node<T>* vec1_node_ptr_;
+         std::size_t     vec_size_;
+         bool            initialised_;
+         vds_t           vds_;
+      };
+
+      #ifndef exprtk_disable_string_capabilities
+      template <typename T>
+      class stringvar_node : public expression_node <T>,
+                             public string_base_node<T>,
+                             public range_interface <T>
+      {
+      public:
+
+         typedef range_pack<T> range_t;
+
+         static std::string null_value;
+
+         explicit stringvar_node()
+         : value_(&null_value)
+         {}
+
+         explicit stringvar_node(std::string& v)
+         : value_(&v)
+         {
+            rp_.n0_c = std::make_pair<bool,std::size_t>(true,0);
+            rp_.n1_c = std::make_pair<bool,std::size_t>(true,v.size() - 1);
+            rp_.cache.first  = rp_.n0_c.second;
+            rp_.cache.second = rp_.n1_c.second;
+         }
+
+         inline bool operator <(const stringvar_node<T>& v) const
+         {
+            return this < (&v);
+         }
+
+         inline T value() const
+         {
+            rp_.n1_c.second  = (*value_).size() - 1;
+            rp_.cache.second = rp_.n1_c.second;
+
+            return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         std::string str() const
+         {
+            return ref();
+         }
+
+         char_cptr base() const
+         {
+            return &(*value_)[0];
+         }
+
+         std::size_t size() const
+         {
+            return ref().size();
+         }
+
+         std::string& ref()
+         {
+            return (*value_);
+         }
+
+         const std::string& ref() const
+         {
+            return (*value_);
+         }
+
+         range_t& range_ref()
+         {
+            return rp_;
+         }
+
+         const range_t& range_ref() const
+         {
+            return rp_;
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_stringvar;
+         }
+
+      private:
+
+         std::string* value_;
+         mutable range_t rp_;
+      };
+
+      template <typename T>
+      std::string stringvar_node<T>::null_value = std::string("");
+
+      template <typename T>
+      class string_range_node : public expression_node <T>,
+                                public string_base_node<T>,
+                                public range_interface <T>
+      {
+      public:
+
+         typedef range_pack<T> range_t;
+
+         static std::string null_value;
+
+         explicit string_range_node(std::string& v, const range_t& rp)
+         : value_(&v),
+           rp_(rp)
+         {}
+
+         virtual ~string_range_node()
+         {
+            rp_.free();
+         }
+
+         inline bool operator <(const string_range_node<T>& v) const
+         {
+            return this < (&v);
+         }
+
+         inline T value() const
+         {
+            return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         inline std::string str() const
+         {
+            return (*value_);
+         }
+
+         char_cptr base() const
+         {
+            return &(*value_)[0];
+         }
+
+         std::size_t size() const
+         {
+            return ref().size();
+         }
+
+         inline range_t range() const
+         {
+            return rp_;
+         }
+
+         inline virtual std::string& ref()
+         {
+            return (*value_);
+         }
+
+         inline virtual const std::string& ref() const
+         {
+            return (*value_);
+         }
+
+         inline range_t& range_ref()
+         {
+            return rp_;
+         }
+
+         inline const range_t& range_ref() const
+         {
+            return rp_;
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_stringvarrng;
+         }
+
+      private:
+
+         std::string* value_;
+         range_t      rp_;
+      };
+
+      template <typename T>
+      std::string string_range_node<T>::null_value = std::string("");
+
+      template <typename T>
+      class const_string_range_node : public expression_node <T>,
+                                      public string_base_node<T>,
+                                      public range_interface <T>
+      {
+      public:
+
+         typedef range_pack<T> range_t;
+
+         explicit const_string_range_node(const std::string& v, const range_t& rp)
+         : value_(v),
+           rp_(rp)
+         {}
+
+        ~const_string_range_node()
+         {
+            rp_.free();
+         }
+
+         inline T value() const
+         {
+            return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         std::string str() const
+         {
+            return value_;
+         }
+
+         char_cptr base() const
+         {
+            return value_.data();
+         }
+
+         std::size_t size() const
+         {
+            return value_.size();
+         }
+
+         range_t range() const
+         {
+            return rp_;
+         }
+
+         range_t& range_ref()
+         {
+            return rp_;
+         }
+
+         const range_t& range_ref() const
+         {
+            return rp_;
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_cstringvarrng;
+         }
+
+      private:
+
+         const_string_range_node<T>& operator=(const const_string_range_node<T>&);
+
+         const std::string value_;
+         range_t rp_;
+      };
+
+      template <typename T>
+      class generic_string_range_node : public expression_node <T>,
+                                        public string_base_node<T>,
+                                        public range_interface <T>
+      {
+      public:
+
+         typedef expression_node <T>*  expression_ptr;
+         typedef stringvar_node  <T>* strvar_node_ptr;
+         typedef string_base_node<T>*    str_base_ptr;
+         typedef range_pack      <T>          range_t;
+         typedef range_t*                   range_ptr;
+         typedef range_interface<T>          irange_t;
+         typedef irange_t*                 irange_ptr;
+
+         generic_string_range_node(expression_ptr str_branch, const range_t& brange)
+         : initialised_(false),
+           branch_(str_branch),
+           branch_deletable_(branch_deletable(branch_)),
+           str_base_ptr_ (0),
+           str_range_ptr_(0),
+           base_range_(brange)
+         {
+            range_.n0_c = std::make_pair<bool,std::size_t>(true,0);
+            range_.n1_c = std::make_pair<bool,std::size_t>(true,0);
+            range_.cache.first  = range_.n0_c.second;
+            range_.cache.second = range_.n1_c.second;
+
+            if (is_generally_string_node(branch_))
+            {
+               str_base_ptr_ = dynamic_cast<str_base_ptr>(branch_);
+
+               if (0 == str_base_ptr_)
+                  return;
+
+               str_range_ptr_ = dynamic_cast<irange_ptr>(branch_);
+
+               if (0 == str_range_ptr_)
+                  return;
+            }
+
+            initialised_ = (str_base_ptr_ && str_range_ptr_);
+         }
+
+        ~generic_string_range_node()
+         {
+            base_range_.free();
+
+            if (branch_ && branch_deletable_)
+            {
+               destroy_node(branch_);
+            }
+         }
+
+         inline T value() const
+         {
+            if (initialised_)
+            {
+               branch_->value();
+
+               std::size_t str_r0 = 0;
+               std::size_t str_r1 = 0;
+
+               std::size_t r0 = 0;
+               std::size_t r1 = 0;
+
+               range_t& range = str_range_ptr_->range_ref();
+
+               const std::size_t base_str_size = str_base_ptr_->size();
+
+               if (
+                    range      (str_r0, str_r1, base_str_size) &&
+                    base_range_(    r0,     r1, base_str_size)
+                  )
+               {
+                  const std::size_t size = (r1 - r0) + 1;
+
+                  range_.n1_c.second  = size - 1;
+                  range_.cache.second = range_.n1_c.second;
+
+                  value_.assign(str_base_ptr_->base() + str_r0 + r0, size);
+               }
+            }
+
+            return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         std::string str() const
+         {
+            return value_;
+         }
+
+         char_cptr base() const
+         {
+            return &value_[0];
+         }
+
+         std::size_t size() const
+         {
+            return value_.size();
+         }
+
+         range_t& range_ref()
+         {
+            return range_;
+         }
+
+         const range_t& range_ref() const
+         {
+            return range_;
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_strgenrange;
+         }
+
+      private:
+
+         bool                initialised_;
+         expression_ptr           branch_;
+         const bool     branch_deletable_;
+         str_base_ptr       str_base_ptr_;
+         irange_ptr        str_range_ptr_;
+         mutable range_t      base_range_;
+         mutable range_t           range_;
+         mutable std::string       value_;
+      };
+
+      template <typename T>
+      class string_concat_node : public binary_node     <T>,
+                                 public string_base_node<T>,
+                                 public range_interface <T>
+      {
+      public:
+
+         typedef expression_node <T>*  expression_ptr;
+         typedef string_base_node<T>*    str_base_ptr;
+         typedef range_pack      <T>          range_t;
+         typedef range_t*                   range_ptr;
+         typedef range_interface<T>          irange_t;
+         typedef irange_t*                 irange_ptr;
+
+         string_concat_node(const operator_type& opr,
+                            expression_ptr branch0,
+                            expression_ptr branch1)
+         : binary_node<T>(opr, branch0, branch1),
+           initialised_(false),
+           str0_base_ptr_ (0),
+           str1_base_ptr_ (0),
+           str0_range_ptr_(0),
+           str1_range_ptr_(0)
+         {
+            range_.n0_c = std::make_pair<bool,std::size_t>(true,0);
+            range_.n1_c = std::make_pair<bool,std::size_t>(true,0);
+
+            range_.cache.first  = range_.n0_c.second;
+            range_.cache.second = range_.n1_c.second;
+
+            if (is_generally_string_node(binary_node<T>::branch_[0].first))
+            {
+               str0_base_ptr_ = dynamic_cast<str_base_ptr>(binary_node<T>::branch_[0].first);
+
+               if (0 == str0_base_ptr_)
+                  return;
+
+               str0_range_ptr_ = dynamic_cast<irange_ptr>(binary_node<T>::branch_[0].first);
+
+               if (0 == str0_range_ptr_)
+                  return;
+            }
+
+            if (is_generally_string_node(binary_node<T>::branch_[1].first))
+            {
+               str1_base_ptr_ = dynamic_cast<str_base_ptr>(binary_node<T>::branch_[1].first);
+
+               if (0 == str1_base_ptr_)
+                  return;
+
+               str1_range_ptr_ = dynamic_cast<irange_ptr>(binary_node<T>::branch_[1].first);
+
+               if (0 == str1_range_ptr_)
+                  return;
+            }
+
+            initialised_ = str0_base_ptr_  &&
+                           str1_base_ptr_  &&
+                           str0_range_ptr_ &&
+                           str1_range_ptr_ ;
+         }
+
+         inline T value() const
+         {
+            if (initialised_)
+            {
+               binary_node<T>::branch_[0].first->value();
+               binary_node<T>::branch_[1].first->value();
+
+               std::size_t str0_r0 = 0;
+               std::size_t str0_r1 = 0;
+
+               std::size_t str1_r0 = 0;
+               std::size_t str1_r1 = 0;
+
+               range_t& range0 = str0_range_ptr_->range_ref();
+               range_t& range1 = str1_range_ptr_->range_ref();
+
+               if (
+                    range0(str0_r0, str0_r1, str0_base_ptr_->size()) &&
+                    range1(str1_r0, str1_r1, str1_base_ptr_->size())
+                  )
+               {
+                  const std::size_t size0 = (str0_r1 - str0_r0) + 1;
+                  const std::size_t size1 = (str1_r1 - str1_r0) + 1;
+
+                  value_.assign(str0_base_ptr_->base() + str0_r0, size0);
+                  value_.append(str1_base_ptr_->base() + str1_r0, size1);
+
+                  range_.n1_c.second  = value_.size() - 1;
+                  range_.cache.second = range_.n1_c.second;
+               }
+            }
+
+            return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         std::string str() const
+         {
+            return value_;
+         }
+
+         char_cptr base() const
+         {
+            return &value_[0];
+         }
+
+         std::size_t size() const
+         {
+            return value_.size();
+         }
+
+         range_t& range_ref()
+         {
+            return range_;
+         }
+
+         const range_t& range_ref() const
+         {
+            return range_;
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_strconcat;
+         }
+
+      private:
+
+         bool initialised_;
+         str_base_ptr str0_base_ptr_;
+         str_base_ptr str1_base_ptr_;
+         irange_ptr   str0_range_ptr_;
+         irange_ptr   str1_range_ptr_;
+         mutable range_t     range_;
+         mutable std::string value_;
+      };
+
+      template <typename T>
+      class swap_string_node : public binary_node     <T>,
+                               public string_base_node<T>,
+                               public range_interface <T>
+      {
+      public:
+
+         typedef expression_node <T>*  expression_ptr;
+         typedef stringvar_node  <T>* strvar_node_ptr;
+         typedef string_base_node<T>*    str_base_ptr;
+         typedef range_pack      <T>          range_t;
+         typedef range_t*                   range_ptr;
+         typedef range_interface<T>          irange_t;
+         typedef irange_t*                 irange_ptr;
+
+         swap_string_node(expression_ptr branch0, expression_ptr branch1)
+         : binary_node<T>(details::e_swap, branch0, branch1),
+           initialised_(false),
+           str0_node_ptr_(0),
+           str1_node_ptr_(0)
+         {
+            if (is_string_node(binary_node<T>::branch_[0].first))
+            {
+               str0_node_ptr_ = static_cast<strvar_node_ptr>(binary_node<T>::branch_[0].first);
+            }
+
+            if (is_string_node(binary_node<T>::branch_[1].first))
+            {
+               str1_node_ptr_ = static_cast<strvar_node_ptr>(binary_node<T>::branch_[1].first);
+            }
+
+            initialised_ = (str0_node_ptr_ && str1_node_ptr_);
+         }
+
+         inline T value() const
+         {
+            if (initialised_)
+            {
+               binary_node<T>::branch_[0].first->value();
+               binary_node<T>::branch_[1].first->value();
+
+               std::swap(str0_node_ptr_->ref(), str1_node_ptr_->ref());
+            }
+
+            return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         std::string str() const
+         {
+            return str0_node_ptr_->str();
+         }
+
+         char_cptr base() const
+         {
+           return str0_node_ptr_->base();
+         }
+
+         std::size_t size() const
+         {
+            return str0_node_ptr_->size();
+         }
+
+         range_t& range_ref()
+         {
+            return str0_node_ptr_->range_ref();
+         }
+
+         const range_t& range_ref() const
+         {
+            return str0_node_ptr_->range_ref();
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_strswap;
+         }
+
+      private:
+
+         bool initialised_;
+         strvar_node_ptr str0_node_ptr_;
+         strvar_node_ptr str1_node_ptr_;
+      };
+
+      template <typename T>
+      class swap_genstrings_node : public binary_node<T>
+      {
+      public:
+
+         typedef expression_node <T>* expression_ptr;
+         typedef string_base_node<T>*   str_base_ptr;
+         typedef range_pack      <T>         range_t;
+         typedef range_t*                  range_ptr;
+         typedef range_interface<T>         irange_t;
+         typedef irange_t*                irange_ptr;
+
+         swap_genstrings_node(expression_ptr branch0,
+                              expression_ptr branch1)
+         : binary_node<T>(details::e_default, branch0, branch1),
+           str0_base_ptr_ (0),
+           str1_base_ptr_ (0),
+           str0_range_ptr_(0),
+           str1_range_ptr_(0),
+           initialised_(false)
+         {
+            if (is_generally_string_node(binary_node<T>::branch_[0].first))
+            {
+               str0_base_ptr_ = dynamic_cast<str_base_ptr>(binary_node<T>::branch_[0].first);
+
+               if (0 == str0_base_ptr_)
+                  return;
+
+               irange_ptr range = dynamic_cast<irange_ptr>(binary_node<T>::branch_[0].first);
+
+               if (0 == range)
+                  return;
+
+               str0_range_ptr_ = &(range->range_ref());
+            }
+
+            if (is_generally_string_node(binary_node<T>::branch_[1].first))
+            {
+               str1_base_ptr_ = dynamic_cast<str_base_ptr>(binary_node<T>::branch_[1].first);
+
+               if (0 == str1_base_ptr_)
+                  return;
+
+               irange_ptr range = dynamic_cast<irange_ptr>(binary_node<T>::branch_[1].first);
+
+               if (0 == range)
+                  return;
+
+               str1_range_ptr_ = &(range->range_ref());
+            }
+
+            initialised_ = str0_base_ptr_  &&
+                           str1_base_ptr_  &&
+                           str0_range_ptr_ &&
+                           str1_range_ptr_ ;
+         }
+
+         inline T value() const
+         {
+            if (initialised_)
+            {
+               binary_node<T>::branch_[0].first->value();
+               binary_node<T>::branch_[1].first->value();
+
+               std::size_t str0_r0 = 0;
+               std::size_t str0_r1 = 0;
+
+               std::size_t str1_r0 = 0;
+               std::size_t str1_r1 = 0;
+
+               range_t& range0 = (*str0_range_ptr_);
+               range_t& range1 = (*str1_range_ptr_);
+
+               if (
+                    range0(str0_r0, str0_r1, str0_base_ptr_->size()) &&
+                    range1(str1_r0, str1_r1, str1_base_ptr_->size())
+                  )
+               {
+                  const std::size_t size0    = range0.cache_size();
+                  const std::size_t size1    = range1.cache_size();
+                  const std::size_t max_size = std::min(size0,size1);
+
+                  char_ptr s0 = const_cast<char_ptr>(str0_base_ptr_->base() + str0_r0);
+                  char_ptr s1 = const_cast<char_ptr>(str1_base_ptr_->base() + str1_r0);
+
+                  loop_unroll::details lud(max_size);
+                  char_cptr upper_bound = s0 + lud.upper_bound;
+
+                  while (s0 < upper_bound)
+                  {
+                     #define exprtk_loop(N)   \
+                     std::swap(s0[N], s1[N]); \
+
+                     exprtk_loop( 0) exprtk_loop( 1)
+                     exprtk_loop( 2) exprtk_loop( 3)
+                     #ifndef exprtk_disable_superscalar_unroll
+                     exprtk_loop( 4) exprtk_loop( 5)
+                     exprtk_loop( 6) exprtk_loop( 7)
+                     exprtk_loop( 8) exprtk_loop( 9)
+                     exprtk_loop(10) exprtk_loop(11)
+                     exprtk_loop(12) exprtk_loop(13)
+                     exprtk_loop(14) exprtk_loop(15)
+                     #endif
+
+                     s0 += lud.batch_size;
+                     s1 += lud.batch_size;
+                  }
+
+                  int i = 0;
+
+                  exprtk_disable_fallthrough_begin
+                  switch (lud.remainder)
+                  {
+                     #define case_stmt(N)                       \
+                     case N : { std::swap(s0[i], s1[i]); ++i; } \
+
+                     #ifndef exprtk_disable_superscalar_unroll
+                     case_stmt(15) case_stmt(14)
+                     case_stmt(13) case_stmt(12)
+                     case_stmt(11) case_stmt(10)
+                     case_stmt( 9) case_stmt( 8)
+                     case_stmt( 7) case_stmt( 6)
+                     case_stmt( 5) case_stmt( 4)
+                     #endif
+                     case_stmt( 3) case_stmt( 2)
+                     case_stmt( 1)
+                  }
+                  exprtk_disable_fallthrough_end
+
+                  #undef exprtk_loop
+                  #undef case_stmt
+               }
+            }
+
+            return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_strswap;
+         }
+
+      private:
+
+         swap_genstrings_node(swap_genstrings_node<T>&);
+         swap_genstrings_node<T>& operator=(swap_genstrings_node<T>&);
+
+         str_base_ptr str0_base_ptr_;
+         str_base_ptr str1_base_ptr_;
+         range_ptr    str0_range_ptr_;
+         range_ptr    str1_range_ptr_;
+         bool         initialised_;
+      };
+
+      template <typename T>
+      class stringvar_size_node : public expression_node<T>
+      {
+      public:
+
+         static std::string null_value;
+
+         explicit stringvar_size_node()
+         : value_(&null_value)
+         {}
+
+         explicit stringvar_size_node(std::string& v)
+         : value_(&v)
+         {}
+
+         inline T value() const
+         {
+            return T((*value_).size());
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_stringvarsize;
+         }
+
+      private:
+
+         std::string* value_;
+      };
+
+      template <typename T>
+      std::string stringvar_size_node<T>::null_value = std::string("");
+
+      template <typename T>
+      class string_size_node : public expression_node<T>
+      {
+      public:
+
+         typedef expression_node <T>* expression_ptr;
+         typedef string_base_node<T>*   str_base_ptr;
+
+         explicit string_size_node(expression_ptr brnch)
+         : branch_(brnch),
+           branch_deletable_(branch_deletable(branch_)),
+           str_base_ptr_(0)
+         {
+            if (is_generally_string_node(branch_))
+            {
+               str_base_ptr_ = dynamic_cast<str_base_ptr>(branch_);
+
+               if (0 == str_base_ptr_)
+                  return;
+            }
+         }
+
+        ~string_size_node()
+         {
+            if (branch_ && branch_deletable_)
+            {
+               destroy_node(branch_);
+            }
+         }
+
+         inline T value() const
+         {
+            T result = std::numeric_limits<T>::quiet_NaN();
+
+            if (str_base_ptr_)
+            {
+               branch_->value();
+               result = T(str_base_ptr_->size());
+            }
+
+            return result;
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_stringsize;
+         }
+
+      private:
+
+         expression_ptr           branch_;
+         const bool     branch_deletable_;
+         str_base_ptr       str_base_ptr_;
+      };
+
+      struct asn_assignment
+      {
+         static inline void execute(std::string& s, char_cptr data, const std::size_t size)
+         { s.assign(data,size); }
+      };
+
+      struct asn_addassignment
+      {
+         static inline void execute(std::string& s, char_cptr data, const std::size_t size)
+         { s.append(data,size); }
+      };
+
+      template <typename T, typename AssignmentProcess = asn_assignment>
+      class assignment_string_node : public binary_node     <T>,
+                                     public string_base_node<T>,
+                                     public range_interface <T>
+      {
+      public:
+
+         typedef expression_node <T>*  expression_ptr;
+         typedef stringvar_node  <T>* strvar_node_ptr;
+         typedef string_base_node<T>*    str_base_ptr;
+         typedef range_pack      <T>          range_t;
+         typedef range_t*                   range_ptr;
+         typedef range_interface<T>          irange_t;
+         typedef irange_t*                 irange_ptr;
+
+         assignment_string_node(const operator_type& opr,
+                                expression_ptr branch0,
+                                expression_ptr branch1)
+         : binary_node<T>(opr, branch0, branch1),
+           initialised_(false),
+           str0_base_ptr_ (0),
+           str1_base_ptr_ (0),
+           str0_node_ptr_ (0),
+           str1_range_ptr_(0)
+         {
+            if (is_string_node(binary_node<T>::branch_[0].first))
+            {
+               str0_node_ptr_ = static_cast<strvar_node_ptr>(binary_node<T>::branch_[0].first);
+
+               str0_base_ptr_ = dynamic_cast<str_base_ptr>(binary_node<T>::branch_[0].first);
+            }
+
+            if (is_generally_string_node(binary_node<T>::branch_[1].first))
+            {
+               str1_base_ptr_ = dynamic_cast<str_base_ptr>(binary_node<T>::branch_[1].first);
+
+               if (0 == str1_base_ptr_)
+                  return;
+
+               irange_ptr range = dynamic_cast<irange_ptr>(binary_node<T>::branch_[1].first);
+
+               if (0 == range)
+                  return;
+
+               str1_range_ptr_ = &(range->range_ref());
+            }
+
+            initialised_ = str0_base_ptr_  &&
+                           str1_base_ptr_  &&
+                           str0_node_ptr_  &&
+                           str1_range_ptr_ ;
+         }
+
+         inline T value() const
+         {
+            if (initialised_)
+            {
+               binary_node<T>::branch_[1].first->value();
+
+               std::size_t r0 = 0;
+               std::size_t r1 = 0;
+
+               range_t& range = (*str1_range_ptr_);
+
+               if (range(r0, r1, str1_base_ptr_->size()))
+               {
+                  AssignmentProcess::execute(str0_node_ptr_->ref(),
+                                             str1_base_ptr_->base() + r0,
+                                             (r1 - r0) + 1);
+
+                  binary_node<T>::branch_[0].first->value();
+               }
+            }
+
+            return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         std::string str() const
+         {
+            return str0_node_ptr_->str();
+         }
+
+         char_cptr base() const
+         {
+           return str0_node_ptr_->base();
+         }
+
+         std::size_t size() const
+         {
+            return str0_node_ptr_->size();
+         }
+
+         range_t& range_ref()
+         {
+            return str0_node_ptr_->range_ref();
+         }
+
+         const range_t& range_ref() const
+         {
+            return str0_node_ptr_->range_ref();
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_strass;
+         }
+
+      private:
+
+         bool            initialised_;
+         str_base_ptr    str0_base_ptr_;
+         str_base_ptr    str1_base_ptr_;
+         strvar_node_ptr str0_node_ptr_;
+         range_ptr       str1_range_ptr_;
+      };
+
+      template <typename T, typename AssignmentProcess = asn_assignment>
+      class assignment_string_range_node : public binary_node     <T>,
+                                           public string_base_node<T>,
+                                           public range_interface <T>
+      {
+      public:
+
+         typedef expression_node <T>*  expression_ptr;
+         typedef stringvar_node  <T>* strvar_node_ptr;
+         typedef string_base_node<T>*    str_base_ptr;
+         typedef range_pack      <T>          range_t;
+         typedef range_t*                   range_ptr;
+         typedef range_interface<T>          irange_t;
+         typedef irange_t*                 irange_ptr;
+
+         assignment_string_range_node(const operator_type& opr,
+                                      expression_ptr branch0,
+                                      expression_ptr branch1)
+         : binary_node<T>(opr, branch0, branch1),
+           initialised_(false),
+           str0_base_ptr_ (0),
+           str1_base_ptr_ (0),
+           str0_node_ptr_ (0),
+           str0_range_ptr_(0),
+           str1_range_ptr_(0)
+         {
+            if (is_string_range_node(binary_node<T>::branch_[0].first))
+            {
+               str0_node_ptr_ = static_cast<strvar_node_ptr>(binary_node<T>::branch_[0].first);
+
+               str0_base_ptr_ = dynamic_cast<str_base_ptr>(binary_node<T>::branch_[0].first);
+
+               irange_ptr range = dynamic_cast<irange_ptr>(binary_node<T>::branch_[0].first);
+
+               if (0 == range)
+                  return;
+
+               str0_range_ptr_ = &(range->range_ref());
+            }
+
+            if (is_generally_string_node(binary_node<T>::branch_[1].first))
+            {
+               str1_base_ptr_ = dynamic_cast<str_base_ptr>(binary_node<T>::branch_[1].first);
+
+               if (0 == str1_base_ptr_)
+                  return;
+
+               irange_ptr range = dynamic_cast<irange_ptr>(binary_node<T>::branch_[1].first);
+
+               if (0 == range)
+                  return;
+
+               str1_range_ptr_ = &(range->range_ref());
+            }
+
+            initialised_ = str0_base_ptr_  &&
+                           str1_base_ptr_  &&
+                           str0_node_ptr_  &&
+                           str0_range_ptr_ &&
+                           str1_range_ptr_ ;
+         }
+
+         inline T value() const
+         {
+            if (initialised_)
+            {
+               binary_node<T>::branch_[0].first->value();
+               binary_node<T>::branch_[1].first->value();
+
+               std::size_t s0_r0 = 0;
+               std::size_t s0_r1 = 0;
+
+               std::size_t s1_r0 = 0;
+               std::size_t s1_r1 = 0;
+
+               range_t& range0 = (*str0_range_ptr_);
+               range_t& range1 = (*str1_range_ptr_);
+
+               if (
+                    range0(s0_r0, s0_r1, str0_base_ptr_->size()) &&
+                    range1(s1_r0, s1_r1, str1_base_ptr_->size())
+                  )
+               {
+                  std::size_t size = std::min((s0_r1 - s0_r0), (s1_r1 - s1_r0)) + 1;
+
+                  std::copy(str1_base_ptr_->base() + s1_r0,
+                            str1_base_ptr_->base() + s1_r0 + size,
+                            const_cast<char_ptr>(base() + s0_r0));
+               }
+            }
+
+            return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         std::string str() const
+         {
+            return str0_node_ptr_->str();
+         }
+
+         char_cptr base() const
+         {
+           return str0_node_ptr_->base();
+         }
+
+         std::size_t size() const
+         {
+            return str0_node_ptr_->size();
+         }
+
+         range_t& range_ref()
+         {
+            return str0_node_ptr_->range_ref();
+         }
+
+         const range_t& range_ref() const
+         {
+            return str0_node_ptr_->range_ref();
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_strass;
+         }
+
+      private:
+
+         bool            initialised_;
+         str_base_ptr    str0_base_ptr_;
+         str_base_ptr    str1_base_ptr_;
+         strvar_node_ptr str0_node_ptr_;
+         range_ptr       str0_range_ptr_;
+         range_ptr       str1_range_ptr_;
+      };
+
+      template <typename T>
+      class conditional_string_node : public trinary_node    <T>,
+                                      public string_base_node<T>,
+                                      public range_interface <T>
+      {
+      public:
+
+         typedef expression_node <T>* expression_ptr;
+         typedef string_base_node<T>*   str_base_ptr;
+         typedef range_pack      <T>         range_t;
+         typedef range_t*                  range_ptr;
+         typedef range_interface<T>         irange_t;
+         typedef irange_t*                irange_ptr;
+
+         conditional_string_node(expression_ptr test,
+                                 expression_ptr consequent,
+                                 expression_ptr alternative)
+         : trinary_node<T>(details::e_default,consequent,alternative,test),
+           initialised_(false),
+           str0_base_ptr_ (0),
+           str1_base_ptr_ (0),
+           str0_range_ptr_(0),
+           str1_range_ptr_(0),
+           test_              (test),
+           consequent_  (consequent),
+           alternative_(alternative)
+         {
+            range_.n0_c = std::make_pair<bool,std::size_t>(true,0);
+            range_.n1_c = std::make_pair<bool,std::size_t>(true,0);
+
+            range_.cache.first  = range_.n0_c.second;
+            range_.cache.second = range_.n1_c.second;
+
+            if (is_generally_string_node(trinary_node<T>::branch_[0].first))
+            {
+               str0_base_ptr_ = dynamic_cast<str_base_ptr>(trinary_node<T>::branch_[0].first);
+
+               if (0 == str0_base_ptr_)
+                  return;
+
+               str0_range_ptr_ = dynamic_cast<irange_ptr>(trinary_node<T>::branch_[0].first);
+
+               if (0 == str0_range_ptr_)
+                  return;
+            }
+
+            if (is_generally_string_node(trinary_node<T>::branch_[1].first))
+            {
+               str1_base_ptr_ = dynamic_cast<str_base_ptr>(trinary_node<T>::branch_[1].first);
+
+               if (0 == str1_base_ptr_)
+                  return;
+
+               str1_range_ptr_ = dynamic_cast<irange_ptr>(trinary_node<T>::branch_[1].first);
+
+               if (0 == str1_range_ptr_)
+                  return;
+            }
+
+            initialised_ = str0_base_ptr_  &&
+                           str1_base_ptr_  &&
+                           str0_range_ptr_ &&
+                           str1_range_ptr_ ;
+
+         }
+
+         inline T value() const
+         {
+            if (initialised_)
+            {
+               std::size_t r0 = 0;
+               std::size_t r1 = 0;
+
+               if (is_true(test_))
+               {
+                  consequent_->value();
+
+                  range_t& range = str0_range_ptr_->range_ref();
+
+                  if (range(r0, r1, str0_base_ptr_->size()))
+                  {
+                     const std::size_t size = (r1 - r0) + 1;
+
+                     value_.assign(str0_base_ptr_->base() + r0, size);
+
+                     range_.n1_c.second  = value_.size() - 1;
+                     range_.cache.second = range_.n1_c.second;
+
+                     return T(1);
+                  }
+               }
+               else
+               {
+                  alternative_->value();
+
+                  range_t& range = str1_range_ptr_->range_ref();
+
+                  if (range(r0, r1, str1_base_ptr_->size()))
+                  {
+                     const std::size_t size = (r1 - r0) + 1;
+
+                     value_.assign(str1_base_ptr_->base() + r0, size);
+
+                     range_.n1_c.second  = value_.size() - 1;
+                     range_.cache.second = range_.n1_c.second;
+
+                     return T(0);
+                  }
+               }
+            }
+
+            return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         std::string str() const
+         {
+            return value_;
+         }
+
+         char_cptr base() const
+         {
+            return &value_[0];
+         }
+
+         std::size_t size() const
+         {
+            return value_.size();
+         }
+
+         range_t& range_ref()
+         {
+            return range_;
+         }
+
+         const range_t& range_ref() const
+         {
+            return range_;
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_strcondition;
+         }
+
+      private:
+
+         bool initialised_;
+         str_base_ptr str0_base_ptr_;
+         str_base_ptr str1_base_ptr_;
+         irange_ptr   str0_range_ptr_;
+         irange_ptr   str1_range_ptr_;
+         mutable range_t     range_;
+         mutable std::string value_;
+
+         expression_ptr test_;
+         expression_ptr consequent_;
+         expression_ptr alternative_;
+      };
+
+      template <typename T>
+      class cons_conditional_str_node : public binary_node     <T>,
+                                        public string_base_node<T>,
+                                        public range_interface <T>
+      {
+      public:
+
+         typedef expression_node <T>* expression_ptr;
+         typedef string_base_node<T>*   str_base_ptr;
+         typedef range_pack      <T>         range_t;
+         typedef range_t*                  range_ptr;
+         typedef range_interface<T>         irange_t;
+         typedef irange_t*                irange_ptr;
+
+         cons_conditional_str_node(expression_ptr test,
+                                   expression_ptr consequent)
+         : binary_node<T>(details::e_default, consequent, test),
+           initialised_(false),
+           str0_base_ptr_ (0),
+           str0_range_ptr_(0),
+           test_      (test),
+           consequent_(consequent)
+         {
+            range_.n0_c = std::make_pair<bool,std::size_t>(true,0);
+            range_.n1_c = std::make_pair<bool,std::size_t>(true,0);
+
+            range_.cache.first  = range_.n0_c.second;
+            range_.cache.second = range_.n1_c.second;
+
+            if (is_generally_string_node(binary_node<T>::branch_[0].first))
+            {
+               str0_base_ptr_ = dynamic_cast<str_base_ptr>(binary_node<T>::branch_[0].first);
+
+               if (0 == str0_base_ptr_)
+                  return;
+
+               str0_range_ptr_ = dynamic_cast<irange_ptr>(binary_node<T>::branch_[0].first);
+
+               if (0 == str0_range_ptr_)
+                  return;
+            }
+
+            initialised_ = str0_base_ptr_ && str0_range_ptr_ ;
+         }
+
+         inline T value() const
+         {
+            if (initialised_)
+            {
+               if (is_true(test_))
+               {
+                  consequent_->value();
+
+                  range_t& range = str0_range_ptr_->range_ref();
+
+                  std::size_t r0 = 0;
+                  std::size_t r1 = 0;
+
+                  if (range(r0, r1, str0_base_ptr_->size()))
+                  {
+                     const std::size_t size = (r1 - r0) + 1;
+
+                     value_.assign(str0_base_ptr_->base() + r0, size);
+
+                     range_.n1_c.second  = value_.size() - 1;
+                     range_.cache.second = range_.n1_c.second;
+
+                     return T(1);
+                  }
+               }
+            }
+
+            return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         std::string str() const
+         {
+            return value_;
+         }
+
+         char_cptr base() const
+         {
+            return &value_[0];
+         }
+
+         std::size_t size() const
+         {
+            return value_.size();
+         }
+
+         range_t& range_ref()
+         {
+            return range_;
+         }
+
+         const range_t& range_ref() const
+         {
+            return range_;
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_strccondition;
+         }
+
+      private:
+
+         bool initialised_;
+         str_base_ptr str0_base_ptr_;
+         irange_ptr   str0_range_ptr_;
+         mutable range_t     range_;
+         mutable std::string value_;
+
+         expression_ptr test_;
+         expression_ptr consequent_;
+      };
+
+      template <typename T, typename VarArgFunction>
+      class str_vararg_node  : public expression_node <T>,
+                               public string_base_node<T>,
+                               public range_interface <T>
+      {
+      public:
+
+         typedef expression_node <T>*  expression_ptr;
+         typedef string_base_node<T>*    str_base_ptr;
+         typedef range_pack      <T>          range_t;
+         typedef range_t*                   range_ptr;
+         typedef range_interface<T>          irange_t;
+         typedef irange_t*                 irange_ptr;
+
+         template <typename Allocator,
+                   template <typename, typename> class Sequence>
+         explicit str_vararg_node(const Sequence<expression_ptr,Allocator>& arg_list)
+         : final_node_(arg_list.back()),
+           final_deletable_(branch_deletable(final_node_)),
+           initialised_(false),
+           str_base_ptr_ (0),
+           str_range_ptr_(0)
+         {
+            if (0 == final_node_)
+               return;
+            else if (!is_generally_string_node(final_node_))
+               return;
+
+            str_base_ptr_ = dynamic_cast<str_base_ptr>(final_node_);
+
+            if (0 == str_base_ptr_)
+               return;
+
+            str_range_ptr_ = dynamic_cast<irange_ptr>(final_node_);
+
+            if (0 == str_range_ptr_)
+               return;
+
+            initialised_ = str_base_ptr_  && str_range_ptr_;
+
+            if (arg_list.size() > 1)
+            {
+               const std::size_t arg_list_size = arg_list.size() - 1;
+
+               arg_list_.resize(arg_list_size);
+               delete_branch_.resize(arg_list_size);
+
+               for (std::size_t i = 0; i < arg_list_size; ++i)
+               {
+                  if (arg_list[i])
+                  {
+                          arg_list_[i] = arg_list[i];
+                     delete_branch_[i] = static_cast<unsigned char>(branch_deletable(arg_list_[i]) ? 1 : 0);
+                  }
+                  else
+                  {
+                     arg_list_     .clear();
+                     delete_branch_.clear();
+                     return;
+                  }
+               }
+            }
+         }
+
+        ~str_vararg_node()
+         {
+            if (final_node_ && final_deletable_)
+            {
+               destroy_node(final_node_);
+            }
+
+            for (std::size_t i = 0; i < arg_list_.size(); ++i)
+            {
+               if (arg_list_[i] && delete_branch_[i])
+               {
+                  destroy_node(arg_list_[i]);
+               }
+            }
+         }
+
+         inline T value() const
+         {
+            if (!arg_list_.empty())
+            {
+               VarArgFunction::process(arg_list_);
+            }
+
+            final_node_->value();
+
+            return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         std::string str() const
+         {
+            return str_base_ptr_->str();
+         }
+
+         char_cptr base() const
+         {
+            return str_base_ptr_->base();
+         }
+
+         std::size_t size() const
+         {
+            return str_base_ptr_->size();
+         }
+
+         range_t& range_ref()
+         {
+            return str_range_ptr_->range_ref();
+         }
+
+         const range_t& range_ref() const
+         {
+            return str_range_ptr_->range_ref();
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_stringvararg;
+         }
+
+      private:
+
+         expression_ptr final_node_;
+         bool           final_deletable_;
+         bool           initialised_;
+         str_base_ptr   str_base_ptr_;
+         irange_ptr     str_range_ptr_;
+         std::vector<expression_ptr> arg_list_;
+         std::vector<unsigned char> delete_branch_;
+      };
+      #endif
+
+      template <typename T, std::size_t N>
+      inline T axn(T a, T x)
+      {
+         // a*x^n
+         return a * exprtk::details::numeric::fast_exp<T,N>::result(x);
+      }
+
+      template <typename T, std::size_t N>
+      inline T axnb(T a, T x, T b)
+      {
+         // a*x^n+b
+         return a * exprtk::details::numeric::fast_exp<T,N>::result(x) + b;
+      }
+
+      template <typename T>
+      struct sf_base
+      {
+         typedef typename details::functor_t<T>::Type Type;
+         typedef typename details::functor_t<T> functor_t;
+         typedef typename functor_t::qfunc_t quaternary_functor_t;
+         typedef typename functor_t::tfunc_t    trinary_functor_t;
+         typedef typename functor_t::bfunc_t     binary_functor_t;
+         typedef typename functor_t::ufunc_t      unary_functor_t;
+      };
+
+      #define define_sfop3(NN,OP0,OP1)                   \
+      template <typename T>                              \
+      struct sf##NN##_op : public sf_base<T>             \
+      {                                                  \
+         typedef typename sf_base<T>::Type const Type;   \
+         static inline T process(Type x, Type y, Type z) \
+         {                                               \
+            return (OP0);                                \
+         }                                               \
+         static inline std::string id()                  \
+         {                                               \
+            return OP1;                                  \
+         }                                               \
+      };                                                 \
+
+      define_sfop3(00,(x + y) / z       ,"(t+t)/t")
+      define_sfop3(01,(x + y) * z       ,"(t+t)*t")
+      define_sfop3(02,(x + y) - z       ,"(t+t)-t")
+      define_sfop3(03,(x + y) + z       ,"(t+t)+t")
+      define_sfop3(04,(x - y) + z       ,"(t-t)+t")
+      define_sfop3(05,(x - y) / z       ,"(t-t)/t")
+      define_sfop3(06,(x - y) * z       ,"(t-t)*t")
+      define_sfop3(07,(x * y) + z       ,"(t*t)+t")
+      define_sfop3(08,(x * y) - z       ,"(t*t)-t")
+      define_sfop3(09,(x * y) / z       ,"(t*t)/t")
+      define_sfop3(10,(x * y) * z       ,"(t*t)*t")
+      define_sfop3(11,(x / y) + z       ,"(t/t)+t")
+      define_sfop3(12,(x / y) - z       ,"(t/t)-t")
+      define_sfop3(13,(x / y) / z       ,"(t/t)/t")
+      define_sfop3(14,(x / y) * z       ,"(t/t)*t")
+      define_sfop3(15,x / (y + z)       ,"t/(t+t)")
+      define_sfop3(16,x / (y - z)       ,"t/(t-t)")
+      define_sfop3(17,x / (y * z)       ,"t/(t*t)")
+      define_sfop3(18,x / (y / z)       ,"t/(t/t)")
+      define_sfop3(19,x * (y + z)       ,"t*(t+t)")
+      define_sfop3(20,x * (y - z)       ,"t*(t-t)")
+      define_sfop3(21,x * (y * z)       ,"t*(t*t)")
+      define_sfop3(22,x * (y / z)       ,"t*(t/t)")
+      define_sfop3(23,x - (y + z)       ,"t-(t+t)")
+      define_sfop3(24,x - (y - z)       ,"t-(t-t)")
+      define_sfop3(25,x - (y / z)       ,"t-(t/t)")
+      define_sfop3(26,x - (y * z)       ,"t-(t*t)")
+      define_sfop3(27,x + (y * z)       ,"t+(t*t)")
+      define_sfop3(28,x + (y / z)       ,"t+(t/t)")
+      define_sfop3(29,x + (y + z)       ,"t+(t+t)")
+      define_sfop3(30,x + (y - z)       ,"t+(t-t)")
+      define_sfop3(31,(axnb<T,2>(x,y,z)),"       ")
+      define_sfop3(32,(axnb<T,3>(x,y,z)),"       ")
+      define_sfop3(33,(axnb<T,4>(x,y,z)),"       ")
+      define_sfop3(34,(axnb<T,5>(x,y,z)),"       ")
+      define_sfop3(35,(axnb<T,6>(x,y,z)),"       ")
+      define_sfop3(36,(axnb<T,7>(x,y,z)),"       ")
+      define_sfop3(37,(axnb<T,8>(x,y,z)),"       ")
+      define_sfop3(38,(axnb<T,9>(x,y,z)),"       ")
+      define_sfop3(39,x * numeric::log(y)   + z,"")
+      define_sfop3(40,x * numeric::log(y)   - z,"")
+      define_sfop3(41,x * numeric::log10(y) + z,"")
+      define_sfop3(42,x * numeric::log10(y) - z,"")
+      define_sfop3(43,x * numeric::sin(y) + z  ,"")
+      define_sfop3(44,x * numeric::sin(y) - z  ,"")
+      define_sfop3(45,x * numeric::cos(y) + z  ,"")
+      define_sfop3(46,x * numeric::cos(y) - z  ,"")
+      define_sfop3(47,details::is_true(x) ? y : z,"")
+
+      #define define_sfop4(NN,OP0,OP1)                           \
+      template <typename T>                                      \
+      struct sf##NN##_op : public sf_base<T>                     \
+      {                                                          \
+         typedef typename sf_base<T>::Type const Type;           \
+         static inline T process(Type x, Type y, Type z, Type w) \
+         {                                                       \
+            return (OP0);                                        \
+         }                                                       \
+         static inline std::string id() { return OP1; }          \
+      };                                                         \
+
+      define_sfop4(48,(x + ((y + z) / w)),"t+((t+t)/t)")
+      define_sfop4(49,(x + ((y + z) * w)),"t+((t+t)*t)")
+      define_sfop4(50,(x + ((y - z) / w)),"t+((t-t)/t)")
+      define_sfop4(51,(x + ((y - z) * w)),"t+((t-t)*t)")
+      define_sfop4(52,(x + ((y * z) / w)),"t+((t*t)/t)")
+      define_sfop4(53,(x + ((y * z) * w)),"t+((t*t)*t)")
+      define_sfop4(54,(x + ((y / z) + w)),"t+((t/t)+t)")
+      define_sfop4(55,(x + ((y / z) / w)),"t+((t/t)/t)")
+      define_sfop4(56,(x + ((y / z) * w)),"t+((t/t)*t)")
+      define_sfop4(57,(x - ((y + z) / w)),"t-((t+t)/t)")
+      define_sfop4(58,(x - ((y + z) * w)),"t-((t+t)*t)")
+      define_sfop4(59,(x - ((y - z) / w)),"t-((t-t)/t)")
+      define_sfop4(60,(x - ((y - z) * w)),"t-((t-t)*t)")
+      define_sfop4(61,(x - ((y * z) / w)),"t-((t*t)/t)")
+      define_sfop4(62,(x - ((y * z) * w)),"t-((t*t)*t)")
+      define_sfop4(63,(x - ((y / z) / w)),"t-((t/t)/t)")
+      define_sfop4(64,(x - ((y / z) * w)),"t-((t/t)*t)")
+      define_sfop4(65,(((x + y) * z) - w),"((t+t)*t)-t")
+      define_sfop4(66,(((x - y) * z) - w),"((t-t)*t)-t")
+      define_sfop4(67,(((x * y) * z) - w),"((t*t)*t)-t")
+      define_sfop4(68,(((x / y) * z) - w),"((t/t)*t)-t")
+      define_sfop4(69,(((x + y) / z) - w),"((t+t)/t)-t")
+      define_sfop4(70,(((x - y) / z) - w),"((t-t)/t)-t")
+      define_sfop4(71,(((x * y) / z) - w),"((t*t)/t)-t")
+      define_sfop4(72,(((x / y) / z) - w),"((t/t)/t)-t")
+      define_sfop4(73,((x * y) + (z * w)),"(t*t)+(t*t)")
+      define_sfop4(74,((x * y) - (z * w)),"(t*t)-(t*t)")
+      define_sfop4(75,((x * y) + (z / w)),"(t*t)+(t/t)")
+      define_sfop4(76,((x * y) - (z / w)),"(t*t)-(t/t)")
+      define_sfop4(77,((x / y) + (z / w)),"(t/t)+(t/t)")
+      define_sfop4(78,((x / y) - (z / w)),"(t/t)-(t/t)")
+      define_sfop4(79,((x / y) - (z * w)),"(t/t)-(t*t)")
+      define_sfop4(80,(x / (y + (z * w))),"t/(t+(t*t))")
+      define_sfop4(81,(x / (y - (z * w))),"t/(t-(t*t))")
+      define_sfop4(82,(x * (y + (z * w))),"t*(t+(t*t))")
+      define_sfop4(83,(x * (y - (z * w))),"t*(t-(t*t))")
+
+      define_sfop4(84,(axn<T,2>(x,y) + axn<T,2>(z,w)),"")
+      define_sfop4(85,(axn<T,3>(x,y) + axn<T,3>(z,w)),"")
+      define_sfop4(86,(axn<T,4>(x,y) + axn<T,4>(z,w)),"")
+      define_sfop4(87,(axn<T,5>(x,y) + axn<T,5>(z,w)),"")
+      define_sfop4(88,(axn<T,6>(x,y) + axn<T,6>(z,w)),"")
+      define_sfop4(89,(axn<T,7>(x,y) + axn<T,7>(z,w)),"")
+      define_sfop4(90,(axn<T,8>(x,y) + axn<T,8>(z,w)),"")
+      define_sfop4(91,(axn<T,9>(x,y) + axn<T,9>(z,w)),"")
+      define_sfop4(92,((details::is_true(x) && details::is_true(y)) ? z : w),"")
+      define_sfop4(93,((details::is_true(x) || details::is_true(y)) ? z : w),"")
+      define_sfop4(94,((x <  y) ? z : w),"")
+      define_sfop4(95,((x <= y) ? z : w),"")
+      define_sfop4(96,((x >  y) ? z : w),"")
+      define_sfop4(97,((x >= y) ? z : w),"")
+      define_sfop4(98,(details::is_true(numeric::equal(x,y)) ? z : w),"")
+      define_sfop4(99,(x * numeric::sin(y) + z * numeric::cos(w)),"")
+
+      define_sfop4(ext00,((x + y) - (z * w)),"(t+t)-(t*t)")
+      define_sfop4(ext01,((x + y) - (z / w)),"(t+t)-(t/t)")
+      define_sfop4(ext02,((x + y) + (z * w)),"(t+t)+(t*t)")
+      define_sfop4(ext03,((x + y) + (z / w)),"(t+t)+(t/t)")
+      define_sfop4(ext04,((x - y) + (z * w)),"(t-t)+(t*t)")
+      define_sfop4(ext05,((x - y) + (z / w)),"(t-t)+(t/t)")
+      define_sfop4(ext06,((x - y) - (z * w)),"(t-t)-(t*t)")
+      define_sfop4(ext07,((x - y) - (z / w)),"(t-t)-(t/t)")
+      define_sfop4(ext08,((x + y) - (z - w)),"(t+t)-(t-t)")
+      define_sfop4(ext09,((x + y) + (z - w)),"(t+t)+(t-t)")
+      define_sfop4(ext10,((x + y) + (z + w)),"(t+t)+(t+t)")
+      define_sfop4(ext11,((x + y) * (z - w)),"(t+t)*(t-t)")
+      define_sfop4(ext12,((x + y) / (z - w)),"(t+t)/(t-t)")
+      define_sfop4(ext13,((x - y) - (z + w)),"(t-t)-(t+t)")
+      define_sfop4(ext14,((x - y) + (z + w)),"(t-t)+(t+t)")
+      define_sfop4(ext15,((x - y) * (z + w)),"(t-t)*(t+t)")
+      define_sfop4(ext16,((x - y) / (z + w)),"(t-t)/(t+t)")
+      define_sfop4(ext17,((x * y) - (z + w)),"(t*t)-(t+t)")
+      define_sfop4(ext18,((x / y) - (z + w)),"(t/t)-(t+t)")
+      define_sfop4(ext19,((x * y) + (z + w)),"(t*t)+(t+t)")
+      define_sfop4(ext20,((x / y) + (z + w)),"(t/t)+(t+t)")
+      define_sfop4(ext21,((x * y) + (z - w)),"(t*t)+(t-t)")
+      define_sfop4(ext22,((x / y) + (z - w)),"(t/t)+(t-t)")
+      define_sfop4(ext23,((x * y) - (z - w)),"(t*t)-(t-t)")
+      define_sfop4(ext24,((x / y) - (z - w)),"(t/t)-(t-t)")
+      define_sfop4(ext25,((x + y) * (z * w)),"(t+t)*(t*t)")
+      define_sfop4(ext26,((x + y) * (z / w)),"(t+t)*(t/t)")
+      define_sfop4(ext27,((x + y) / (z * w)),"(t+t)/(t*t)")
+      define_sfop4(ext28,((x + y) / (z / w)),"(t+t)/(t/t)")
+      define_sfop4(ext29,((x - y) / (z * w)),"(t-t)/(t*t)")
+      define_sfop4(ext30,((x - y) / (z / w)),"(t-t)/(t/t)")
+      define_sfop4(ext31,((x - y) * (z * w)),"(t-t)*(t*t)")
+      define_sfop4(ext32,((x - y) * (z / w)),"(t-t)*(t/t)")
+      define_sfop4(ext33,((x * y) * (z + w)),"(t*t)*(t+t)")
+      define_sfop4(ext34,((x / y) * (z + w)),"(t/t)*(t+t)")
+      define_sfop4(ext35,((x * y) / (z + w)),"(t*t)/(t+t)")
+      define_sfop4(ext36,((x / y) / (z + w)),"(t/t)/(t+t)")
+      define_sfop4(ext37,((x * y) / (z - w)),"(t*t)/(t-t)")
+      define_sfop4(ext38,((x / y) / (z - w)),"(t/t)/(t-t)")
+      define_sfop4(ext39,((x * y) * (z - w)),"(t*t)*(t-t)")
+      define_sfop4(ext40,((x * y) / (z * w)),"(t*t)/(t*t)")
+      define_sfop4(ext41,((x / y) * (z / w)),"(t/t)*(t/t)")
+      define_sfop4(ext42,((x / y) * (z - w)),"(t/t)*(t-t)")
+      define_sfop4(ext43,((x * y) * (z * w)),"(t*t)*(t*t)")
+      define_sfop4(ext44,(x + (y * (z / w))),"t+(t*(t/t))")
+      define_sfop4(ext45,(x - (y * (z / w))),"t-(t*(t/t))")
+      define_sfop4(ext46,(x + (y / (z * w))),"t+(t/(t*t))")
+      define_sfop4(ext47,(x - (y / (z * w))),"t-(t/(t*t))")
+      define_sfop4(ext48,(((x - y) - z) * w),"((t-t)-t)*t")
+      define_sfop4(ext49,(((x - y) - z) / w),"((t-t)-t)/t")
+      define_sfop4(ext50,(((x - y) + z) * w),"((t-t)+t)*t")
+      define_sfop4(ext51,(((x - y) + z) / w),"((t-t)+t)/t")
+      define_sfop4(ext52,((x + (y - z)) * w),"(t+(t-t))*t")
+      define_sfop4(ext53,((x + (y - z)) / w),"(t+(t-t))/t")
+      define_sfop4(ext54,((x + y) / (z + w)),"(t+t)/(t+t)")
+      define_sfop4(ext55,((x - y) / (z - w)),"(t-t)/(t-t)")
+      define_sfop4(ext56,((x + y) * (z + w)),"(t+t)*(t+t)")
+      define_sfop4(ext57,((x - y) * (z - w)),"(t-t)*(t-t)")
+      define_sfop4(ext58,((x - y) + (z - w)),"(t-t)+(t-t)")
+      define_sfop4(ext59,((x - y) - (z - w)),"(t-t)-(t-t)")
+      define_sfop4(ext60,((x / y) + (z * w)),"(t/t)+(t*t)")
+      define_sfop4(ext61,(((x * y) * z) / w),"((t*t)*t)/t")
+
+      #undef define_sfop3
+      #undef define_sfop4
+
+      template <typename T, typename SpecialFunction>
+      class sf3_node : public trinary_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+
+         sf3_node(const operator_type& opr,
+                  expression_ptr branch0,
+                  expression_ptr branch1,
+                  expression_ptr branch2)
+         : trinary_node<T>(opr, branch0, branch1, branch2)
+         {}
+
+         inline T value() const
+         {
+            const T x = trinary_node<T>::branch_[0].first->value();
+            const T y = trinary_node<T>::branch_[1].first->value();
+            const T z = trinary_node<T>::branch_[2].first->value();
+
+            return SpecialFunction::process(x, y, z);
+         }
+      };
+
+      template <typename T, typename SpecialFunction>
+      class sf4_node : public quaternary_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+
+         sf4_node(const operator_type& opr,
+                  expression_ptr branch0,
+                  expression_ptr branch1,
+                  expression_ptr branch2,
+                  expression_ptr branch3)
+         : quaternary_node<T>(opr, branch0, branch1, branch2, branch3)
+         {}
+
+         inline T value() const
+         {
+            const T x = quaternary_node<T>::branch_[0].first->value();
+            const T y = quaternary_node<T>::branch_[1].first->value();
+            const T z = quaternary_node<T>::branch_[2].first->value();
+            const T w = quaternary_node<T>::branch_[3].first->value();
+
+            return SpecialFunction::process(x, y, z, w);
+         }
+      };
+
+      template <typename T, typename SpecialFunction>
+      class sf3_var_node : public expression_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+
+         sf3_var_node(const T& v0, const T& v1, const T& v2)
+         : v0_(v0),
+           v1_(v1),
+           v2_(v2)
+         {}
+
+         inline T value() const
+         {
+            return SpecialFunction::process(v0_, v1_, v2_);
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_trinary;
+         }
+
+      private:
+
+         sf3_var_node(sf3_var_node<T,SpecialFunction>&);
+         sf3_var_node<T,SpecialFunction>& operator=(sf3_var_node<T,SpecialFunction>&);
+
+         const T& v0_;
+         const T& v1_;
+         const T& v2_;
+      };
+
+      template <typename T, typename SpecialFunction>
+      class sf4_var_node : public expression_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+
+         sf4_var_node(const T& v0, const T& v1, const T& v2, const T& v3)
+         : v0_(v0),
+           v1_(v1),
+           v2_(v2),
+           v3_(v3)
+         {}
+
+         inline T value() const
+         {
+            return SpecialFunction::process(v0_, v1_, v2_, v3_);
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_trinary;
+         }
+
+      private:
+
+         sf4_var_node(sf4_var_node<T,SpecialFunction>&);
+         sf4_var_node<T,SpecialFunction>& operator=(sf4_var_node<T,SpecialFunction>&);
+
+         const T& v0_;
+         const T& v1_;
+         const T& v2_;
+         const T& v3_;
+      };
+
+      template <typename T, typename VarArgFunction>
+      class vararg_node : public expression_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+
+         template <typename Allocator,
+                   template <typename, typename> class Sequence>
+         explicit vararg_node(const Sequence<expression_ptr,Allocator>& arg_list)
+         {
+            arg_list_     .resize(arg_list.size());
+            delete_branch_.resize(arg_list.size());
+
+            for (std::size_t i = 0; i < arg_list.size(); ++i)
+            {
+               if (arg_list[i])
+               {
+                       arg_list_[i] = arg_list[i];
+                  delete_branch_[i] = static_cast<unsigned char>(branch_deletable(arg_list_[i]) ? 1 : 0);
+               }
+               else
+               {
+                  arg_list_.clear();
+                  delete_branch_.clear();
+                  return;
+               }
+            }
+         }
+
+        ~vararg_node()
+         {
+            for (std::size_t i = 0; i < arg_list_.size(); ++i)
+            {
+               if (arg_list_[i] && delete_branch_[i])
+               {
+                  destroy_node(arg_list_[i]);
+               }
+            }
+         }
+
+         inline T value() const
+         {
+            return VarArgFunction::process(arg_list_);
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_vararg;
+         }
+
+      private:
+
+         std::vector<expression_ptr> arg_list_;
+         std::vector<unsigned char> delete_branch_;
+      };
+
+      template <typename T, typename VarArgFunction>
+      class vararg_varnode : public expression_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+
+         template <typename Allocator,
+                   template <typename, typename> class Sequence>
+         explicit vararg_varnode(const Sequence<expression_ptr,Allocator>& arg_list)
+         {
+            arg_list_.resize(arg_list.size());
+
+            for (std::size_t i = 0; i < arg_list.size(); ++i)
+            {
+               if (arg_list[i] && is_variable_node(arg_list[i]))
+               {
+                  variable_node<T>* var_node_ptr = static_cast<variable_node<T>*>(arg_list[i]);
+                  arg_list_[i] = (&var_node_ptr->ref());
+               }
+               else
+               {
+                  arg_list_.clear();
+                  return;
+               }
+            }
+         }
+
+         inline T value() const
+         {
+            if (!arg_list_.empty())
+               return VarArgFunction::process(arg_list_);
+            else
+               return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_vararg;
+         }
+
+      private:
+
+         std::vector<const T*> arg_list_;
+      };
+
+      template <typename T, typename VecFunction>
+      class vectorize_node : public expression_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+
+         explicit vectorize_node(const expression_ptr v)
+         : ivec_ptr_(0),
+           v_(v),
+           v_deletable_(branch_deletable(v_))
+         {
+            if (is_ivector_node(v))
+            {
+               ivec_ptr_ = dynamic_cast<vector_interface<T>*>(v);
+            }
+            else
+               ivec_ptr_ = 0;
+         }
+
+        ~vectorize_node()
+         {
+            if (v_ && v_deletable_)
+            {
+               destroy_node(v_);
+            }
+         }
+
+         inline T value() const
+         {
+            if (ivec_ptr_)
+            {
+               v_->value();
+               return VecFunction::process(ivec_ptr_);
+            }
+            else
+               return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_vecfunc;
+         }
+
+      private:
+
+         vector_interface<T>* ivec_ptr_;
+         expression_ptr              v_;
+         const bool        v_deletable_;
+      };
+
+      template <typename T>
+      class assignment_node : public binary_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+
+         assignment_node(const operator_type& opr,
+                         expression_ptr branch0,
+                         expression_ptr branch1)
+         : binary_node<T>(opr, branch0, branch1),
+           var_node_ptr_(0)
+         {
+            if (is_variable_node(binary_node<T>::branch_[0].first))
+            {
+               var_node_ptr_ = static_cast<variable_node<T>*>(binary_node<T>::branch_[0].first);
+            }
+         }
+
+         inline T value() const
+         {
+            if (var_node_ptr_)
+            {
+               T& result = var_node_ptr_->ref();
+
+               result = binary_node<T>::branch_[1].first->value();
+
+               return result;
+            }
+            else
+               return std::numeric_limits<T>::quiet_NaN();
+         }
+
+      private:
+
+         variable_node<T>* var_node_ptr_;
+      };
+
+      template <typename T>
+      class assignment_vec_elem_node : public binary_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+
+         assignment_vec_elem_node(const operator_type& opr,
+                                  expression_ptr branch0,
+                                  expression_ptr branch1)
+         : binary_node<T>(opr, branch0, branch1),
+           vec_node_ptr_(0)
+         {
+            if (is_vector_elem_node(binary_node<T>::branch_[0].first))
+            {
+               vec_node_ptr_ = static_cast<vector_elem_node<T>*>(binary_node<T>::branch_[0].first);
+            }
+         }
+
+         inline T value() const
+         {
+            if (vec_node_ptr_)
+            {
+               T& result = vec_node_ptr_->ref();
+
+               result = binary_node<T>::branch_[1].first->value();
+
+               return result;
+            }
+            else
+               return std::numeric_limits<T>::quiet_NaN();
+         }
+
+      private:
+
+         vector_elem_node<T>* vec_node_ptr_;
+      };
+
+      template <typename T>
+      class assignment_rebasevec_elem_node : public binary_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+
+         assignment_rebasevec_elem_node(const operator_type& opr,
+                                        expression_ptr branch0,
+                                        expression_ptr branch1)
+         : binary_node<T>(opr, branch0, branch1),
+           rbvec_node_ptr_(0)
+         {
+            if (is_rebasevector_elem_node(binary_node<T>::branch_[0].first))
+            {
+               rbvec_node_ptr_ = static_cast<rebasevector_elem_node<T>*>(binary_node<T>::branch_[0].first);
+            }
+         }
+
+         inline T value() const
+         {
+            if (rbvec_node_ptr_)
+            {
+               T& result = rbvec_node_ptr_->ref();
+
+               result = binary_node<T>::branch_[1].first->value();
+
+               return result;
+            }
+            else
+               return std::numeric_limits<T>::quiet_NaN();
+         }
+
+      private:
+
+         rebasevector_elem_node<T>* rbvec_node_ptr_;
+      };
+
+      template <typename T>
+      class assignment_rebasevec_celem_node : public binary_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+
+         assignment_rebasevec_celem_node(const operator_type& opr,
+                                         expression_ptr branch0,
+                                         expression_ptr branch1)
+         : binary_node<T>(opr, branch0, branch1),
+           rbvec_node_ptr_(0)
+         {
+            if (is_rebasevector_celem_node(binary_node<T>::branch_[0].first))
+            {
+               rbvec_node_ptr_ = static_cast<rebasevector_celem_node<T>*>(binary_node<T>::branch_[0].first);
+            }
+         }
+
+         inline T value() const
+         {
+            if (rbvec_node_ptr_)
+            {
+               T& result = rbvec_node_ptr_->ref();
+
+               result = binary_node<T>::branch_[1].first->value();
+
+               return result;
+            }
+            else
+               return std::numeric_limits<T>::quiet_NaN();
+         }
+
+      private:
+
+         rebasevector_celem_node<T>* rbvec_node_ptr_;
+      };
+
+      template <typename T>
+      class assignment_vec_node : public binary_node     <T>,
+                                  public vector_interface<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+         typedef vector_node<T>*    vector_node_ptr;
+         typedef vec_data_store<T>            vds_t;
+
+         assignment_vec_node(const operator_type& opr,
+                             expression_ptr branch0,
+                             expression_ptr branch1)
+         : binary_node<T>(opr, branch0, branch1),
+           vec_node_ptr_(0)
+         {
+            if (is_vector_node(binary_node<T>::branch_[0].first))
+            {
+               vec_node_ptr_ = static_cast<vector_node<T>*>(binary_node<T>::branch_[0].first);
+               vds()         = vec_node_ptr_->vds();
+            }
+         }
+
+         inline T value() const
+         {
+            if (vec_node_ptr_)
+            {
+               const T v = binary_node<T>::branch_[1].first->value();
+
+               T* vec = vds().data();
+
+               loop_unroll::details lud(size());
+               const T* upper_bound = vec + lud.upper_bound;
+
+               while (vec < upper_bound)
+               {
+                  #define exprtk_loop(N) \
+                  vec[N] = v;            \
+
+                  exprtk_loop( 0) exprtk_loop( 1)
+                  exprtk_loop( 2) exprtk_loop( 3)
+                  #ifndef exprtk_disable_superscalar_unroll
+                  exprtk_loop( 4) exprtk_loop( 5)
+                  exprtk_loop( 6) exprtk_loop( 7)
+                  exprtk_loop( 8) exprtk_loop( 9)
+                  exprtk_loop(10) exprtk_loop(11)
+                  exprtk_loop(12) exprtk_loop(13)
+                  exprtk_loop(14) exprtk_loop(15)
+                  #endif
+
+                  vec += lud.batch_size;
+               }
+
+               exprtk_disable_fallthrough_begin
+               switch (lud.remainder)
+               {
+                  #define case_stmt(N) \
+                  case N : *vec++ = v; \
+
+                  #ifndef exprtk_disable_superscalar_unroll
+                  case_stmt(15) case_stmt(14)
+                  case_stmt(13) case_stmt(12)
+                  case_stmt(11) case_stmt(10)
+                  case_stmt( 9) case_stmt( 8)
+                  case_stmt( 7) case_stmt( 6)
+                  case_stmt( 5) case_stmt( 4)
+                  #endif
+                  case_stmt( 3) case_stmt( 2)
+                  case_stmt( 1)
+               }
+               exprtk_disable_fallthrough_end
+
+               #undef exprtk_loop
+               #undef case_stmt
+
+               return vec_node_ptr_->value();
+            }
+            else
+               return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         vector_node_ptr vec() const
+         {
+            return vec_node_ptr_;
+         }
+
+         vector_node_ptr vec()
+         {
+            return vec_node_ptr_;
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_vecvalass;
+         }
+
+         std::size_t size() const
+         {
+            return vds().size();
+         }
+
+         vds_t& vds()
+         {
+            return vds_;
+         }
+
+         const vds_t& vds() const
+         {
+            return vds_;
+         }
+
+      private:
+
+         vector_node<T>* vec_node_ptr_;
+         vds_t           vds_;
+      };
+
+      template <typename T>
+      class assignment_vecvec_node : public binary_node     <T>,
+                                     public vector_interface<T>
+      {
+      public:
+
+         typedef expression_node<T>*  expression_ptr;
+         typedef vector_node<T>*     vector_node_ptr;
+         typedef vec_data_store<T>             vds_t;
+
+         assignment_vecvec_node(const operator_type& opr,
+                                expression_ptr branch0,
+                                expression_ptr branch1)
+         : binary_node<T>(opr, branch0, branch1),
+           vec0_node_ptr_(0),
+           vec1_node_ptr_(0),
+           initialised_(false),
+           src_is_ivec_(false)
+         {
+            if (is_vector_node(binary_node<T>::branch_[0].first))
+            {
+               vec0_node_ptr_ = static_cast<vector_node<T>*>(binary_node<T>::branch_[0].first);
+               vds()          = vec0_node_ptr_->vds();
+            }
+
+            if (is_vector_node(binary_node<T>::branch_[1].first))
+            {
+               vec1_node_ptr_ = static_cast<vector_node<T>*>(binary_node<T>::branch_[1].first);
+               vds_t::match_sizes(vds(),vec1_node_ptr_->vds());
+            }
+            else if (is_ivector_node(binary_node<T>::branch_[1].first))
+            {
+               vector_interface<T>* vi = reinterpret_cast<vector_interface<T>*>(0);
+
+               if (0 != (vi = dynamic_cast<vector_interface<T>*>(binary_node<T>::branch_[1].first)))
+               {
+                  vec1_node_ptr_ = vi->vec();
+
+                  if (!vi->side_effect())
+                  {
+                     vi->vds()    = vds();
+                     src_is_ivec_ = true;
+                  }
+                  else
+                     vds_t::match_sizes(vds(),vi->vds());
+               }
+            }
+
+            initialised_ = (vec0_node_ptr_ && vec1_node_ptr_);
+         }
+
+         inline T value() const
+         {
+            if (initialised_)
+            {
+               binary_node<T>::branch_[1].first->value();
+
+               if (src_is_ivec_)
+                  return vec0_node_ptr_->value();
+
+               T* vec0 = vec0_node_ptr_->vds().data();
+               T* vec1 = vec1_node_ptr_->vds().data();
+
+               loop_unroll::details lud(size());
+               const T* upper_bound = vec0 + lud.upper_bound;
+
+               while (vec0 < upper_bound)
+               {
+                  #define exprtk_loop(N) \
+                  vec0[N] = vec1[N];     \
+
+                  exprtk_loop( 0) exprtk_loop( 1)
+                  exprtk_loop( 2) exprtk_loop( 3)
+                  #ifndef exprtk_disable_superscalar_unroll
+                  exprtk_loop( 4) exprtk_loop( 5)
+                  exprtk_loop( 6) exprtk_loop( 7)
+                  exprtk_loop( 8) exprtk_loop( 9)
+                  exprtk_loop(10) exprtk_loop(11)
+                  exprtk_loop(12) exprtk_loop(13)
+                  exprtk_loop(14) exprtk_loop(15)
+                  #endif
+
+                  vec0 += lud.batch_size;
+                  vec1 += lud.batch_size;
+               }
+
+               exprtk_disable_fallthrough_begin
+               switch (lud.remainder)
+               {
+                  #define case_stmt(N)        \
+                  case N : *vec0++ = *vec1++; \
+
+                  #ifndef exprtk_disable_superscalar_unroll
+                  case_stmt(15) case_stmt(14)
+                  case_stmt(13) case_stmt(12)
+                  case_stmt(11) case_stmt(10)
+                  case_stmt( 9) case_stmt( 8)
+                  case_stmt( 7) case_stmt( 6)
+                  case_stmt( 5) case_stmt( 4)
+                  #endif
+                  case_stmt( 3) case_stmt( 2)
+                  case_stmt( 1)
+               }
+               exprtk_disable_fallthrough_end
+
+               #undef exprtk_loop
+               #undef case_stmt
+
+               return vec0_node_ptr_->value();
+            }
+            else
+               return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         vector_node_ptr vec() const
+         {
+            return vec0_node_ptr_;
+         }
+
+         vector_node_ptr vec()
+         {
+            return vec0_node_ptr_;
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_vecvecass;
+         }
+
+         std::size_t size() const
+         {
+            return vds().size();
+         }
+
+         vds_t& vds()
+         {
+            return vds_;
+         }
+
+         const vds_t& vds() const
+         {
+            return vds_;
+         }
+
+      private:
+
+         vector_node<T>* vec0_node_ptr_;
+         vector_node<T>* vec1_node_ptr_;
+         bool            initialised_;
+         bool            src_is_ivec_;
+         vds_t           vds_;
+      };
+
+      template <typename T, typename Operation>
+      class assignment_op_node : public binary_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+
+         assignment_op_node(const operator_type& opr,
+                            expression_ptr branch0,
+                            expression_ptr branch1)
+         : binary_node<T>(opr, branch0, branch1),
+           var_node_ptr_(0)
+         {
+            if (is_variable_node(binary_node<T>::branch_[0].first))
+            {
+               var_node_ptr_ = static_cast<variable_node<T>*>(binary_node<T>::branch_[0].first);
+            }
+         }
+
+         inline T value() const
+         {
+            if (var_node_ptr_)
+            {
+               T& v = var_node_ptr_->ref();
+               v = Operation::process(v,binary_node<T>::branch_[1].first->value());
+
+               return v;
+            }
+            else
+               return std::numeric_limits<T>::quiet_NaN();
+         }
+
+      private:
+
+         variable_node<T>* var_node_ptr_;
+      };
+
+      template <typename T, typename Operation>
+      class assignment_vec_elem_op_node : public binary_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+
+         assignment_vec_elem_op_node(const operator_type& opr,
+                                     expression_ptr branch0,
+                                     expression_ptr branch1)
+         : binary_node<T>(opr, branch0, branch1),
+           vec_node_ptr_(0)
+         {
+            if (is_vector_elem_node(binary_node<T>::branch_[0].first))
+            {
+               vec_node_ptr_ = static_cast<vector_elem_node<T>*>(binary_node<T>::branch_[0].first);
+            }
+         }
+
+         inline T value() const
+         {
+            if (vec_node_ptr_)
+            {
+               T& v = vec_node_ptr_->ref();
+                  v = Operation::process(v,binary_node<T>::branch_[1].first->value());
+
+               return v;
+            }
+            else
+               return std::numeric_limits<T>::quiet_NaN();
+         }
+
+      private:
+
+         vector_elem_node<T>* vec_node_ptr_;
+      };
+
+      template <typename T, typename Operation>
+      class assignment_rebasevec_elem_op_node : public binary_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+
+         assignment_rebasevec_elem_op_node(const operator_type& opr,
+                                           expression_ptr branch0,
+                                           expression_ptr branch1)
+         : binary_node<T>(opr, branch0, branch1),
+           rbvec_node_ptr_(0)
+         {
+            if (is_rebasevector_elem_node(binary_node<T>::branch_[0].first))
+            {
+               rbvec_node_ptr_ = static_cast<rebasevector_elem_node<T>*>(binary_node<T>::branch_[0].first);
+            }
+         }
+
+         inline T value() const
+         {
+            if (rbvec_node_ptr_)
+            {
+               T& v = rbvec_node_ptr_->ref();
+                  v = Operation::process(v,binary_node<T>::branch_[1].first->value());
+
+               return v;
+            }
+            else
+               return std::numeric_limits<T>::quiet_NaN();
+         }
+
+      private:
+
+         rebasevector_elem_node<T>* rbvec_node_ptr_;
+      };
+
+      template <typename T, typename Operation>
+      class assignment_rebasevec_celem_op_node : public binary_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+
+         assignment_rebasevec_celem_op_node(const operator_type& opr,
+                                            expression_ptr branch0,
+                                            expression_ptr branch1)
+         : binary_node<T>(opr, branch0, branch1),
+           rbvec_node_ptr_(0)
+         {
+            if (is_rebasevector_celem_node(binary_node<T>::branch_[0].first))
+            {
+               rbvec_node_ptr_ = static_cast<rebasevector_celem_node<T>*>(binary_node<T>::branch_[0].first);
+            }
+         }
+
+         inline T value() const
+         {
+            if (rbvec_node_ptr_)
+            {
+               T& v = rbvec_node_ptr_->ref();
+                  v = Operation::process(v,binary_node<T>::branch_[1].first->value());
+
+               return v;
+            }
+            else
+               return std::numeric_limits<T>::quiet_NaN();
+         }
+
+      private:
+
+         rebasevector_celem_node<T>* rbvec_node_ptr_;
+      };
+
+      template <typename T, typename Operation>
+      class assignment_vec_op_node : public binary_node     <T>,
+                                     public vector_interface<T>
+      {
+      public:
+
+         typedef expression_node<T>*  expression_ptr;
+         typedef vector_node<T>*     vector_node_ptr;
+         typedef vec_data_store<T>             vds_t;
+
+         assignment_vec_op_node(const operator_type& opr,
+                                expression_ptr branch0,
+                                expression_ptr branch1)
+         : binary_node<T>(opr, branch0, branch1),
+           vec_node_ptr_(0)
+         {
+            if (is_vector_node(binary_node<T>::branch_[0].first))
+            {
+               vec_node_ptr_ = static_cast<vector_node<T>*>(binary_node<T>::branch_[0].first);
+               vds()         = vec_node_ptr_->vds();
+            }
+         }
+
+         inline T value() const
+         {
+            if (vec_node_ptr_)
+            {
+               const T v = binary_node<T>::branch_[1].first->value();
+
+               T* vec = vds().data();
+
+               loop_unroll::details lud(size());
+               const T* upper_bound = vec + lud.upper_bound;
+
+               while (vec < upper_bound)
+               {
+                  #define exprtk_loop(N)       \
+                  Operation::assign(vec[N],v); \
+
+                  exprtk_loop( 0) exprtk_loop( 1)
+                  exprtk_loop( 2) exprtk_loop( 3)
+                  #ifndef exprtk_disable_superscalar_unroll
+                  exprtk_loop( 4) exprtk_loop( 5)
+                  exprtk_loop( 6) exprtk_loop( 7)
+                  exprtk_loop( 8) exprtk_loop( 9)
+                  exprtk_loop(10) exprtk_loop(11)
+                  exprtk_loop(12) exprtk_loop(13)
+                  exprtk_loop(14) exprtk_loop(15)
+                  #endif
+
+                  vec += lud.batch_size;
+               }
+
+               exprtk_disable_fallthrough_begin
+               switch (lud.remainder)
+               {
+                  #define case_stmt(N)                  \
+                  case N : Operation::assign(*vec++,v); \
+
+                  #ifndef exprtk_disable_superscalar_unroll
+                  case_stmt(15) case_stmt(14)
+                  case_stmt(13) case_stmt(12)
+                  case_stmt(11) case_stmt(10)
+                  case_stmt( 9) case_stmt( 8)
+                  case_stmt( 7) case_stmt( 6)
+                  case_stmt( 5) case_stmt( 4)
+                  #endif
+                  case_stmt( 3) case_stmt( 2)
+                  case_stmt( 1)
+               }
+               exprtk_disable_fallthrough_end
+
+
+               #undef exprtk_loop
+               #undef case_stmt
+
+               return vec_node_ptr_->value();
+            }
+            else
+               return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         vector_node_ptr vec() const
+         {
+            return vec_node_ptr_;
+         }
+
+         vector_node_ptr vec()
+         {
+            return vec_node_ptr_;
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_vecopvalass;
+         }
+
+         std::size_t size() const
+         {
+            return vds().size();
+         }
+
+         vds_t& vds()
+         {
+            return vds_;
+         }
+
+         const vds_t& vds() const
+         {
+            return vds_;
+         }
+
+         bool side_effect() const
+         {
+            return true;
+         }
+
+      private:
+
+         vector_node<T>* vec_node_ptr_;
+         vds_t           vds_;
+      };
+
+      template <typename T, typename Operation>
+      class assignment_vecvec_op_node : public binary_node     <T>,
+                                        public vector_interface<T>
+      {
+      public:
+
+         typedef expression_node<T>*  expression_ptr;
+         typedef vector_node<T>*     vector_node_ptr;
+         typedef vec_data_store<T>             vds_t;
+
+         assignment_vecvec_op_node(const operator_type& opr,
+                                   expression_ptr branch0,
+                                   expression_ptr branch1)
+         : binary_node<T>(opr, branch0, branch1),
+           vec0_node_ptr_(0),
+           vec1_node_ptr_(0),
+           initialised_(false)
+         {
+            if (is_vector_node(binary_node<T>::branch_[0].first))
+            {
+               vec0_node_ptr_ = static_cast<vector_node<T>*>(binary_node<T>::branch_[0].first);
+               vds()          = vec0_node_ptr_->vds();
+            }
+
+            if (is_vector_node(binary_node<T>::branch_[1].first))
+            {
+               vec1_node_ptr_ = static_cast<vector_node<T>*>(binary_node<T>::branch_[1].first);
+               vec1_node_ptr_->vds() = vds();
+            }
+            else if (is_ivector_node(binary_node<T>::branch_[1].first))
+            {
+               vector_interface<T>* vi = reinterpret_cast<vector_interface<T>*>(0);
+
+               if (0 != (vi = dynamic_cast<vector_interface<T>*>(binary_node<T>::branch_[1].first)))
+               {
+                  vec1_node_ptr_ = vi->vec();
+                  vec1_node_ptr_->vds() = vds();
+               }
+               else
+                  vds_t::match_sizes(vds(),vec1_node_ptr_->vds());
+            }
+
+            initialised_ = (vec0_node_ptr_ && vec1_node_ptr_);
+         }
+
+         inline T value() const
+         {
+            if (initialised_)
+            {
+               binary_node<T>::branch_[0].first->value();
+               binary_node<T>::branch_[1].first->value();
+
+                     T* vec0 = vec0_node_ptr_->vds().data();
+               const T* vec1 = vec1_node_ptr_->vds().data();
+
+               loop_unroll::details lud(size());
+               const T* upper_bound = vec0 + lud.upper_bound;
+
+               while (vec0 < upper_bound)
+               {
+                  #define exprtk_loop(N)                          \
+                  vec0[N] = Operation::process(vec0[N], vec1[N]); \
+
+                  exprtk_loop( 0) exprtk_loop( 1)
+                  exprtk_loop( 2) exprtk_loop( 3)
+                  #ifndef exprtk_disable_superscalar_unroll
+                  exprtk_loop( 4) exprtk_loop( 5)
+                  exprtk_loop( 6) exprtk_loop( 7)
+                  exprtk_loop( 8) exprtk_loop( 9)
+                  exprtk_loop(10) exprtk_loop(11)
+                  exprtk_loop(12) exprtk_loop(13)
+                  exprtk_loop(14) exprtk_loop(15)
+                  #endif
+
+                  vec0 += lud.batch_size;
+                  vec1 += lud.batch_size;
+               }
+
+               int i = 0;
+
+               exprtk_disable_fallthrough_begin
+               switch (lud.remainder)
+               {
+                  #define case_stmt(N)                                              \
+                  case N : { vec0[i] = Operation::process(vec0[i], vec1[i]); ++i; } \
+
+                  #ifndef exprtk_disable_superscalar_unroll
+                  case_stmt(15) case_stmt(14)
+                  case_stmt(13) case_stmt(12)
+                  case_stmt(11) case_stmt(10)
+                  case_stmt( 9) case_stmt( 8)
+                  case_stmt( 7) case_stmt( 6)
+                  case_stmt( 5) case_stmt( 4)
+                  #endif
+                  case_stmt( 3) case_stmt( 2)
+                  case_stmt( 1)
+               }
+               exprtk_disable_fallthrough_end
+
+               #undef exprtk_loop
+               #undef case_stmt
+
+               return vec0_node_ptr_->value();
+            }
+            else
+               return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         vector_node_ptr vec() const
+         {
+            return vec0_node_ptr_;
+         }
+
+         vector_node_ptr vec()
+         {
+            return vec0_node_ptr_;
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_vecopvecass;
+         }
+
+         std::size_t size() const
+         {
+            return vds().size();
+         }
+
+         vds_t& vds()
+         {
+            return vds_;
+         }
+
+         const vds_t& vds() const
+         {
+            return vds_;
+         }
+
+         bool side_effect() const
+         {
+            return true;
+         }
+
+      private:
+
+         vector_node<T>* vec0_node_ptr_;
+         vector_node<T>* vec1_node_ptr_;
+         bool            initialised_;
+         vds_t           vds_;
+      };
+
+      template <typename T, typename Operation>
+      class vec_binop_vecvec_node : public binary_node     <T>,
+                                    public vector_interface<T>
+      {
+      public:
+
+         typedef expression_node<T>*    expression_ptr;
+         typedef vector_node<T>*       vector_node_ptr;
+         typedef vector_holder<T>*   vector_holder_ptr;
+         typedef vec_data_store<T>               vds_t;
+
+         vec_binop_vecvec_node(const operator_type& opr,
+                               expression_ptr branch0,
+                               expression_ptr branch1)
+         : binary_node<T>(opr, branch0, branch1),
+           vec0_node_ptr_(0),
+           vec1_node_ptr_(0),
+           temp_         (0),
+           temp_vec_node_(0),
+           initialised_(false)
+         {
+            bool v0_is_ivec = false;
+            bool v1_is_ivec = false;
+
+            if (is_vector_node(binary_node<T>::branch_[0].first))
+            {
+               vec0_node_ptr_ = static_cast<vector_node_ptr>(binary_node<T>::branch_[0].first);
+            }
+            else if (is_ivector_node(binary_node<T>::branch_[0].first))
+            {
+               vector_interface<T>* vi = reinterpret_cast<vector_interface<T>*>(0);
+
+               if (0 != (vi = dynamic_cast<vector_interface<T>*>(binary_node<T>::branch_[0].first)))
+               {
+                  vec0_node_ptr_ = vi->vec();
+                  v0_is_ivec     = true;
+               }
+            }
+
+            if (is_vector_node(binary_node<T>::branch_[1].first))
+            {
+               vec1_node_ptr_ = static_cast<vector_node_ptr>(binary_node<T>::branch_[1].first);
+            }
+            else if (is_ivector_node(binary_node<T>::branch_[1].first))
+            {
+               vector_interface<T>* vi = reinterpret_cast<vector_interface<T>*>(0);
+
+               if (0 != (vi = dynamic_cast<vector_interface<T>*>(binary_node<T>::branch_[1].first)))
+               {
+                  vec1_node_ptr_ = vi->vec();
+                  v1_is_ivec     = true;
+               }
+            }
+
+            if (vec0_node_ptr_ && vec1_node_ptr_)
+            {
+               vector_holder<T>& vec0 = vec0_node_ptr_->vec_holder();
+               vector_holder<T>& vec1 = vec1_node_ptr_->vec_holder();
+
+               if (v0_is_ivec && (vec0.size() <= vec1.size()))
+                  vds_ = vds_t(vec0_node_ptr_->vds());
+               else if (v1_is_ivec && (vec1.size() <= vec0.size()))
+                  vds_ = vds_t(vec1_node_ptr_->vds());
+               else
+                  vds_ = vds_t(std::min(vec0.size(),vec1.size()));
+
+               temp_          = new vector_holder<T>(vds().data(),vds().size());
+               temp_vec_node_ = new vector_node<T>  (vds(),temp_);
+
+               initialised_ = true;
+            }
+         }
+
+        ~vec_binop_vecvec_node()
+         {
+            delete temp_;
+            delete temp_vec_node_;
+         }
+
+         inline T value() const
+         {
+            if (initialised_)
+            {
+               binary_node<T>::branch_[0].first->value();
+               binary_node<T>::branch_[1].first->value();
+
+               const T* vec0 = vec0_node_ptr_->vds().data();
+               const T* vec1 = vec1_node_ptr_->vds().data();
+                     T* vec2 = vds().data();
+
+               loop_unroll::details lud(size());
+               const T* upper_bound = vec2 + lud.upper_bound;
+
+               while (vec2 < upper_bound)
+               {
+                  #define exprtk_loop(N)                          \
+                  vec2[N] = Operation::process(vec0[N], vec1[N]); \
+
+                  exprtk_loop( 0) exprtk_loop( 1)
+                  exprtk_loop( 2) exprtk_loop( 3)
+                  #ifndef exprtk_disable_superscalar_unroll
+                  exprtk_loop( 4) exprtk_loop( 5)
+                  exprtk_loop( 6) exprtk_loop( 7)
+                  exprtk_loop( 8) exprtk_loop( 9)
+                  exprtk_loop(10) exprtk_loop(11)
+                  exprtk_loop(12) exprtk_loop(13)
+                  exprtk_loop(14) exprtk_loop(15)
+                  #endif
+
+                  vec0 += lud.batch_size;
+                  vec1 += lud.batch_size;
+                  vec2 += lud.batch_size;
+               }
+
+               int i = 0;
+
+               exprtk_disable_fallthrough_begin
+               switch (lud.remainder)
+               {
+                  #define case_stmt(N)                                              \
+                  case N : { vec2[i] = Operation::process(vec0[i], vec1[i]); ++i; } \
+
+                  #ifndef exprtk_disable_superscalar_unroll
+                  case_stmt(15) case_stmt(14)
+                  case_stmt(13) case_stmt(12)
+                  case_stmt(11) case_stmt(10)
+                  case_stmt( 9) case_stmt( 8)
+                  case_stmt( 7) case_stmt( 6)
+                  case_stmt( 5) case_stmt( 4)
+                  #endif
+                  case_stmt( 3) case_stmt( 2)
+                  case_stmt( 1)
+               }
+               exprtk_disable_fallthrough_end
+
+               #undef exprtk_loop
+               #undef case_stmt
+
+               return (vds().data())[0];
+            }
+            else
+               return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         vector_node_ptr vec() const
+         {
+            return temp_vec_node_;
+         }
+
+         vector_node_ptr vec()
+         {
+            return temp_vec_node_;
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_vecvecarith;
+         }
+
+         std::size_t size() const
+         {
+            return vds_.size();
+         }
+
+         vds_t& vds()
+         {
+            return vds_;
+         }
+
+         const vds_t& vds() const
+         {
+            return vds_;
+         }
+
+      private:
+
+         vector_node_ptr   vec0_node_ptr_;
+         vector_node_ptr   vec1_node_ptr_;
+         vector_holder_ptr temp_;
+         vector_node_ptr   temp_vec_node_;
+         bool              initialised_;
+         vds_t             vds_;
+      };
+
+      template <typename T, typename Operation>
+      class vec_binop_vecval_node : public binary_node     <T>,
+                                    public vector_interface<T>
+      {
+      public:
+
+         typedef expression_node<T>*    expression_ptr;
+         typedef vector_node<T>*       vector_node_ptr;
+         typedef vector_holder<T>*   vector_holder_ptr;
+         typedef vec_data_store<T>               vds_t;
+
+         vec_binop_vecval_node(const operator_type& opr,
+                               expression_ptr branch0,
+                               expression_ptr branch1)
+         : binary_node<T>(opr, branch0, branch1),
+           vec0_node_ptr_(0),
+           temp_         (0),
+           temp_vec_node_(0)
+         {
+            bool v0_is_ivec = false;
+
+            if (is_vector_node(binary_node<T>::branch_[0].first))
+            {
+               vec0_node_ptr_ = static_cast<vector_node_ptr>(binary_node<T>::branch_[0].first);
+            }
+            else if (is_ivector_node(binary_node<T>::branch_[0].first))
+            {
+               vector_interface<T>* vi = reinterpret_cast<vector_interface<T>*>(0);
+
+               if (0 != (vi = dynamic_cast<vector_interface<T>*>(binary_node<T>::branch_[0].first)))
+               {
+                  vec0_node_ptr_ = vi->vec();
+                  v0_is_ivec     = true;
+               }
+            }
+
+            if (vec0_node_ptr_)
+            {
+               if (v0_is_ivec)
+                  vds() = vec0_node_ptr_->vds();
+               else
+                  vds() = vds_t(vec0_node_ptr_->size());
+
+               temp_          = new vector_holder<T>(vds());
+               temp_vec_node_ = new vector_node<T>  (vds(),temp_);
+            }
+         }
+
+        ~vec_binop_vecval_node()
+         {
+            delete temp_;
+            delete temp_vec_node_;
+         }
+
+         inline T value() const
+         {
+            if (vec0_node_ptr_)
+            {
+                           binary_node<T>::branch_[0].first->value();
+               const T v = binary_node<T>::branch_[1].first->value();
+
+               const T* vec0 = vec0_node_ptr_->vds().data();
+                     T* vec1 = vds().data();
+
+               loop_unroll::details lud(size());
+               const T* upper_bound = vec0 + lud.upper_bound;
+
+               while (vec0 < upper_bound)
+               {
+                  #define exprtk_loop(N)                    \
+                  vec1[N] = Operation::process(vec0[N], v); \
+
+                  exprtk_loop( 0) exprtk_loop( 1)
+                  exprtk_loop( 2) exprtk_loop( 3)
+                  #ifndef exprtk_disable_superscalar_unroll
+                  exprtk_loop( 4) exprtk_loop( 5)
+                  exprtk_loop( 6) exprtk_loop( 7)
+                  exprtk_loop( 8) exprtk_loop( 9)
+                  exprtk_loop(10) exprtk_loop(11)
+                  exprtk_loop(12) exprtk_loop(13)
+                  exprtk_loop(14) exprtk_loop(15)
+                  #endif
+
+                  vec0 += lud.batch_size;
+                  vec1 += lud.batch_size;
+               }
+
+               int i = 0;
+
+               exprtk_disable_fallthrough_begin
+               switch (lud.remainder)
+               {
+                  #define case_stmt(N)                                        \
+                  case N : { vec1[i] = Operation::process(vec0[i], v); ++i; } \
+
+                  #ifndef exprtk_disable_superscalar_unroll
+                  case_stmt(15) case_stmt(14)
+                  case_stmt(13) case_stmt(12)
+                  case_stmt(11) case_stmt(10)
+                  case_stmt( 9) case_stmt( 8)
+                  case_stmt( 7) case_stmt( 6)
+                  case_stmt( 5) case_stmt( 4)
+                  #endif
+                  case_stmt( 3) case_stmt( 2)
+                  case_stmt( 1)
+               }
+               exprtk_disable_fallthrough_end
+
+               #undef exprtk_loop
+               #undef case_stmt
+
+               return (vds().data())[0];
+            }
+            else
+               return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         vector_node_ptr vec() const
+         {
+            return temp_vec_node_;
+         }
+
+         vector_node_ptr vec()
+         {
+            return temp_vec_node_;
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_vecvalarith;
+         }
+
+         std::size_t size() const
+         {
+            return vds().size();
+         }
+
+         vds_t& vds()
+         {
+            return vds_;
+         }
+
+         const vds_t& vds() const
+         {
+            return vds_;
+         }
+
+      private:
+
+         vector_node_ptr   vec0_node_ptr_;
+         vector_holder_ptr temp_;
+         vector_node_ptr   temp_vec_node_;
+         vds_t             vds_;
+      };
+
+      template <typename T, typename Operation>
+      class vec_binop_valvec_node : public binary_node     <T>,
+                                    public vector_interface<T>
+      {
+      public:
+
+         typedef expression_node<T>*    expression_ptr;
+         typedef vector_node<T>*       vector_node_ptr;
+         typedef vector_holder<T>*   vector_holder_ptr;
+         typedef vec_data_store<T>               vds_t;
+
+         vec_binop_valvec_node(const operator_type& opr,
+                               expression_ptr branch0,
+                               expression_ptr branch1)
+         : binary_node<T>(opr, branch0, branch1),
+           vec1_node_ptr_(0),
+           temp_         (0),
+           temp_vec_node_(0)
+         {
+            bool v1_is_ivec = false;
+
+            if (is_vector_node(binary_node<T>::branch_[1].first))
+            {
+               vec1_node_ptr_ = static_cast<vector_node_ptr>(binary_node<T>::branch_[1].first);
+            }
+            else if (is_ivector_node(binary_node<T>::branch_[1].first))
+            {
+               vector_interface<T>* vi = reinterpret_cast<vector_interface<T>*>(0);
+
+               if (0 != (vi = dynamic_cast<vector_interface<T>*>(binary_node<T>::branch_[1].first)))
+               {
+                  vec1_node_ptr_ = vi->vec();
+                  v1_is_ivec     = true;
+               }
+            }
+
+            if (vec1_node_ptr_)
+            {
+               if (v1_is_ivec)
+                  vds() = vec1_node_ptr_->vds();
+               else
+                  vds() = vds_t(vec1_node_ptr_->size());
+
+               temp_          = new vector_holder<T>(vds());
+               temp_vec_node_ = new vector_node<T>  (vds(),temp_);
+            }
+         }
+
+        ~vec_binop_valvec_node()
+         {
+            delete temp_;
+            delete temp_vec_node_;
+         }
+
+         inline T value() const
+         {
+            if (vec1_node_ptr_)
+            {
+               const T v = binary_node<T>::branch_[0].first->value();
+                           binary_node<T>::branch_[1].first->value();
+
+                     T* vec0 = vds().data();
+               const T* vec1 = vec1_node_ptr_->vds().data();
+
+               loop_unroll::details lud(size());
+               const T* upper_bound = vec0 + lud.upper_bound;
+
+               while (vec0 < upper_bound)
+               {
+                  #define exprtk_loop(N)                    \
+                  vec0[N] = Operation::process(v, vec1[N]); \
+
+                  exprtk_loop( 0) exprtk_loop( 1)
+                  exprtk_loop( 2) exprtk_loop( 3)
+                  #ifndef exprtk_disable_superscalar_unroll
+                  exprtk_loop( 4) exprtk_loop( 5)
+                  exprtk_loop( 6) exprtk_loop( 7)
+                  exprtk_loop( 8) exprtk_loop( 9)
+                  exprtk_loop(10) exprtk_loop(11)
+                  exprtk_loop(12) exprtk_loop(13)
+                  exprtk_loop(14) exprtk_loop(15)
+                  #endif
+
+                  vec0 += lud.batch_size;
+                  vec1 += lud.batch_size;
+               }
+
+               int i = 0;
+
+               exprtk_disable_fallthrough_begin
+               switch (lud.remainder)
+               {
+                  #define case_stmt(N)                                        \
+                  case N : { vec0[i] = Operation::process(v, vec1[i]); ++i; } \
+
+                  #ifndef exprtk_disable_superscalar_unroll
+                  case_stmt(15) case_stmt(14)
+                  case_stmt(13) case_stmt(12)
+                  case_stmt(11) case_stmt(10)
+                  case_stmt( 9) case_stmt( 8)
+                  case_stmt( 7) case_stmt( 6)
+                  case_stmt( 5) case_stmt( 4)
+                  #endif
+                  case_stmt( 3) case_stmt( 2)
+                  case_stmt( 1)
+               }
+               exprtk_disable_fallthrough_end
+
+               #undef exprtk_loop
+               #undef case_stmt
+
+               return (vds().data())[0];
+            }
+            else
+               return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         vector_node_ptr vec() const
+         {
+            return temp_vec_node_;
+         }
+
+         vector_node_ptr vec()
+         {
+            return temp_vec_node_;
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_vecvalarith;
+         }
+
+         std::size_t size() const
+         {
+            return vds().size();
+         }
+
+         vds_t& vds()
+         {
+            return vds_;
+         }
+
+         const vds_t& vds() const
+         {
+            return vds_;
+         }
+
+      private:
+
+         vector_node_ptr   vec1_node_ptr_;
+         vector_holder_ptr temp_;
+         vector_node_ptr   temp_vec_node_;
+         vds_t             vds_;
+      };
+
+      template <typename T, typename Operation>
+      class unary_vector_node : public unary_node      <T>,
+                                public vector_interface<T>
+      {
+      public:
+
+         typedef expression_node<T>*    expression_ptr;
+         typedef vector_node<T>*       vector_node_ptr;
+         typedef vector_holder<T>*   vector_holder_ptr;
+         typedef vec_data_store<T>               vds_t;
+
+         unary_vector_node(const operator_type& opr, expression_ptr branch0)
+         : unary_node<T>(opr, branch0),
+           vec0_node_ptr_(0),
+           temp_         (0),
+           temp_vec_node_(0)
+         {
+            bool vec0_is_ivec = false;
+
+            if (is_vector_node(unary_node<T>::branch_))
+            {
+               vec0_node_ptr_ = static_cast<vector_node_ptr>(unary_node<T>::branch_);
+            }
+            else if (is_ivector_node(unary_node<T>::branch_))
+            {
+               vector_interface<T>* vi = reinterpret_cast<vector_interface<T>*>(0);
+
+               if (0 != (vi = dynamic_cast<vector_interface<T>*>(unary_node<T>::branch_)))
+               {
+                  vec0_node_ptr_ = vi->vec();
+                  vec0_is_ivec   = true;
+               }
+            }
+
+            if (vec0_node_ptr_)
+            {
+               if (vec0_is_ivec)
+                  vds_ = vec0_node_ptr_->vds();
+               else
+                  vds_ = vds_t(vec0_node_ptr_->size());
+
+               temp_          = new vector_holder<T>(vds());
+               temp_vec_node_ = new vector_node<T>  (vds(),temp_);
+            }
+         }
+
+        ~unary_vector_node()
+         {
+            delete temp_;
+            delete temp_vec_node_;
+         }
+
+         inline T value() const
+         {
+            unary_node<T>::branch_->value();
+
+            if (vec0_node_ptr_)
+            {
+               const T* vec0 = vec0_node_ptr_->vds().data();
+                     T* vec1 = vds().data();
+
+               loop_unroll::details lud(size());
+               const T* upper_bound = vec0 + lud.upper_bound;
+
+               while (vec0 < upper_bound)
+               {
+                  #define exprtk_loop(N)                 \
+                  vec1[N] = Operation::process(vec0[N]); \
+
+                  exprtk_loop( 0) exprtk_loop( 1)
+                  exprtk_loop( 2) exprtk_loop( 3)
+                  #ifndef exprtk_disable_superscalar_unroll
+                  exprtk_loop( 4) exprtk_loop( 5)
+                  exprtk_loop( 6) exprtk_loop( 7)
+                  exprtk_loop( 8) exprtk_loop( 9)
+                  exprtk_loop(10) exprtk_loop(11)
+                  exprtk_loop(12) exprtk_loop(13)
+                  exprtk_loop(14) exprtk_loop(15)
+                  #endif
+
+                  vec0 += lud.batch_size;
+                  vec1 += lud.batch_size;
+               }
+
+               int i = 0;
+
+               exprtk_disable_fallthrough_begin
+               switch (lud.remainder)
+               {
+                  #define case_stmt(N)                                     \
+                  case N : { vec1[i] = Operation::process(vec0[i]); ++i; } \
+
+                  #ifndef exprtk_disable_superscalar_unroll
+                  case_stmt(15) case_stmt(14)
+                  case_stmt(13) case_stmt(12)
+                  case_stmt(11) case_stmt(10)
+                  case_stmt( 9) case_stmt( 8)
+                  case_stmt( 7) case_stmt( 6)
+                  case_stmt( 5) case_stmt( 4)
+                  #endif
+                  case_stmt( 3) case_stmt( 2)
+                  case_stmt( 1)
+               }
+               exprtk_disable_fallthrough_end
+
+               #undef exprtk_loop
+               #undef case_stmt
+
+               return (vds().data())[0];
+            }
+            else
+               return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         vector_node_ptr vec() const
+         {
+            return temp_vec_node_;
+         }
+
+         vector_node_ptr vec()
+         {
+            return temp_vec_node_;
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_vecunaryop;
+         }
+
+         std::size_t size() const
+         {
+            return vds().size();
+         }
+
+         vds_t& vds()
+         {
+            return vds_;
+         }
+
+         const vds_t& vds() const
+         {
+            return vds_;
+         }
+
+      private:
+
+         vector_node_ptr   vec0_node_ptr_;
+         vector_holder_ptr temp_;
+         vector_node_ptr   temp_vec_node_;
+         vds_t             vds_;
+      };
+
+      template <typename T>
+      class scand_node : public binary_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+
+         scand_node(const operator_type& opr,
+                    expression_ptr branch0,
+                    expression_ptr branch1)
+         : binary_node<T>(opr, branch0, branch1)
+         {}
+
+         inline T value() const
+         {
+            return (
+                     std::not_equal_to<T>()
+                        (T(0),binary_node<T>::branch_[0].first->value()) &&
+                     std::not_equal_to<T>()
+                        (T(0),binary_node<T>::branch_[1].first->value())
+                   ) ? T(1) : T(0);
+         }
+      };
+
+      template <typename T>
+      class scor_node : public binary_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+
+         scor_node(const operator_type& opr,
+                   expression_ptr branch0,
+                   expression_ptr branch1)
+         : binary_node<T>(opr, branch0, branch1)
+         {}
+
+         inline T value() const
+         {
+            return (
+                     std::not_equal_to<T>()
+                        (T(0),binary_node<T>::branch_[0].first->value()) ||
+                     std::not_equal_to<T>()
+                        (T(0),binary_node<T>::branch_[1].first->value())
+                   ) ? T(1) : T(0);
+         }
+      };
+
+      template <typename T, typename IFunction, std::size_t N>
+      class function_N_node : public expression_node<T>
+      {
+      public:
+
+         // Function of N paramters.
+         typedef expression_node<T>* expression_ptr;
+         typedef std::pair<expression_ptr,bool> branch_t;
+         typedef IFunction ifunction;
+
+         explicit function_N_node(ifunction* func)
+         : function_((N == func->param_count) ? func : reinterpret_cast<ifunction*>(0)),
+           parameter_count_(func->param_count)
+         {}
+
+        ~function_N_node()
+         {
+            cleanup_branches::execute<T,N>(branch_);
+         }
+
+         template <std::size_t NumBranches>
+         bool init_branches(expression_ptr (&b)[NumBranches])
+         {
+            // Needed for incompetent and broken msvc compiler versions
+            #ifdef _MSC_VER
+             #pragma warning(push)
+             #pragma warning(disable: 4127)
+            #endif
+            if (N != NumBranches)
+               return false;
+            else
+            {
+               for (std::size_t i = 0; i < NumBranches; ++i)
+               {
+                  if (b[i])
+                     branch_[i] = std::make_pair(b[i],branch_deletable(b[i]));
+                  else
+                     return false;
+               }
+               return true;
+            }
+            #ifdef _MSC_VER
+             #pragma warning(pop)
+            #endif
+         }
+
+         inline bool operator <(const function_N_node<T,IFunction,N>& fn) const
+         {
+            return this < (&fn);
+         }
+
+         inline T value() const
+         {
+            // Needed for incompetent and broken msvc compiler versions
+            #ifdef _MSC_VER
+             #pragma warning(push)
+             #pragma warning(disable: 4127)
+            #endif
+            if ((0 == function_) || (0 == N))
+               return std::numeric_limits<T>::quiet_NaN();
+            else
+            {
+               T v[N];
+               evaluate_branches<T,N>::execute(v,branch_);
+               return invoke<T,N>::execute(*function_,v);
+            }
+            #ifdef _MSC_VER
+             #pragma warning(pop)
+            #endif
+         }
+
+         template <typename T_, std::size_t BranchCount>
+         struct evaluate_branches
+         {
+            static inline void execute(T_ (&v)[BranchCount], const branch_t (&b)[BranchCount])
+            {
+               for (std::size_t i = 0; i < BranchCount; ++i)
+               {
+                  v[i] = b[i].first->value();
+               }
+            }
+         };
+
+         template <typename T_>
+         struct evaluate_branches <T_,5>
+         {
+            static inline void execute(T_ (&v)[5], const branch_t (&b)[5])
+            {
+               v[0] = b[0].first->value();
+               v[1] = b[1].first->value();
+               v[2] = b[2].first->value();
+               v[3] = b[3].first->value();
+               v[4] = b[4].first->value();
+            }
+         };
+
+         template <typename T_>
+         struct evaluate_branches <T_,4>
+         {
+            static inline void execute(T_ (&v)[4], const branch_t (&b)[4])
+            {
+               v[0] = b[0].first->value();
+               v[1] = b[1].first->value();
+               v[2] = b[2].first->value();
+               v[3] = b[3].first->value();
+            }
+         };
+
+         template <typename T_>
+         struct evaluate_branches <T_,3>
+         {
+            static inline void execute(T_ (&v)[3], const branch_t (&b)[3])
+            {
+               v[0] = b[0].first->value();
+               v[1] = b[1].first->value();
+               v[2] = b[2].first->value();
+            }
+         };
+
+         template <typename T_>
+         struct evaluate_branches <T_,2>
+         {
+            static inline void execute(T_ (&v)[2], const branch_t (&b)[2])
+            {
+               v[0] = b[0].first->value();
+               v[1] = b[1].first->value();
+            }
+         };
+
+         template <typename T_>
+         struct evaluate_branches <T_,1>
+         {
+            static inline void execute(T_ (&v)[1], const branch_t (&b)[1])
+            {
+               v[0] = b[0].first->value();
+            }
+         };
+
+         template <typename T_, std::size_t ParamCount>
+         struct invoke { static inline T execute(ifunction&, branch_t (&)[ParamCount]) { return std::numeric_limits<T_>::quiet_NaN(); } };
+
+         template <typename T_>
+         struct invoke<T_,20>
+         {
+            static inline T_ execute(ifunction& f, T_ (&v)[20])
+            { return f(v[0],v[1],v[2],v[3],v[4],v[5],v[6],v[7],v[8],v[9],v[10],v[11],v[12],v[13],v[14],v[15],v[16],v[17],v[18],v[19]); }
+         };
+
+         template <typename T_>
+         struct invoke<T_,19>
+         {
+            static inline T_ execute(ifunction& f, T_ (&v)[19])
+            { return f(v[0],v[1],v[2],v[3],v[4],v[5],v[6],v[7],v[8],v[9],v[10],v[11],v[12],v[13],v[14],v[15],v[16],v[17],v[18]); }
+         };
+
+         template <typename T_>
+         struct invoke<T_,18>
+         {
+            static inline T_ execute(ifunction& f, T_ (&v)[18])
+            { return f(v[0],v[1],v[2],v[3],v[4],v[5],v[6],v[7],v[8],v[9],v[10],v[11],v[12],v[13],v[14],v[15],v[16],v[17]); }
+         };
+
+         template <typename T_>
+         struct invoke<T_,17>
+         {
+            static inline T_ execute(ifunction& f, T_ (&v)[17])
+            { return f(v[0],v[1],v[2],v[3],v[4],v[5],v[6],v[7],v[8],v[9],v[10],v[11],v[12],v[13],v[14],v[15],v[16]); }
+         };
+
+         template <typename T_>
+         struct invoke<T_,16>
+         {
+            static inline T_ execute(ifunction& f, T_ (&v)[16])
+            { return f(v[0],v[1],v[2],v[3],v[4],v[5],v[6],v[7],v[8],v[9],v[10],v[11],v[12],v[13],v[14],v[15]); }
+         };
+
+         template <typename T_>
+         struct invoke<T_,15>
+         {
+            static inline T_ execute(ifunction& f, T_ (&v)[15])
+            { return f(v[0],v[1],v[2],v[3],v[4],v[5],v[6],v[7],v[8],v[9],v[10],v[11],v[12],v[13],v[14]); }
+         };
+
+         template <typename T_>
+         struct invoke<T_,14>
+         {
+            static inline T_ execute(ifunction& f, T_ (&v)[14])
+            { return f(v[0],v[1],v[2],v[3],v[4],v[5],v[6],v[7],v[8],v[9],v[10],v[11],v[12],v[13]); }
+         };
+
+         template <typename T_>
+         struct invoke<T_,13>
+         {
+            static inline T_ execute(ifunction& f, T_ (&v)[13])
+            { return f(v[0],v[1],v[2],v[3],v[4],v[5],v[6],v[7],v[8],v[9],v[10],v[11],v[12]); }
+         };
+
+         template <typename T_>
+         struct invoke<T_,12>
+         {
+            static inline T_ execute(ifunction& f, T_ (&v)[12])
+            { return f(v[0],v[1],v[2],v[3],v[4],v[5],v[6],v[7],v[8],v[9],v[10],v[11]); }
+         };
+
+         template <typename T_>
+         struct invoke<T_,11>
+         {
+            static inline T_ execute(ifunction& f, T_ (&v)[11])
+            { return f(v[0],v[1],v[2],v[3],v[4],v[5],v[6],v[7],v[8],v[9],v[10]); }
+         };
+
+         template <typename T_>
+         struct invoke<T_,10>
+         {
+            static inline T_ execute(ifunction& f, T_ (&v)[10])
+            { return f(v[0],v[1],v[2],v[3],v[4],v[5],v[6],v[7],v[8],v[9]); }
+         };
+
+         template <typename T_>
+         struct invoke<T_,9>
+         {
+            static inline T_ execute(ifunction& f, T_ (&v)[9])
+            { return f(v[0],v[1],v[2],v[3],v[4],v[5],v[6],v[7],v[8]); }
+         };
+
+         template <typename T_>
+         struct invoke<T_,8>
+         {
+            static inline T_ execute(ifunction& f, T_ (&v)[8])
+            { return f(v[0],v[1],v[2],v[3],v[4],v[5],v[6],v[7]); }
+         };
+
+         template <typename T_>
+         struct invoke<T_,7>
+         {
+            static inline T_ execute(ifunction& f, T_ (&v)[7])
+            { return f(v[0],v[1],v[2],v[3],v[4],v[5],v[6]); }
+         };
+
+         template <typename T_>
+         struct invoke<T_,6>
+         {
+            static inline T_ execute(ifunction& f, T_ (&v)[6])
+            { return f(v[0],v[1],v[2],v[3],v[4],v[5]); }
+         };
+
+         template <typename T_>
+         struct invoke<T_,5>
+         {
+            static inline T_ execute(ifunction& f, T_ (&v)[5])
+            { return f(v[0],v[1],v[2],v[3],v[4]); }
+         };
+
+         template <typename T_>
+         struct invoke<T_,4>
+         {
+            static inline T_ execute(ifunction& f, T_ (&v)[4])
+            { return f(v[0],v[1],v[2],v[3]); }
+         };
+
+         template <typename T_>
+         struct invoke<T_,3>
+         {
+            static inline T_ execute(ifunction& f, T_ (&v)[3])
+            { return f(v[0],v[1],v[2]); }
+         };
+
+         template <typename T_>
+         struct invoke<T_,2>
+         {
+            static inline T_ execute(ifunction& f, T_ (&v)[2])
+            { return f(v[0],v[1]); }
+         };
+
+         template <typename T_>
+         struct invoke<T_,1>
+         {
+            static inline T_ execute(ifunction& f, T_ (&v)[1])
+            { return f(v[0]); }
+         };
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_function;
+         }
+
+      private:
+
+         ifunction*  function_;
+         std::size_t parameter_count_;
+         branch_t    branch_[N];
+      };
+
+      template <typename T, typename IFunction>
+      class function_N_node<T,IFunction,0> : public expression_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+         typedef IFunction ifunction;
+
+         explicit function_N_node(ifunction* func)
+         : function_((0 == func->param_count) ? func : reinterpret_cast<ifunction*>(0))
+         {}
+
+         inline bool operator <(const function_N_node<T,IFunction,0>& fn) const
+         {
+            return this < (&fn);
+         }
+
+         inline T value() const
+         {
+            if (function_)
+               return (*function_)();
+            else
+               return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_function;
+         }
+
+      private:
+
+         ifunction* function_;
+      };
+
+      template <typename T, typename VarArgFunction>
+      class vararg_function_node : public expression_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+
+         vararg_function_node(VarArgFunction*  func,
+                              const std::vector<expression_ptr>& arg_list)
+         : function_(func),
+           arg_list_(arg_list)
+         {
+            value_list_.resize(arg_list.size(),std::numeric_limits<T>::quiet_NaN());
+         }
+
+        ~vararg_function_node()
+         {
+            for (std::size_t i = 0; i < arg_list_.size(); ++i)
+            {
+               if (arg_list_[i] && !details::is_variable_node(arg_list_[i]))
+               {
+                  destroy_node(arg_list_[i]);
+               }
+            }
+         }
+
+         inline bool operator <(const vararg_function_node<T,VarArgFunction>& fn) const
+         {
+            return this < (&fn);
+         }
+
+         inline T value() const
+         {
+            if (function_)
+            {
+               populate_value_list();
+               return (*function_)(value_list_);
+            }
+            else
+               return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_vafunction;
+         }
+
+      private:
+
+         inline void populate_value_list() const
+         {
+            for (std::size_t i = 0; i < arg_list_.size(); ++i)
+            {
+               value_list_[i] = arg_list_[i]->value();
+            }
+         }
+
+         VarArgFunction* function_;
+         std::vector<expression_ptr> arg_list_;
+         mutable std::vector<T> value_list_;
+      };
+
+      template <typename T, typename GenericFunction>
+      class generic_function_node : public expression_node<T>
+      {
+      public:
+
+         typedef type_store<T>                         type_store_t;
+         typedef expression_node<T>*                 expression_ptr;
+         typedef variable_node<T>                   variable_node_t;
+         typedef vector_node<T>                       vector_node_t;
+         typedef variable_node_t*               variable_node_ptr_t;
+         typedef vector_node_t*                   vector_node_ptr_t;
+         typedef range_interface<T>               range_interface_t;
+         typedef range_data_type<T>               range_data_type_t;
+         typedef range_pack<T>                              range_t;
+         typedef std::pair<expression_ptr,bool>            branch_t;
+         typedef std::pair<void*,std::size_t>                void_t;
+         typedef std::vector<T>                            tmp_vs_t;
+         typedef std::vector<type_store_t>         typestore_list_t;
+         typedef std::vector<range_data_type_t>        range_list_t;
+
+         generic_function_node(const std::vector<expression_ptr>& arg_list,
+                               GenericFunction* func = (GenericFunction*)(0))
+         : function_(func),
+           arg_list_(arg_list)
+         {}
+
+         virtual ~generic_function_node()
+         {
+            cleanup_branches::execute(branch_);
+         }
+
+         virtual bool init_branches()
+         {
+            expr_as_vec1_store_.resize(arg_list_.size(),T(0)               );
+            typestore_list_    .resize(arg_list_.size(),type_store_t()     );
+            range_list_        .resize(arg_list_.size(),range_data_type_t());
+            branch_            .resize(arg_list_.size(),branch_t((expression_ptr)0,false));
+
+            for (std::size_t i = 0; i < arg_list_.size(); ++i)
+            {
+               type_store_t& ts = typestore_list_[i];
+
+               if (0 == arg_list_[i])
+                  return false;
+               else if (is_ivector_node(arg_list_[i]))
+               {
+                  vector_interface<T>* vi = reinterpret_cast<vector_interface<T>*>(0);
+
+                  if (0 == (vi = dynamic_cast<vector_interface<T>*>(arg_list_[i])))
+                     return false;
+
+                  ts.size = vi->size();
+                  ts.data = vi->vds().data();
+                  ts.type = type_store_t::e_vector;
+                  vi->vec()->vec_holder().set_ref(&ts.vec_data);
+               }
+               #ifndef exprtk_disable_string_capabilities
+               else if (is_generally_string_node(arg_list_[i]))
+               {
+                  string_base_node<T>* sbn = reinterpret_cast<string_base_node<T>*>(0);
+
+                  if (0 == (sbn = dynamic_cast<string_base_node<T>*>(arg_list_[i])))
+                     return false;
+
+                  ts.size = sbn->size();
+                  ts.data = reinterpret_cast<void*>(const_cast<char_ptr>(sbn->base()));
+                  ts.type = type_store_t::e_string;
+
+                  range_list_[i].data      = ts.data;
+                  range_list_[i].size      = ts.size;
+                  range_list_[i].type_size = sizeof(char);
+                  range_list_[i].str_node  = sbn;
+
+                  range_interface_t* ri = reinterpret_cast<range_interface_t*>(0);
+
+                  if (0 == (ri = dynamic_cast<range_interface_t*>(arg_list_[i])))
+                     return false;
+
+                  range_t& rp = ri->range_ref();
+
+                  if (
+                       rp.const_range() &&
+                       is_const_string_range_node(arg_list_[i])
+                     )
+                  {
+                     ts.size = rp.const_size();
+                     ts.data = static_cast<char_ptr>(ts.data) + rp.n0_c.second;
+                     range_list_[i].range = reinterpret_cast<range_t*>(0);
+                  }
+                  else
+                     range_list_[i].range = &(ri->range_ref());
+               }
+               #endif
+               else if (is_variable_node(arg_list_[i]))
+               {
+                  variable_node_ptr_t var = variable_node_ptr_t(0);
+
+                  if (0 == (var = dynamic_cast<variable_node_ptr_t>(arg_list_[i])))
+                     return false;
+
+                  ts.size = 1;
+                  ts.data = &var->ref();
+                  ts.type = type_store_t::e_scalar;
+               }
+               else
+               {
+                  ts.size = 1;
+                  ts.data = reinterpret_cast<void*>(&expr_as_vec1_store_[i]);
+                  ts.type = type_store_t::e_scalar;
+               }
+
+               branch_[i] = std::make_pair(arg_list_[i],branch_deletable(arg_list_[i]));
+            }
+
+            return true;
+         }
+
+         inline bool operator <(const generic_function_node<T,GenericFunction>& fn) const
+         {
+            return this < (&fn);
+         }
+
+         inline T value() const
+         {
+            if (function_)
+            {
+               if (populate_value_list())
+               {
+                  typedef typename GenericFunction::parameter_list_t parameter_list_t;
+
+                  return (*function_)(parameter_list_t(typestore_list_));
+               }
+            }
+
+            return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_genfunction;
+         }
+
+      protected:
+
+         inline virtual bool populate_value_list() const
+         {
+            for (std::size_t i = 0; i < branch_.size(); ++i)
+            {
+               expr_as_vec1_store_[i] = branch_[i].first->value();
+            }
+
+            for (std::size_t i = 0; i < branch_.size(); ++i)
+            {
+               range_data_type_t& rdt = range_list_[i];
+
+               if (rdt.range)
+               {
+                  range_t&    rp = (*rdt.range);
+                  std::size_t r0 = 0;
+                  std::size_t r1 = 0;
+
+                  if (rp(r0,r1,rdt.size))
+                  {
+                     type_store_t& ts = typestore_list_[i];
+
+                     ts.size = rp.cache_size();
+                     #ifndef exprtk_disable_string_capabilities
+                     if (ts.type == type_store_t::e_string)
+                        ts.data = const_cast<char_ptr>(rdt.str_node->base()) + rp.cache.first;
+                     else
+                     #endif
+                        ts.data = static_cast<char_ptr>(rdt.data) + (rp.cache.first * rdt.type_size);
+                  }
+                  else
+                     return false;
+               }
+            }
+
+            return true;
+         }
+
+         GenericFunction* function_;
+         mutable typestore_list_t typestore_list_;
+
+      private:
+
+         std::vector<expression_ptr> arg_list_;
+         std::vector<branch_t>         branch_;
+         mutable tmp_vs_t  expr_as_vec1_store_;
+         mutable range_list_t      range_list_;
+      };
+
+      #ifndef exprtk_disable_string_capabilities
+      template <typename T, typename StringFunction>
+      class string_function_node : public generic_function_node<T,StringFunction>,
+                                   public string_base_node<T>,
+                                   public range_interface <T>
+      {
+      public:
+
+         typedef generic_function_node<T,StringFunction> gen_function_t;
+         typedef range_pack<T> range_t;
+
+         string_function_node(StringFunction* func,
+                              const std::vector<typename gen_function_t::expression_ptr>& arg_list)
+         : gen_function_t(arg_list,func)
+         {
+            range_.n0_c = std::make_pair<bool,std::size_t>(true,0);
+            range_.n1_c = std::make_pair<bool,std::size_t>(true,0);
+            range_.cache.first  = range_.n0_c.second;
+            range_.cache.second = range_.n1_c.second;
+         }
+
+         inline bool operator <(const string_function_node<T,StringFunction>& fn) const
+         {
+            return this < (&fn);
+         }
+
+         inline T value() const
+         {
+            if (gen_function_t::function_)
+            {
+               if (gen_function_t::populate_value_list())
+               {
+                  typedef typename StringFunction::parameter_list_t parameter_list_t;
+
+                  const T result = (*gen_function_t::function_)
+                                      (
+                                        ret_string_,
+                                        parameter_list_t(gen_function_t::typestore_list_)
+                                      );
+
+                  range_.n1_c.second  = ret_string_.size() - 1;
+                  range_.cache.second = range_.n1_c.second;
+
+                  return result;
+               }
+            }
+
+            return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_strfunction;
+         }
+
+         std::string str() const
+         {
+            return ret_string_;
+         }
+
+         char_cptr base() const
+         {
+           return &ret_string_[0];
+         }
+
+         std::size_t size() const
+         {
+            return ret_string_.size();
+         }
+
+         range_t& range_ref()
+         {
+            return range_;
+         }
+
+         const range_t& range_ref() const
+         {
+            return range_;
+         }
+
+      protected:
+
+         mutable range_t     range_;
+         mutable std::string ret_string_;
+      };
+      #endif
+
+      template <typename T, typename GenericFunction>
+      class multimode_genfunction_node : public generic_function_node<T,GenericFunction>
+      {
+      public:
+
+         typedef generic_function_node<T,GenericFunction> gen_function_t;
+         typedef range_pack<T> range_t;
+
+         multimode_genfunction_node(GenericFunction* func,
+                                    const std::size_t& param_seq_index,
+                                    const std::vector<typename gen_function_t::expression_ptr>& arg_list)
+         : gen_function_t(arg_list,func),
+           param_seq_index_(param_seq_index)
+         {}
+
+         inline T value() const
+         {
+            if (gen_function_t::function_)
+            {
+               if (gen_function_t::populate_value_list())
+               {
+                  typedef typename GenericFunction::parameter_list_t parameter_list_t;
+
+                  return (*gen_function_t::function_)
+                            (
+                              param_seq_index_,
+                              parameter_list_t(gen_function_t::typestore_list_)
+                            );
+               }
+            }
+
+            return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_genfunction;
+         }
+
+      private:
+
+         std::size_t param_seq_index_;
+      };
+
+      #ifndef exprtk_disable_string_capabilities
+      template <typename T, typename StringFunction>
+      class multimode_strfunction_node : public string_function_node<T,StringFunction>
+      {
+      public:
+
+         typedef string_function_node<T,StringFunction> str_function_t;
+         typedef range_pack<T> range_t;
+
+         multimode_strfunction_node(StringFunction* func,
+                                    const std::size_t& param_seq_index,
+                                    const std::vector<typename str_function_t::expression_ptr>& arg_list)
+         : str_function_t(func,arg_list),
+           param_seq_index_(param_seq_index)
+         {}
+
+         inline T value() const
+         {
+            if (str_function_t::function_)
+            {
+               if (str_function_t::populate_value_list())
+               {
+                  typedef typename StringFunction::parameter_list_t parameter_list_t;
+
+                  const T result = (*str_function_t::function_)
+                                      (
+                                        param_seq_index_,
+                                        str_function_t::ret_string_,
+                                        parameter_list_t(str_function_t::typestore_list_)
+                                      );
+
+                  str_function_t::range_.n1_c.second  = str_function_t::ret_string_.size() - 1;
+                  str_function_t::range_.cache.second = str_function_t::range_.n1_c.second;
+
+                  return result;
+               }
+            }
+
+            return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_strfunction;
+         }
+
+      private:
+
+         const std::size_t param_seq_index_;
+      };
+      #endif
+
+      class return_exception
+      {};
+
+      template <typename T>
+      class null_igenfunc
+      {
+      public:
+
+         virtual ~null_igenfunc()
+         {}
+
+         typedef type_store<T> generic_type;
+         typedef typename generic_type::parameter_list parameter_list_t;
+
+         inline virtual T operator() (parameter_list_t)
+         {
+            return std::numeric_limits<T>::quiet_NaN();
+         }
+      };
+
+      #ifndef exprtk_disable_return_statement
+      template <typename T>
+      class return_node : public generic_function_node<T,null_igenfunc<T> >
+      {
+      public:
+
+         typedef null_igenfunc<T> igeneric_function_t;
+         typedef igeneric_function_t* igeneric_function_ptr;
+         typedef generic_function_node<T,igeneric_function_t> gen_function_t;
+         typedef results_context<T> results_context_t;
+
+         return_node(const std::vector<typename gen_function_t::expression_ptr>& arg_list,
+                     results_context_t& rc)
+         : gen_function_t  (arg_list),
+           results_context_(&rc)
+         {}
+
+         inline T value() const
+         {
+            if (
+                 (0 != results_context_) &&
+                 gen_function_t::populate_value_list()
+               )
+            {
+               typedef typename type_store<T>::parameter_list parameter_list_t;
+
+               results_context_->
+                  assign(parameter_list_t(gen_function_t::typestore_list_));
+
+               throw return_exception();
+            }
+
+            return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_return;
+         }
+
+      private:
+
+         results_context_t* results_context_;
+      };
+
+      template <typename T>
+      class return_envelope_node : public expression_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+         typedef results_context<T>  results_context_t;
+
+         return_envelope_node(expression_ptr body, results_context_t& rc)
+         : results_context_(&rc  ),
+           return_invoked_ (false),
+           body_           (body ),
+           body_deletable_ (branch_deletable(body_))
+         {}
+
+        ~return_envelope_node()
+         {
+            if (body_ && body_deletable_)
+            {
+               destroy_node(body_);
+            }
+         }
+
+         inline T value() const
+         {
+            try
+            {
+               return_invoked_ = false;
+               results_context_->clear();
+
+               return body_->value();
+            }
+            catch(const return_exception&)
+            {
+               return_invoked_ = true;
+               return std::numeric_limits<T>::quiet_NaN();
+            }
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_retenv;
+         }
+
+         inline bool* retinvk_ptr()
+         {
+            return &return_invoked_;
+         }
+
+      private:
+
+         results_context_t* results_context_;
+         mutable bool       return_invoked_;
+         expression_ptr     body_;
+         const bool         body_deletable_;
+      };
+      #endif
+
+      #define exprtk_define_unary_op(OpName)                    \
+      template <typename T>                                     \
+      struct OpName##_op                                        \
+      {                                                         \
+         typedef typename functor_t<T>::Type Type;              \
+         typedef typename expression_node<T>::node_type node_t; \
+                                                                \
+         static inline T process(Type v)                        \
+         {                                                      \
+            return numeric:: OpName (v);                        \
+         }                                                      \
+                                                                \
+         static inline node_t type()                            \
+         {                                                      \
+            return expression_node<T>::e_##OpName;              \
+         }                                                      \
+                                                                \
+         static inline details::operator_type operation()       \
+         {                                                      \
+            return details::e_##OpName;                         \
+         }                                                      \
+      };                                                        \
+
+      exprtk_define_unary_op(abs  )
+      exprtk_define_unary_op(acos )
+      exprtk_define_unary_op(acosh)
+      exprtk_define_unary_op(asin )
+      exprtk_define_unary_op(asinh)
+      exprtk_define_unary_op(atan )
+      exprtk_define_unary_op(atanh)
+      exprtk_define_unary_op(ceil )
+      exprtk_define_unary_op(cos  )
+      exprtk_define_unary_op(cosh )
+      exprtk_define_unary_op(cot  )
+      exprtk_define_unary_op(csc  )
+      exprtk_define_unary_op(d2g  )
+      exprtk_define_unary_op(d2r  )
+      exprtk_define_unary_op(erf  )
+      exprtk_define_unary_op(erfc )
+      exprtk_define_unary_op(exp  )
+      exprtk_define_unary_op(expm1)
+      exprtk_define_unary_op(floor)
+      exprtk_define_unary_op(frac )
+      exprtk_define_unary_op(g2d  )
+      exprtk_define_unary_op(log  )
+      exprtk_define_unary_op(log10)
+      exprtk_define_unary_op(log2 )
+      exprtk_define_unary_op(log1p)
+      exprtk_define_unary_op(ncdf )
+      exprtk_define_unary_op(neg  )
+      exprtk_define_unary_op(notl )
+      exprtk_define_unary_op(pos  )
+      exprtk_define_unary_op(r2d  )
+      exprtk_define_unary_op(round)
+      exprtk_define_unary_op(sec  )
+      exprtk_define_unary_op(sgn  )
+      exprtk_define_unary_op(sin  )
+      exprtk_define_unary_op(sinc )
+      exprtk_define_unary_op(sinh )
+      exprtk_define_unary_op(sqrt )
+      exprtk_define_unary_op(tan  )
+      exprtk_define_unary_op(tanh )
+      exprtk_define_unary_op(trunc)
+      #undef exprtk_define_unary_op
+
+      template <typename T>
+      struct opr_base
+      {
+         typedef typename details::functor_t<T>::Type    Type;
+         typedef typename details::functor_t<T>::RefType RefType;
+         typedef typename details::functor_t<T>          functor_t;
+         typedef typename functor_t::qfunc_t  quaternary_functor_t;
+         typedef typename functor_t::tfunc_t     trinary_functor_t;
+         typedef typename functor_t::bfunc_t      binary_functor_t;
+         typedef typename functor_t::ufunc_t       unary_functor_t;
+      };
+
+      template <typename T>
+      struct add_op : public opr_base<T>
+      {
+         typedef typename opr_base<T>::Type    Type;
+         typedef typename opr_base<T>::RefType RefType;
+
+         static inline T process(Type t1, Type t2) { return t1 + t2; }
+         static inline T process(Type t1, Type t2, Type t3) { return t1 + t2 + t3; }
+         static inline void assign(RefType t1, Type t2) { t1 += t2; }
+         static inline typename expression_node<T>::node_type type() { return expression_node<T>::e_add; }
+         static inline details::operator_type operation() { return details::e_add; }
+      };
+
+      template <typename T>
+      struct mul_op : public opr_base<T>
+      {
+         typedef typename opr_base<T>::Type    Type;
+         typedef typename opr_base<T>::RefType RefType;
+
+         static inline T process(Type t1, Type t2) { return t1 * t2; }
+         static inline T process(Type t1, Type t2, Type t3) { return t1 * t2 * t3; }
+         static inline void assign(RefType t1, Type t2) { t1 *= t2; }
+         static inline typename expression_node<T>::node_type type() { return expression_node<T>::e_mul; }
+         static inline details::operator_type operation() { return details::e_mul; }
+      };
+
+      template <typename T>
+      struct sub_op : public opr_base<T>
+      {
+         typedef typename opr_base<T>::Type    Type;
+         typedef typename opr_base<T>::RefType RefType;
+
+         static inline T process(Type t1, Type t2) { return t1 - t2; }
+         static inline T process(Type t1, Type t2, Type t3) { return t1 - t2 - t3; }
+         static inline void assign(RefType t1, Type t2) { t1 -= t2; }
+         static inline typename expression_node<T>::node_type type() { return expression_node<T>::e_sub; }
+         static inline details::operator_type operation() { return details::e_sub; }
+      };
+
+      template <typename T>
+      struct div_op : public opr_base<T>
+      {
+         typedef typename opr_base<T>::Type    Type;
+         typedef typename opr_base<T>::RefType RefType;
+
+         static inline T process(Type t1, Type t2) { return t1 / t2; }
+         static inline T process(Type t1, Type t2, Type t3) { return t1 / t2 / t3; }
+         static inline void assign(RefType t1, Type t2) { t1 /= t2; }
+         static inline typename expression_node<T>::node_type type() { return expression_node<T>::e_div; }
+         static inline details::operator_type operation() { return details::e_div; }
+      };
+
+      template <typename T>
+      struct mod_op : public opr_base<T>
+      {
+         typedef typename opr_base<T>::Type    Type;
+         typedef typename opr_base<T>::RefType RefType;
+
+         static inline T process(Type t1, Type t2) { return numeric::modulus<T>(t1,t2); }
+         static inline void assign(RefType t1, Type t2) { t1 = numeric::modulus<T>(t1,t2); }
+         static inline typename expression_node<T>::node_type type() { return expression_node<T>::e_mod; }
+         static inline details::operator_type operation() { return details::e_mod; }
+      };
+
+      template <typename T>
+      struct pow_op : public opr_base<T>
+      {
+         typedef typename opr_base<T>::Type    Type;
+         typedef typename opr_base<T>::RefType RefType;
+
+         static inline T process(Type t1, Type t2) { return numeric::pow<T>(t1,t2); }
+         static inline void assign(RefType t1, Type t2) { t1 = numeric::pow<T>(t1,t2); }
+         static inline typename expression_node<T>::node_type type() { return expression_node<T>::e_pow; }
+         static inline details::operator_type operation() { return details::e_pow; }
+      };
+
+      template <typename T>
+      struct lt_op : public opr_base<T>
+      {
+         typedef typename opr_base<T>::Type Type;
+
+         static inline T process(Type t1, Type t2) { return ((t1 < t2) ? T(1) : T(0)); }
+         static inline T process(const std::string& t1, const std::string& t2) { return ((t1 < t2) ? T(1) : T(0)); }
+         static inline typename expression_node<T>::node_type type() { return expression_node<T>::e_lt; }
+         static inline details::operator_type operation() { return details::e_lt; }
+      };
+
+      template <typename T>
+      struct lte_op : public opr_base<T>
+      {
+         typedef typename opr_base<T>::Type Type;
+
+         static inline T process(Type t1, Type t2) { return ((t1 <= t2) ? T(1) : T(0)); }
+         static inline T process(const std::string& t1, const std::string& t2) { return ((t1 <= t2) ? T(1) : T(0)); }
+         static inline typename expression_node<T>::node_type type() { return expression_node<T>::e_lte; }
+         static inline details::operator_type operation() { return details::e_lte; }
+      };
+
+      template <typename T>
+      struct gt_op : public opr_base<T>
+      {
+         typedef typename opr_base<T>::Type Type;
+
+         static inline T process(Type t1, Type t2) { return ((t1 > t2) ? T(1) : T(0)); }
+         static inline T process(const std::string& t1, const std::string& t2) { return ((t1 > t2) ? T(1) : T(0)); }
+         static inline typename expression_node<T>::node_type type() { return expression_node<T>::e_gt; }
+         static inline details::operator_type operation() { return details::e_gt; }
+      };
+
+      template <typename T>
+      struct gte_op : public opr_base<T>
+      {
+         typedef typename opr_base<T>::Type Type;
+
+         static inline T process(Type t1, Type t2) { return ((t1 >= t2) ? T(1) : T(0)); }
+         static inline T process(const std::string& t1, const std::string& t2) { return ((t1 >= t2) ? T(1) : T(0)); }
+         static inline typename expression_node<T>::node_type type() { return expression_node<T>::e_gte; }
+         static inline details::operator_type operation() { return details::e_gte; }
+      };
+
+      template <typename T>
+      struct eq_op : public opr_base<T>
+      {
+         typedef typename opr_base<T>::Type Type;
+         static inline T process(Type t1, Type t2) { return (std::equal_to<T>()(t1,t2) ? T(1) : T(0)); }
+         static inline T process(const std::string& t1, const std::string& t2) { return ((t1 == t2) ? T(1) : T(0)); }
+         static inline typename expression_node<T>::node_type type() { return expression_node<T>::e_eq; }
+         static inline details::operator_type operation() { return details::e_eq; }
+      };
+
+      template <typename T>
+      struct equal_op : public opr_base<T>
+      {
+         typedef typename opr_base<T>::Type Type;
+
+         static inline T process(Type t1, Type t2) { return numeric::equal(t1,t2); }
+         static inline T process(const std::string& t1, const std::string& t2) { return ((t1 == t2) ? T(1) : T(0)); }
+         static inline typename expression_node<T>::node_type type() { return expression_node<T>::e_eq; }
+         static inline details::operator_type operation() { return details::e_equal; }
+      };
+
+      template <typename T>
+      struct ne_op : public opr_base<T>
+      {
+         typedef typename opr_base<T>::Type Type;
+
+         static inline T process(Type t1, Type t2) { return (std::not_equal_to<T>()(t1,t2) ? T(1) : T(0)); }
+         static inline T process(const std::string& t1, const std::string& t2) { return ((t1 != t2) ? T(1) : T(0)); }
+         static inline typename expression_node<T>::node_type type() { return expression_node<T>::e_ne; }
+         static inline details::operator_type operation() { return details::e_ne; }
+      };
+
+      template <typename T>
+      struct and_op : public opr_base<T>
+      {
+         typedef typename opr_base<T>::Type Type;
+
+         static inline T process(Type t1, Type t2) { return (details::is_true(t1) && details::is_true(t2)) ? T(1) : T(0); }
+         static inline typename expression_node<T>::node_type type() { return expression_node<T>::e_and; }
+         static inline details::operator_type operation() { return details::e_and; }
+      };
+
+      template <typename T>
+      struct nand_op : public opr_base<T>
+      {
+         typedef typename opr_base<T>::Type Type;
+
+         static inline T process(Type t1, Type t2) { return (details::is_true(t1) && details::is_true(t2)) ? T(0) : T(1); }
+         static inline typename expression_node<T>::node_type type() { return expression_node<T>::e_nand; }
+         static inline details::operator_type operation() { return details::e_nand; }
+      };
+
+      template <typename T>
+      struct or_op : public opr_base<T>
+      {
+         typedef typename opr_base<T>::Type Type;
+
+         static inline T process(Type t1, Type t2) { return (details::is_true(t1) || details::is_true(t2)) ? T(1) : T(0); }
+         static inline typename expression_node<T>::node_type type() { return expression_node<T>::e_or; }
+         static inline details::operator_type operation() { return details::e_or; }
+      };
+
+      template <typename T>
+      struct nor_op : public opr_base<T>
+      {
+         typedef typename opr_base<T>::Type Type;
+
+         static inline T process(Type t1, Type t2) { return (details::is_true(t1) || details::is_true(t2)) ? T(0) : T(1); }
+         static inline typename expression_node<T>::node_type type() { return expression_node<T>::e_nor; }
+         static inline details::operator_type operation() { return details::e_nor; }
+      };
+
+      template <typename T>
+      struct xor_op : public opr_base<T>
+      {
+         typedef typename opr_base<T>::Type Type;
+
+         static inline T process(Type t1, Type t2) { return numeric::xor_opr<T>(t1,t2); }
+         static inline typename expression_node<T>::node_type type() { return expression_node<T>::e_nor; }
+         static inline details::operator_type operation() { return details::e_xor; }
+      };
+
+      template <typename T>
+      struct xnor_op : public opr_base<T>
+      {
+         typedef typename opr_base<T>::Type Type;
+
+         static inline T process(Type t1, Type t2) { return numeric::xnor_opr<T>(t1,t2); }
+         static inline typename expression_node<T>::node_type type() { return expression_node<T>::e_nor; }
+         static inline details::operator_type operation() { return details::e_xnor; }
+      };
+
+      template <typename T>
+      struct in_op : public opr_base<T>
+      {
+         typedef typename opr_base<T>::Type Type;
+
+         static inline T process(const T&, const T&) { return std::numeric_limits<T>::quiet_NaN(); }
+         static inline T process(const std::string& t1, const std::string& t2) { return ((std::string::npos != t2.find(t1)) ? T(1) : T(0)); }
+         static inline typename expression_node<T>::node_type type() { return expression_node<T>::e_in; }
+         static inline details::operator_type operation() { return details::e_in; }
+      };
+
+      template <typename T>
+      struct like_op : public opr_base<T>
+      {
+         typedef typename opr_base<T>::Type Type;
+
+         static inline T process(const T&, const T&) { return std::numeric_limits<T>::quiet_NaN(); }
+         static inline T process(const std::string& t1, const std::string& t2) { return (details::wc_match(t2,t1) ? T(1) : T(0)); }
+         static inline typename expression_node<T>::node_type type() { return expression_node<T>::e_like; }
+         static inline details::operator_type operation() { return details::e_like; }
+      };
+
+      template <typename T>
+      struct ilike_op : public opr_base<T>
+      {
+         typedef typename opr_base<T>::Type Type;
+
+         static inline T process(const T&, const T&) { return std::numeric_limits<T>::quiet_NaN(); }
+         static inline T process(const std::string& t1, const std::string& t2) { return (details::wc_imatch(t2,t1) ? T(1) : T(0)); }
+         static inline typename expression_node<T>::node_type type() { return expression_node<T>::e_ilike; }
+         static inline details::operator_type operation() { return details::e_ilike; }
+      };
+
+      template <typename T>
+      struct inrange_op : public opr_base<T>
+      {
+         typedef typename opr_base<T>::Type Type;
+
+         static inline T process(const T& t0, const T& t1, const T& t2) { return ((t0 <= t1) && (t1 <= t2)) ? T(1) : T(0); }
+         static inline T process(const std::string& t0, const std::string& t1, const std::string& t2)
+         {
+            return ((t0 <= t1) && (t1 <= t2)) ? T(1) : T(0);
+         }
+         static inline typename expression_node<T>::node_type type() { return expression_node<T>::e_inranges; }
+         static inline details::operator_type operation() { return details::e_inrange; }
+      };
+
+      template <typename T>
+      inline T value(details::expression_node<T>* n)
+      {
+         return n->value();
+      }
+
+      template <typename T>
+      inline T value(T* t)
+      {
+         return (*t);
+      }
+
+      template <typename T>
+      struct vararg_add_op : public opr_base<T>
+      {
+         typedef typename opr_base<T>::Type Type;
+
+         template <typename Type,
+                   typename Allocator,
+                   template <typename, typename> class Sequence>
+         static inline T process(const Sequence<Type,Allocator>& arg_list)
+         {
+            switch (arg_list.size())
+            {
+               case 0  : return T(0);
+               case 1  : return process_1(arg_list);
+               case 2  : return process_2(arg_list);
+               case 3  : return process_3(arg_list);
+               case 4  : return process_4(arg_list);
+               case 5  : return process_5(arg_list);
+               default :
+                         {
+                            T result = T(0);
+
+                            for (std::size_t i = 0; i < arg_list.size(); ++i)
+                            {
+                              result += value(arg_list[i]);
+                            }
+
+                            return result;
+                         }
+            }
+         }
+
+         template <typename Sequence>
+         static inline T process_1(const Sequence& arg_list)
+         {
+            return value(arg_list[0]);
+         }
+
+         template <typename Sequence>
+         static inline T process_2(const Sequence& arg_list)
+         {
+            return value(arg_list[0]) + value(arg_list[1]);
+         }
+
+         template <typename Sequence>
+         static inline T process_3(const Sequence& arg_list)
+         {
+            return value(arg_list[0]) + value(arg_list[1]) +
+                   value(arg_list[2]) ;
+         }
+
+         template <typename Sequence>
+         static inline T process_4(const Sequence& arg_list)
+         {
+            return value(arg_list[0]) + value(arg_list[1]) +
+                   value(arg_list[2]) + value(arg_list[3]) ;
+         }
+
+         template <typename Sequence>
+         static inline T process_5(const Sequence& arg_list)
+         {
+            return value(arg_list[0]) + value(arg_list[1]) +
+                   value(arg_list[2]) + value(arg_list[3]) +
+                   value(arg_list[4]) ;
+         }
+      };
+
+      template <typename T>
+      struct vararg_mul_op : public opr_base<T>
+      {
+         typedef typename opr_base<T>::Type Type;
+
+         template <typename Type,
+                   typename Allocator,
+                   template <typename, typename> class Sequence>
+         static inline T process(const Sequence<Type,Allocator>& arg_list)
+         {
+            switch (arg_list.size())
+            {
+               case 0  : return T(0);
+               case 1  : return process_1(arg_list);
+               case 2  : return process_2(arg_list);
+               case 3  : return process_3(arg_list);
+               case 4  : return process_4(arg_list);
+               case 5  : return process_5(arg_list);
+               default :
+                         {
+                            T result = T(value(arg_list[0]));
+
+                            for (std::size_t i = 1; i < arg_list.size(); ++i)
+                            {
+                               result *= value(arg_list[i]);
+                            }
+
+                            return result;
+                         }
+            }
+         }
+
+         template <typename Sequence>
+         static inline T process_1(const Sequence& arg_list)
+         {
+            return value(arg_list[0]);
+         }
+
+         template <typename Sequence>
+         static inline T process_2(const Sequence& arg_list)
+         {
+            return value(arg_list[0]) * value(arg_list[1]);
+         }
+
+         template <typename Sequence>
+         static inline T process_3(const Sequence& arg_list)
+         {
+            return value(arg_list[0]) * value(arg_list[1]) *
+                   value(arg_list[2]) ;
+         }
+
+         template <typename Sequence>
+         static inline T process_4(const Sequence& arg_list)
+         {
+            return value(arg_list[0]) * value(arg_list[1]) *
+                   value(arg_list[2]) * value(arg_list[3]) ;
+         }
+
+         template <typename Sequence>
+         static inline T process_5(const Sequence& arg_list)
+         {
+            return value(arg_list[0]) * value(arg_list[1]) *
+                   value(arg_list[2]) * value(arg_list[3]) *
+                   value(arg_list[4]) ;
+         }
+      };
+
+      template <typename T>
+      struct vararg_avg_op : public opr_base<T>
+      {
+         typedef typename opr_base<T>::Type Type;
+
+         template <typename Type,
+                   typename Allocator,
+                   template <typename, typename> class Sequence>
+         static inline T process(const Sequence<Type,Allocator>& arg_list)
+         {
+            switch (arg_list.size())
+            {
+               case 0  : return T(0);
+               case 1  : return process_1(arg_list);
+               case 2  : return process_2(arg_list);
+               case 3  : return process_3(arg_list);
+               case 4  : return process_4(arg_list);
+               case 5  : return process_5(arg_list);
+               default : return vararg_add_op<T>::process(arg_list) / arg_list.size();
+            }
+         }
+
+         template <typename Sequence>
+         static inline T process_1(const Sequence& arg_list)
+         {
+            return value(arg_list[0]);
+         }
+
+         template <typename Sequence>
+         static inline T process_2(const Sequence& arg_list)
+         {
+            return (value(arg_list[0]) + value(arg_list[1])) / T(2);
+         }
+
+         template <typename Sequence>
+         static inline T process_3(const Sequence& arg_list)
+         {
+            return (value(arg_list[0]) + value(arg_list[1]) + value(arg_list[2])) / T(3);
+         }
+
+         template <typename Sequence>
+         static inline T process_4(const Sequence& arg_list)
+         {
+            return (value(arg_list[0]) + value(arg_list[1]) +
+                    value(arg_list[2]) + value(arg_list[3])) / T(4);
+         }
+
+         template <typename Sequence>
+         static inline T process_5(const Sequence& arg_list)
+         {
+            return (value(arg_list[0]) + value(arg_list[1]) +
+                    value(arg_list[2]) + value(arg_list[3]) +
+                    value(arg_list[4])) / T(5);
+         }
+      };
+
+      template <typename T>
+      struct vararg_min_op : public opr_base<T>
+      {
+         typedef typename opr_base<T>::Type Type;
+
+         template <typename Type,
+                   typename Allocator,
+                   template <typename, typename> class Sequence>
+         static inline T process(const Sequence<Type,Allocator>& arg_list)
+         {
+            switch (arg_list.size())
+            {
+               case 0  : return T(0);
+               case 1  : return process_1(arg_list);
+               case 2  : return process_2(arg_list);
+               case 3  : return process_3(arg_list);
+               case 4  : return process_4(arg_list);
+               case 5  : return process_5(arg_list);
+               default :
+                         {
+                            T result = T(value(arg_list[0]));
+
+                            for (std::size_t i = 1; i < arg_list.size(); ++i)
+                            {
+                               const T v = value(arg_list[i]);
+
+                               if (v < result)
+                                  result = v;
+                            }
+
+                            return result;
+                         }
+            }
+         }
+
+         template <typename Sequence>
+         static inline T process_1(const Sequence& arg_list)
+         {
+            return value(arg_list[0]);
+         }
+
+         template <typename Sequence>
+         static inline T process_2(const Sequence& arg_list)
+         {
+            return std::min<T>(value(arg_list[0]),value(arg_list[1]));
+         }
+
+         template <typename Sequence>
+         static inline T process_3(const Sequence& arg_list)
+         {
+            return std::min<T>(std::min<T>(value(arg_list[0]),value(arg_list[1])),value(arg_list[2]));
+         }
+
+         template <typename Sequence>
+         static inline T process_4(const Sequence& arg_list)
+         {
+            return std::min<T>(
+                        std::min<T>(value(arg_list[0]), value(arg_list[1])),
+                        std::min<T>(value(arg_list[2]), value(arg_list[3])));
+         }
+
+         template <typename Sequence>
+         static inline T process_5(const Sequence& arg_list)
+         {
+            return std::min<T>(
+                   std::min<T>(std::min<T>(value(arg_list[0]), value(arg_list[1])),
+                               std::min<T>(value(arg_list[2]), value(arg_list[3]))),
+                               value(arg_list[4]));
+         }
+      };
+
+      template <typename T>
+      struct vararg_max_op : public opr_base<T>
+      {
+         typedef typename opr_base<T>::Type Type;
+
+         template <typename Type,
+                   typename Allocator,
+                   template <typename, typename> class Sequence>
+         static inline T process(const Sequence<Type,Allocator>& arg_list)
+         {
+            switch (arg_list.size())
+            {
+               case 0  : return T(0);
+               case 1  : return process_1(arg_list);
+               case 2  : return process_2(arg_list);
+               case 3  : return process_3(arg_list);
+               case 4  : return process_4(arg_list);
+               case 5  : return process_5(arg_list);
+               default :
+                         {
+                            T result = T(value(arg_list[0]));
+
+                            for (std::size_t i = 1; i < arg_list.size(); ++i)
+                            {
+                               const T v = value(arg_list[i]);
+
+                               if (v > result)
+                                  result = v;
+                            }
+
+                            return result;
+                         }
+            }
+         }
+
+         template <typename Sequence>
+         static inline T process_1(const Sequence& arg_list)
+         {
+            return value(arg_list[0]);
+         }
+
+         template <typename Sequence>
+         static inline T process_2(const Sequence& arg_list)
+         {
+            return std::max<T>(value(arg_list[0]),value(arg_list[1]));
+         }
+
+         template <typename Sequence>
+         static inline T process_3(const Sequence& arg_list)
+         {
+            return std::max<T>(std::max<T>(value(arg_list[0]),value(arg_list[1])),value(arg_list[2]));
+         }
+
+         template <typename Sequence>
+         static inline T process_4(const Sequence& arg_list)
+         {
+            return std::max<T>(
+                        std::max<T>(value(arg_list[0]), value(arg_list[1])),
+                        std::max<T>(value(arg_list[2]), value(arg_list[3])));
+         }
+
+         template <typename Sequence>
+         static inline T process_5(const Sequence& arg_list)
+         {
+            return std::max<T>(
+                   std::max<T>(std::max<T>(value(arg_list[0]), value(arg_list[1])),
+                               std::max<T>(value(arg_list[2]), value(arg_list[3]))),
+                               value(arg_list[4]));
+         }
+      };
+
+      template <typename T>
+      struct vararg_mand_op : public opr_base<T>
+      {
+         typedef typename opr_base<T>::Type Type;
+
+         template <typename Type,
+                   typename Allocator,
+                   template <typename, typename> class Sequence>
+         static inline T process(const Sequence<Type,Allocator>& arg_list)
+         {
+            switch (arg_list.size())
+            {
+               case 1  : return process_1(arg_list);
+               case 2  : return process_2(arg_list);
+               case 3  : return process_3(arg_list);
+               case 4  : return process_4(arg_list);
+               case 5  : return process_5(arg_list);
+               default :
+                         {
+                            for (std::size_t i = 0; i < arg_list.size(); ++i)
+                            {
+                               if (std::equal_to<T>()(T(0), value(arg_list[i])))
+                                  return T(0);
+                            }
+
+                            return T(1);
+                         }
+            }
+         }
+
+         template <typename Sequence>
+         static inline T process_1(const Sequence& arg_list)
+         {
+            return std::not_equal_to<T>()
+                      (T(0), value(arg_list[0])) ? T(1) : T(0);
+         }
+
+         template <typename Sequence>
+         static inline T process_2(const Sequence& arg_list)
+         {
+            return (
+                     std::not_equal_to<T>()(T(0), value(arg_list[0])) &&
+                     std::not_equal_to<T>()(T(0), value(arg_list[1]))
+                   ) ? T(1) : T(0);
+         }
+
+         template <typename Sequence>
+         static inline T process_3(const Sequence& arg_list)
+         {
+            return (
+                     std::not_equal_to<T>()(T(0), value(arg_list[0])) &&
+                     std::not_equal_to<T>()(T(0), value(arg_list[1])) &&
+                     std::not_equal_to<T>()(T(0), value(arg_list[2]))
+                   ) ? T(1) : T(0);
+         }
+
+         template <typename Sequence>
+         static inline T process_4(const Sequence& arg_list)
+         {
+            return (
+                     std::not_equal_to<T>()(T(0), value(arg_list[0])) &&
+                     std::not_equal_to<T>()(T(0), value(arg_list[1])) &&
+                     std::not_equal_to<T>()(T(0), value(arg_list[2])) &&
+                     std::not_equal_to<T>()(T(0), value(arg_list[3]))
+                   ) ? T(1) : T(0);
+         }
+
+         template <typename Sequence>
+         static inline T process_5(const Sequence& arg_list)
+         {
+            return (
+                     std::not_equal_to<T>()(T(0), value(arg_list[0])) &&
+                     std::not_equal_to<T>()(T(0), value(arg_list[1])) &&
+                     std::not_equal_to<T>()(T(0), value(arg_list[2])) &&
+                     std::not_equal_to<T>()(T(0), value(arg_list[3])) &&
+                     std::not_equal_to<T>()(T(0), value(arg_list[4]))
+                   ) ? T(1) : T(0);
+         }
+      };
+
+      template <typename T>
+      struct vararg_mor_op : public opr_base<T>
+      {
+         typedef typename opr_base<T>::Type Type;
+
+         template <typename Type,
+                   typename Allocator,
+                   template <typename, typename> class Sequence>
+         static inline T process(const Sequence<Type,Allocator>& arg_list)
+         {
+            switch (arg_list.size())
+            {
+               case 1  : return process_1(arg_list);
+               case 2  : return process_2(arg_list);
+               case 3  : return process_3(arg_list);
+               case 4  : return process_4(arg_list);
+               case 5  : return process_5(arg_list);
+               default :
+                         {
+                            for (std::size_t i = 0; i < arg_list.size(); ++i)
+                            {
+                               if (std::not_equal_to<T>()(T(0), value(arg_list[i])))
+                                  return T(1);
+                            }
+
+                            return T(0);
+                         }
+            }
+         }
+
+         template <typename Sequence>
+         static inline T process_1(const Sequence& arg_list)
+         {
+            return std::not_equal_to<T>()
+                      (T(0), value(arg_list[0])) ? T(1) : T(0);
+         }
+
+         template <typename Sequence>
+         static inline T process_2(const Sequence& arg_list)
+         {
+            return (
+                     std::not_equal_to<T>()(T(0), value(arg_list[0])) ||
+                     std::not_equal_to<T>()(T(0), value(arg_list[1]))
+                   ) ? T(1) : T(0);
+         }
+
+         template <typename Sequence>
+         static inline T process_3(const Sequence& arg_list)
+         {
+            return (
+                     std::not_equal_to<T>()(T(0), value(arg_list[0])) ||
+                     std::not_equal_to<T>()(T(0), value(arg_list[1])) ||
+                     std::not_equal_to<T>()(T(0), value(arg_list[2]))
+                   ) ? T(1) : T(0);
+         }
+
+         template <typename Sequence>
+         static inline T process_4(const Sequence& arg_list)
+         {
+            return (
+                     std::not_equal_to<T>()(T(0), value(arg_list[0])) ||
+                     std::not_equal_to<T>()(T(0), value(arg_list[1])) ||
+                     std::not_equal_to<T>()(T(0), value(arg_list[2])) ||
+                     std::not_equal_to<T>()(T(0), value(arg_list[3]))
+                   ) ? T(1) : T(0);
+         }
+
+         template <typename Sequence>
+         static inline T process_5(const Sequence& arg_list)
+         {
+            return (
+                     std::not_equal_to<T>()(T(0), value(arg_list[0])) ||
+                     std::not_equal_to<T>()(T(0), value(arg_list[1])) ||
+                     std::not_equal_to<T>()(T(0), value(arg_list[2])) ||
+                     std::not_equal_to<T>()(T(0), value(arg_list[3])) ||
+                     std::not_equal_to<T>()(T(0), value(arg_list[4]))
+                   ) ? T(1) : T(0);
+         }
+      };
+
+      template <typename T>
+      struct vararg_multi_op : public opr_base<T>
+      {
+         typedef typename opr_base<T>::Type Type;
+
+         template <typename Type,
+                   typename Allocator,
+                   template <typename, typename> class Sequence>
+         static inline T process(const Sequence<Type,Allocator>& arg_list)
+         {
+            switch (arg_list.size())
+            {
+               case 0  : return std::numeric_limits<T>::quiet_NaN();
+               case 1  : return process_1(arg_list);
+               case 2  : return process_2(arg_list);
+               case 3  : return process_3(arg_list);
+               case 4  : return process_4(arg_list);
+               case 5  : return process_5(arg_list);
+               case 6  : return process_6(arg_list);
+               case 7  : return process_7(arg_list);
+               case 8  : return process_8(arg_list);
+               default :
+                         {
+                            for (std::size_t i = 0; i < (arg_list.size() - 1); ++i)
+                            {
+                               value(arg_list[i]);
+                            }
+
+                            return value(arg_list.back());
+                         }
+            }
+         }
+
+         template <typename Sequence>
+         static inline T process_1(const Sequence& arg_list)
+         {
+            return value(arg_list[0]);
+         }
+
+         template <typename Sequence>
+         static inline T process_2(const Sequence& arg_list)
+         {
+                   value(arg_list[0]);
+            return value(arg_list[1]);
+         }
+
+         template <typename Sequence>
+         static inline T process_3(const Sequence& arg_list)
+         {
+                   value(arg_list[0]);
+                   value(arg_list[1]);
+            return value(arg_list[2]);
+         }
+
+         template <typename Sequence>
+         static inline T process_4(const Sequence& arg_list)
+         {
+                   value(arg_list[0]);
+                   value(arg_list[1]);
+                   value(arg_list[2]);
+            return value(arg_list[3]);
+         }
+
+         template <typename Sequence>
+         static inline T process_5(const Sequence& arg_list)
+         {
+                   value(arg_list[0]);
+                   value(arg_list[1]);
+                   value(arg_list[2]);
+                   value(arg_list[3]);
+            return value(arg_list[4]);
+         }
+
+         template <typename Sequence>
+         static inline T process_6(const Sequence& arg_list)
+         {
+                   value(arg_list[0]);
+                   value(arg_list[1]);
+                   value(arg_list[2]);
+                   value(arg_list[3]);
+                   value(arg_list[4]);
+            return value(arg_list[5]);
+         }
+
+         template <typename Sequence>
+         static inline T process_7(const Sequence& arg_list)
+         {
+                   value(arg_list[0]);
+                   value(arg_list[1]);
+                   value(arg_list[2]);
+                   value(arg_list[3]);
+                   value(arg_list[4]);
+                   value(arg_list[5]);
+            return value(arg_list[6]);
+         }
+
+         template <typename Sequence>
+         static inline T process_8(const Sequence& arg_list)
+         {
+                   value(arg_list[0]);
+                   value(arg_list[1]);
+                   value(arg_list[2]);
+                   value(arg_list[3]);
+                   value(arg_list[4]);
+                   value(arg_list[5]);
+                   value(arg_list[6]);
+            return value(arg_list[7]);
+         }
+      };
+
+      template <typename T>
+      struct vec_add_op
+      {
+         typedef vector_interface<T>* ivector_ptr;
+
+         static inline T process(const ivector_ptr v)
+         {
+            const T* vec = v->vec()->vds().data();
+            const std::size_t vec_size = v->vec()->vds().size();
+
+            loop_unroll::details lud(vec_size);
+
+            if (vec_size <= static_cast<std::size_t>(lud.batch_size))
+            {
+               T result = T(0);
+               int i    = 0;
+
+               exprtk_disable_fallthrough_begin
+               switch (vec_size)
+               {
+                  #define case_stmt(N)         \
+                  case N : result += vec[i++]; \
+
+                  #ifndef exprtk_disable_superscalar_unroll
+                  case_stmt(16) case_stmt(15)
+                  case_stmt(14) case_stmt(13)
+                  case_stmt(12) case_stmt(11)
+                  case_stmt(10) case_stmt( 9)
+                  case_stmt( 8) case_stmt( 7)
+                  case_stmt( 6) case_stmt( 5)
+                  #endif
+                  case_stmt( 4) case_stmt( 3)
+                  case_stmt( 2) case_stmt( 1)
+               }
+               exprtk_disable_fallthrough_end
+
+               #undef case_stmt
+
+               return result;
+            }
+
+            T r[] = {
+                      T(0), T(0), T(0), T(0), T(0), T(0), T(0), T(0),
+                      T(0), T(0), T(0), T(0), T(0), T(0), T(0), T(0)
+                    };
+
+            const T* upper_bound = vec + lud.upper_bound;
+
+            while (vec < upper_bound)
+            {
+               #define exprtk_loop(N) \
+               r[N] += vec[N];        \
+
+               exprtk_loop( 0) exprtk_loop( 1)
+               exprtk_loop( 2) exprtk_loop( 3)
+               #ifndef exprtk_disable_superscalar_unroll
+               exprtk_loop( 4) exprtk_loop( 5)
+               exprtk_loop( 6) exprtk_loop( 7)
+               exprtk_loop( 8) exprtk_loop( 9)
+               exprtk_loop(10) exprtk_loop(11)
+               exprtk_loop(12) exprtk_loop(13)
+               exprtk_loop(14) exprtk_loop(15)
+               #endif
+
+               vec += lud.batch_size;
+            }
+
+            int i = 0;
+
+            exprtk_disable_fallthrough_begin
+            switch (lud.remainder)
+            {
+               #define case_stmt(N)       \
+               case N : r[0] += vec[i++]; \
+
+               #ifndef exprtk_disable_superscalar_unroll
+               case_stmt(15) case_stmt(14)
+               case_stmt(13) case_stmt(12)
+               case_stmt(11) case_stmt(10)
+               case_stmt( 9) case_stmt( 8)
+               case_stmt( 7) case_stmt( 6)
+               case_stmt( 5) case_stmt( 4)
+               #endif
+               case_stmt( 3) case_stmt( 2)
+               case_stmt( 1)
+            }
+            exprtk_disable_fallthrough_end
+
+            #undef exprtk_loop
+            #undef case_stmt
+
+            return (r[ 0] + r[ 1] + r[ 2] + r[ 3])
+                   #ifndef exprtk_disable_superscalar_unroll
+                 + (r[ 4] + r[ 5] + r[ 6] + r[ 7])
+                 + (r[ 8] + r[ 9] + r[10] + r[11])
+                 + (r[12] + r[13] + r[14] + r[15])
+                   #endif
+                   ;
+         }
+      };
+
+      template <typename T>
+      struct vec_mul_op
+      {
+         typedef vector_interface<T>* ivector_ptr;
+
+         static inline T process(const ivector_ptr v)
+         {
+            const T* vec = v->vec()->vds().data();
+            const std::size_t vec_size = v->vec()->vds().size();
+
+            loop_unroll::details lud(vec_size);
+
+            if (vec_size <= static_cast<std::size_t>(lud.batch_size))
+            {
+               T result = T(1);
+               int i    = 0;
+
+               exprtk_disable_fallthrough_begin
+               switch (vec_size)
+               {
+                  #define case_stmt(N)         \
+                  case N : result *= vec[i++]; \
+
+                  #ifndef exprtk_disable_superscalar_unroll
+                  case_stmt(16) case_stmt(15)
+                  case_stmt(14) case_stmt(13)
+                  case_stmt(12) case_stmt(11)
+                  case_stmt(10) case_stmt( 9)
+                  case_stmt( 8) case_stmt( 7)
+                  case_stmt( 6) case_stmt( 5)
+                  #endif
+                  case_stmt( 4) case_stmt( 3)
+                  case_stmt( 2) case_stmt( 1)
+               }
+               exprtk_disable_fallthrough_end
+
+               #undef case_stmt
+
+               return result;
+            }
+
+            T r[] = {
+                      T(1), T(1), T(1), T(1), T(1), T(1), T(1), T(1),
+                      T(1), T(1), T(1), T(1), T(1), T(1), T(1), T(1)
+                    };
+
+            const T* upper_bound = vec + lud.upper_bound;
+
+            while (vec < upper_bound)
+            {
+               #define exprtk_loop(N) \
+               r[N] *= vec[N];        \
+
+               exprtk_loop( 0) exprtk_loop( 1)
+               exprtk_loop( 2) exprtk_loop( 3)
+               #ifndef exprtk_disable_superscalar_unroll
+               exprtk_loop( 4) exprtk_loop( 5)
+               exprtk_loop( 6) exprtk_loop( 7)
+               exprtk_loop( 8) exprtk_loop( 9)
+               exprtk_loop(10) exprtk_loop(11)
+               exprtk_loop(12) exprtk_loop(13)
+               exprtk_loop(14) exprtk_loop(15)
+               #endif
+
+               vec += lud.batch_size;
+            }
+
+            int i = 0;
+
+            exprtk_disable_fallthrough_begin
+            switch (lud.remainder)
+            {
+               #define case_stmt(N)       \
+               case N : r[0] *= vec[i++]; \
+
+               #ifndef exprtk_disable_superscalar_unroll
+               case_stmt(15) case_stmt(14)
+               case_stmt(13) case_stmt(12)
+               case_stmt(11) case_stmt(10)
+               case_stmt( 9) case_stmt( 8)
+               case_stmt( 7) case_stmt( 6)
+               case_stmt( 5) case_stmt( 4)
+               #endif
+               case_stmt( 3) case_stmt( 2)
+               case_stmt( 1)
+            }
+            exprtk_disable_fallthrough_end
+
+            #undef exprtk_loop
+            #undef case_stmt
+
+            return (r[ 0] * r[ 1] * r[ 2] * r[ 3])
+                   #ifndef exprtk_disable_superscalar_unroll
+                 + (r[ 4] * r[ 5] * r[ 6] * r[ 7])
+                 + (r[ 8] * r[ 9] * r[10] * r[11])
+                 + (r[12] * r[13] * r[14] * r[15])
+                   #endif
+                   ;
+         }
+      };
+
+      template <typename T>
+      struct vec_avg_op
+      {
+         typedef vector_interface<T>* ivector_ptr;
+
+         static inline T process(const ivector_ptr v)
+         {
+            const std::size_t vec_size = v->vec()->vds().size();
+
+            return vec_add_op<T>::process(v) / vec_size;
+         }
+      };
+
+      template <typename T>
+      struct vec_min_op
+      {
+         typedef vector_interface<T>* ivector_ptr;
+
+         static inline T process(const ivector_ptr v)
+         {
+            const T* vec = v->vec()->vds().data();
+            const std::size_t vec_size = v->vec()->vds().size();
+
+            T result = vec[0];
+
+            for (std::size_t i = 1; i < vec_size; ++i)
+            {
+               T v_i = vec[i];
+
+               if (v_i < result)
+                  result = v_i;
+            }
+
+            return result;
+         }
+      };
+
+      template <typename T>
+      struct vec_max_op
+      {
+         typedef vector_interface<T>* ivector_ptr;
+
+         static inline T process(const ivector_ptr v)
+         {
+            const T* vec = v->vec()->vds().data();
+            const std::size_t vec_size = v->vec()->vds().size();
+
+            T result = vec[0];
+
+            for (std::size_t i = 1; i < vec_size; ++i)
+            {
+               T v_i = vec[i];
+
+               if (v_i > result)
+                  result = v_i;
+            }
+
+            return result;
+         }
+      };
+
+      template <typename T>
+      class vov_base_node : public expression_node<T>
+      {
+      public:
+
+         virtual ~vov_base_node()
+         {}
+
+         inline virtual operator_type operation() const
+         {
+            return details::e_default;
+         }
+
+         virtual const T& v0() const = 0;
+
+         virtual const T& v1() const = 0;
+      };
+
+      template <typename T>
+      class cov_base_node : public expression_node<T>
+      {
+      public:
+
+       virtual ~cov_base_node()
+          {}
+
+         inline virtual operator_type operation() const
+         {
+            return details::e_default;
+         }
+
+         virtual const T c() const = 0;
+
+         virtual const T& v() const = 0;
+      };
+
+      template <typename T>
+      class voc_base_node : public expression_node<T>
+      {
+      public:
+
+         virtual ~voc_base_node()
+         {}
+
+         inline virtual operator_type operation() const
+         {
+            return details::e_default;
+         }
+
+         virtual const T c() const = 0;
+
+         virtual const T& v() const = 0;
+      };
+
+      template <typename T>
+      class vob_base_node : public expression_node<T>
+      {
+      public:
+
+         virtual ~vob_base_node()
+         {}
+
+         virtual const T& v() const = 0;
+      };
+
+      template <typename T>
+      class bov_base_node : public expression_node<T>
+      {
+      public:
+
+         virtual ~bov_base_node()
+         {}
+
+         virtual const T& v() const = 0;
+      };
+
+      template <typename T>
+      class cob_base_node : public expression_node<T>
+      {
+      public:
+
+       virtual ~cob_base_node()
+       {}
+
+         inline virtual operator_type operation() const
+         {
+            return details::e_default;
+         }
+
+         virtual const T c() const = 0;
+
+         virtual void set_c(const T) = 0;
+
+         virtual expression_node<T>* move_branch(const std::size_t& index) = 0;
+      };
+
+      template <typename T>
+      class boc_base_node : public expression_node<T>
+      {
+      public:
+
+         virtual ~boc_base_node()
+         {}
+
+         inline virtual operator_type operation() const
+         {
+            return details::e_default;
+         }
+
+         virtual const T c() const = 0;
+
+         virtual void set_c(const T) = 0;
+
+         virtual expression_node<T>* move_branch(const std::size_t& index) = 0;
+      };
+
+      template <typename T>
+      class uv_base_node : public expression_node<T>
+      {
+      public:
+
+         virtual ~uv_base_node()
+         {}
+
+         inline virtual operator_type operation() const
+         {
+            return details::e_default;
+         }
+
+         virtual const T& v() const = 0;
+      };
+
+      template <typename T>
+      class sos_base_node : public expression_node<T>
+      {
+      public:
+
+         virtual ~sos_base_node()
+         {}
+
+         inline virtual operator_type operation() const
+         {
+            return details::e_default;
+         }
+      };
+
+      template <typename T>
+      class sosos_base_node : public expression_node<T>
+      {
+      public:
+
+         virtual ~sosos_base_node()
+         {}
+
+         inline virtual operator_type operation() const
+         {
+            return details::e_default;
+         }
+      };
+
+      template <typename T>
+      class T0oT1oT2_base_node : public expression_node<T>
+      {
+      public:
+
+         virtual ~T0oT1oT2_base_node()
+         {}
+
+         virtual std::string type_id() const = 0;
+      };
+
+      template <typename T>
+      class T0oT1oT2oT3_base_node : public expression_node<T>
+      {
+      public:
+
+         virtual ~T0oT1oT2oT3_base_node()
+         {}
+
+         virtual std::string type_id() const = 0;
+      };
+
+      template <typename T, typename Operation>
+      class unary_variable_node : public uv_base_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+         typedef Operation operation_t;
+
+         explicit unary_variable_node(const T& var)
+         : v_(var)
+         {}
+
+         inline T value() const
+         {
+            return Operation::process(v_);
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return Operation::type();
+         }
+
+         inline operator_type operation() const
+         {
+            return Operation::operation();
+         }
+
+         inline const T& v() const
+         {
+            return v_;
+         }
+
+      private:
+
+         unary_variable_node(unary_variable_node<T,Operation>&);
+         unary_variable_node<T,Operation>& operator=(unary_variable_node<T,Operation>&);
+
+         const T& v_;
+      };
+
+      template <typename T>
+      class uvouv_node : public expression_node<T>
+      {
+      public:
+
+         // UOpr1(v0) Op UOpr2(v1)
+
+         typedef expression_node<T>* expression_ptr;
+         typedef typename details::functor_t<T> functor_t;
+         typedef typename functor_t::bfunc_t      bfunc_t;
+         typedef typename functor_t::ufunc_t      ufunc_t;
+
+         explicit uvouv_node(const T& var0,const T& var1,
+                             ufunc_t uf0, ufunc_t uf1, bfunc_t bf)
+         : v0_(var0),
+           v1_(var1),
+           u0_(uf0 ),
+           u1_(uf1 ),
+           f_ (bf  )
+         {}
+
+         inline T value() const
+         {
+            return f_(u0_(v0_),u1_(v1_));
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_uvouv;
+         }
+
+         inline operator_type operation() const
+         {
+            return details::e_default;
+         }
+
+         inline const T& v0()
+         {
+            return v0_;
+         }
+
+         inline const T& v1()
+         {
+            return v1_;
+         }
+
+         inline ufunc_t u0()
+         {
+            return u0_;
+         }
+
+         inline ufunc_t u1()
+         {
+            return u1_;
+         }
+
+         inline ufunc_t f()
+         {
+            return f_;
+         }
+
+      private:
+
+         uvouv_node(uvouv_node<T>&);
+         uvouv_node<T>& operator=(uvouv_node<T>&);
+
+         const T& v0_;
+         const T& v1_;
+         const ufunc_t u0_;
+         const ufunc_t u1_;
+         const bfunc_t f_;
+      };
+
+      template <typename T, typename Operation>
+      class unary_branch_node : public expression_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+         typedef Operation operation_t;
+
+         explicit unary_branch_node(expression_ptr brnch)
+         : branch_(brnch),
+           branch_deletable_(branch_deletable(branch_))
+         {}
+
+        ~unary_branch_node()
+         {
+            if (branch_ && branch_deletable_)
+            {
+               destroy_node(branch_);
+            }
+         }
+
+         inline T value() const
+         {
+            return Operation::process(branch_->value());
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return Operation::type();
+         }
+
+         inline operator_type operation() const
+         {
+            return Operation::operation();
+         }
+
+         inline expression_node<T>* branch(const std::size_t&) const
+         {
+            return branch_;
+         }
+
+         inline void release()
+         {
+            branch_deletable_ = false;
+         }
+
+      private:
+
+         unary_branch_node(unary_branch_node<T,Operation>&);
+         unary_branch_node<T,Operation>& operator=(unary_branch_node<T,Operation>&);
+
+         expression_ptr branch_;
+         bool           branch_deletable_;
+      };
+
+      template <typename T> struct is_const                { enum {result = 0}; };
+      template <typename T> struct is_const <const T>      { enum {result = 1}; };
+      template <typename T> struct is_const_ref            { enum {result = 0}; };
+      template <typename T> struct is_const_ref <const T&> { enum {result = 1}; };
+      template <typename T> struct is_ref                  { enum {result = 0}; };
+      template <typename T> struct is_ref<T&>              { enum {result = 1}; };
+      template <typename T> struct is_ref<const T&>        { enum {result = 0}; };
+
+      template <std::size_t State>
+      struct param_to_str { static std::string result() { static const std::string r("v"); return r; } };
+
+      template <>
+      struct param_to_str<0> { static std::string result() { static const std::string r("c"); return r; } };
+
+      #define exprtk_crtype(Type)                          \
+      param_to_str<is_const_ref< Type >::result>::result() \
+
+      template <typename T>
+      struct T0oT1oT2process
+      {
+         typedef typename details::functor_t<T> functor_t;
+         typedef typename functor_t::bfunc_t      bfunc_t;
+
+         struct mode0
+         {
+            static inline T process(const T& t0, const T& t1, const T& t2, const bfunc_t bf0, const bfunc_t bf1)
+            {
+               // (T0 o0 T1) o1 T2
+               return bf1(bf0(t0,t1),t2);
+            }
+
+            template <typename T0, typename T1, typename T2>
+            static inline std::string id()
+            {
+               static const std::string result = "(" + exprtk_crtype(T0) + "o"   +
+                                                       exprtk_crtype(T1) + ")o(" +
+                                                       exprtk_crtype(T2) + ")"   ;
+               return result;
+            }
+         };
+
+         struct mode1
+         {
+            static inline T process(const T& t0, const T& t1, const T& t2, const bfunc_t bf0, const bfunc_t bf1)
+            {
+               // T0 o0 (T1 o1 T2)
+               return bf0(t0,bf1(t1,t2));
+            }
+
+            template <typename T0, typename T1, typename T2>
+            static inline std::string id()
+            {
+               static const std::string result = "(" + exprtk_crtype(T0) + ")o(" +
+                                                       exprtk_crtype(T1) + "o"   +
+                                                       exprtk_crtype(T2) + ")"   ;
+               return result;
+            }
+         };
+      };
+
+      template <typename T>
+      struct T0oT1oT20T3process
+      {
+         typedef typename details::functor_t<T> functor_t;
+         typedef typename functor_t::bfunc_t      bfunc_t;
+
+         struct mode0
+         {
+            static inline T process(const T& t0, const T& t1,
+                                    const T& t2, const T& t3,
+                                    const bfunc_t bf0, const bfunc_t bf1, const bfunc_t bf2)
+            {
+               // (T0 o0 T1) o1 (T2 o2 T3)
+               return bf1(bf0(t0,t1),bf2(t2,t3));
+            }
+
+            template <typename T0, typename T1, typename T2, typename T3>
+            static inline std::string id()
+            {
+               static const std::string result = "(" + exprtk_crtype(T0) + "o"  +
+                                                       exprtk_crtype(T1) + ")o" +
+                                                 "(" + exprtk_crtype(T2) + "o"  +
+                                                       exprtk_crtype(T3) + ")"  ;
+               return result;
+            }
+         };
+
+         struct mode1
+         {
+            static inline T process(const T& t0, const T& t1,
+                                    const T& t2, const T& t3,
+                                    const bfunc_t bf0, const bfunc_t bf1, const bfunc_t bf2)
+            {
+               // (T0 o0 (T1 o1 (T2 o2 T3))
+               return bf0(t0,bf1(t1,bf2(t2,t3)));
+            }
+            template <typename T0, typename T1, typename T2, typename T3>
+            static inline std::string id()
+            {
+               static const std::string result = "(" + exprtk_crtype(T0) +  ")o((" +
+                                                       exprtk_crtype(T1) +  ")o("  +
+                                                       exprtk_crtype(T2) +  "o"    +
+                                                       exprtk_crtype(T3) +  "))"   ;
+               return result;
+            }
+         };
+
+         struct mode2
+         {
+            static inline T process(const T& t0, const T& t1,
+                                    const T& t2, const T& t3,
+                                    const bfunc_t bf0, const bfunc_t bf1, const bfunc_t bf2)
+            {
+               // (T0 o0 ((T1 o1 T2) o2 T3)
+               return bf0(t0,bf2(bf1(t1,t2),t3));
+            }
+
+            template <typename T0, typename T1, typename T2, typename T3>
+            static inline std::string id()
+            {
+               static const std::string result = "(" + exprtk_crtype(T0) + ")o((" +
+                                                       exprtk_crtype(T1) + "o"    +
+                                                       exprtk_crtype(T2) + ")o("  +
+                                                       exprtk_crtype(T3) + "))"   ;
+               return result;
+            }
+         };
+
+         struct mode3
+         {
+            static inline T process(const T& t0, const T& t1,
+                                    const T& t2, const T& t3,
+                                    const bfunc_t bf0, const bfunc_t bf1, const bfunc_t bf2)
+            {
+               // (((T0 o0 T1) o1 T2) o2 T3)
+               return bf2(bf1(bf0(t0,t1),t2),t3);
+            }
+
+            template <typename T0, typename T1, typename T2, typename T3>
+            static inline std::string id()
+            {
+               static const std::string result = "((" + exprtk_crtype(T0) + "o"    +
+                                                        exprtk_crtype(T1) + ")o("  +
+                                                        exprtk_crtype(T2) + "))o(" +
+                                                        exprtk_crtype(T3) + ")";
+               return result;
+            }
+         };
+
+         struct mode4
+         {
+            static inline T process(const T& t0, const T& t1,
+                                    const T& t2, const T& t3,
+                                    const bfunc_t bf0, const bfunc_t bf1, const bfunc_t bf2)
+            {
+               // ((T0 o0 (T1 o1 T2)) o2 T3
+               return bf2(bf0(t0,bf1(t1,t2)),t3);
+            }
+
+            template <typename T0, typename T1, typename T2, typename T3>
+            static inline std::string id()
+            {
+               static const std::string result = "((" + exprtk_crtype(T0) + ")o("  +
+                                                        exprtk_crtype(T1) + "o"    +
+                                                        exprtk_crtype(T2) + "))o(" +
+                                                        exprtk_crtype(T3) + ")"    ;
+               return result;
+            }
+         };
+      };
+
+      #undef exprtk_crtype
+
+      template <typename T, typename T0, typename T1>
+      struct nodetype_T0oT1 { static const typename expression_node<T>::node_type result; };
+      template <typename T, typename T0, typename T1>
+      const typename expression_node<T>::node_type nodetype_T0oT1<T,T0,T1>::result = expression_node<T>::e_none;
+
+      #define synthesis_node_type_define(T0_,T1_,v_)                                                            \
+      template <typename T, typename T0, typename T1>                                                           \
+      struct nodetype_T0oT1<T,T0_,T1_> { static const typename expression_node<T>::node_type result; };         \
+      template <typename T, typename T0, typename T1>                                                           \
+      const typename expression_node<T>::node_type nodetype_T0oT1<T,T0_,T1_>::result = expression_node<T>:: v_; \
+
+      synthesis_node_type_define(const T0&, const T1&,  e_vov)
+      synthesis_node_type_define(const T0&, const T1 ,  e_voc)
+      synthesis_node_type_define(const T0 , const T1&,  e_cov)
+      synthesis_node_type_define(      T0&,       T1&, e_none)
+      synthesis_node_type_define(const T0 , const T1 , e_none)
+      synthesis_node_type_define(      T0&, const T1 , e_none)
+      synthesis_node_type_define(const T0 ,       T1&, e_none)
+      synthesis_node_type_define(const T0&,       T1&, e_none)
+      synthesis_node_type_define(      T0&, const T1&, e_none)
+      #undef synthesis_node_type_define
+
+      template <typename T, typename T0, typename T1, typename T2>
+      struct nodetype_T0oT1oT2 { static const typename expression_node<T>::node_type result; };
+      template <typename T, typename T0, typename T1, typename T2>
+      const typename expression_node<T>::node_type nodetype_T0oT1oT2<T,T0,T1,T2>::result = expression_node<T>::e_none;
+
+      #define synthesis_node_type_define(T0_,T1_,T2_,v_)                                                               \
+      template <typename T, typename T0, typename T1, typename T2>                                                     \
+      struct nodetype_T0oT1oT2<T,T0_,T1_,T2_> { static const typename expression_node<T>::node_type result; };         \
+      template <typename T, typename T0, typename T1, typename T2>                                                     \
+      const typename expression_node<T>::node_type nodetype_T0oT1oT2<T,T0_,T1_,T2_>::result = expression_node<T>:: v_; \
+
+      synthesis_node_type_define(const T0&, const T1&, const T2&, e_vovov)
+      synthesis_node_type_define(const T0&, const T1&, const T2 , e_vovoc)
+      synthesis_node_type_define(const T0&, const T1 , const T2&, e_vocov)
+      synthesis_node_type_define(const T0 , const T1&, const T2&, e_covov)
+      synthesis_node_type_define(const T0 , const T1&, const T2 , e_covoc)
+      synthesis_node_type_define(const T0 , const T1 , const T2 , e_none )
+      synthesis_node_type_define(const T0 , const T1 , const T2&, e_none )
+      synthesis_node_type_define(const T0&, const T1 , const T2 , e_none )
+      synthesis_node_type_define(      T0&,       T1&,       T2&, e_none )
+      #undef synthesis_node_type_define
+
+      template <typename T, typename T0, typename T1, typename T2, typename T3>
+      struct nodetype_T0oT1oT2oT3 { static const typename expression_node<T>::node_type result; };
+      template <typename T, typename T0, typename T1, typename T2, typename T3>
+      const typename expression_node<T>::node_type nodetype_T0oT1oT2oT3<T,T0,T1,T2,T3>::result = expression_node<T>::e_none;
+
+      #define synthesis_node_type_define(T0_,T1_,T2_,T3_,v_)                                                                  \
+      template <typename T, typename T0, typename T1, typename T2, typename T3>                                               \
+      struct nodetype_T0oT1oT2oT3<T,T0_,T1_,T2_,T3_> { static const typename expression_node<T>::node_type result; };         \
+      template <typename T, typename T0, typename T1, typename T2, typename T3>                                               \
+      const typename expression_node<T>::node_type nodetype_T0oT1oT2oT3<T,T0_,T1_,T2_,T3_>::result = expression_node<T>:: v_; \
+
+      synthesis_node_type_define(const T0&, const T1&, const T2&, const T3&, e_vovovov)
+      synthesis_node_type_define(const T0&, const T1&, const T2&, const T3 , e_vovovoc)
+      synthesis_node_type_define(const T0&, const T1&, const T2 , const T3&, e_vovocov)
+      synthesis_node_type_define(const T0&, const T1 , const T2&, const T3&, e_vocovov)
+      synthesis_node_type_define(const T0 , const T1&, const T2&, const T3&, e_covovov)
+      synthesis_node_type_define(const T0 , const T1&, const T2 , const T3&, e_covocov)
+      synthesis_node_type_define(const T0&, const T1 , const T2&, const T3 , e_vocovoc)
+      synthesis_node_type_define(const T0 , const T1&, const T2&, const T3 , e_covovoc)
+      synthesis_node_type_define(const T0&, const T1 , const T2 , const T3&, e_vococov)
+      synthesis_node_type_define(const T0 , const T1 , const T2 , const T3 , e_none   )
+      synthesis_node_type_define(const T0 , const T1 , const T2 , const T3&, e_none   )
+      synthesis_node_type_define(const T0 , const T1 , const T2&, const T3 , e_none   )
+      synthesis_node_type_define(const T0 , const T1&, const T2 , const T3 , e_none   )
+      synthesis_node_type_define(const T0&, const T1 , const T2 , const T3 , e_none   )
+      synthesis_node_type_define(const T0 , const T1 , const T2&, const T3&, e_none   )
+      synthesis_node_type_define(const T0&, const T1&, const T2 , const T3 , e_none   )
+      #undef synthesis_node_type_define
+
+      template <typename T, typename T0, typename T1>
+      class T0oT1 : public expression_node<T>
+      {
+      public:
+
+         typedef typename details::functor_t<T> functor_t;
+         typedef typename functor_t::bfunc_t      bfunc_t;
+         typedef T value_type;
+         typedef T0oT1<T,T0,T1> node_type;
+
+         T0oT1(T0 p0, T1 p1, const bfunc_t p2)
+         : t0_(p0),
+           t1_(p1),
+           f_ (p2)
+         {}
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            static const typename expression_node<T>::node_type result = nodetype_T0oT1<T,T0,T1>::result;
+            return result;
+         }
+
+         inline operator_type operation() const
+         {
+            return e_default;
+         }
+
+         inline T value() const
+         {
+            return f_(t0_,t1_);
+         }
+
+         inline T0 t0() const
+         {
+            return t0_;
+         }
+
+         inline T1 t1() const
+         {
+            return t1_;
+         }
+
+         inline bfunc_t f() const
+         {
+            return f_;
+         }
+
+         template <typename Allocator>
+         static inline expression_node<T>* allocate(Allocator& allocator,
+                                                    T0 p0, T1 p1,
+                                                    bfunc_t p2)
+         {
+            return allocator
+                     .template allocate_type<node_type, T0, T1, bfunc_t&>
+                        (p0, p1, p2);
+         }
+
+      private:
+
+         T0oT1(T0oT1<T,T0,T1>&) {}
+         T0oT1<T,T0,T1>& operator=(T0oT1<T,T0,T1>&) { return (*this); }
+
+         T0 t0_;
+         T1 t1_;
+         const bfunc_t f_;
+      };
+
+      template <typename T, typename T0, typename T1, typename T2, typename ProcessMode>
+      class T0oT1oT2 : public T0oT1oT2_base_node<T>
+      {
+      public:
+
+         typedef typename details::functor_t<T> functor_t;
+         typedef typename functor_t::bfunc_t      bfunc_t;
+         typedef T value_type;
+         typedef T0oT1oT2<T,T0,T1,T2,ProcessMode> node_type;
+         typedef ProcessMode process_mode_t;
+
+         T0oT1oT2(T0 p0, T1 p1, T2 p2, const bfunc_t p3, const bfunc_t p4)
+         : t0_(p0),
+           t1_(p1),
+           t2_(p2),
+           f0_(p3),
+           f1_(p4)
+         {}
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            static const typename expression_node<T>::node_type result = nodetype_T0oT1oT2<T,T0,T1,T2>::result;
+            return result;
+         }
+
+         inline operator_type operation() const
+         {
+            return e_default;
+         }
+
+         inline T value() const
+         {
+            return ProcessMode::process(t0_, t1_, t2_, f0_, f1_);
+         }
+
+         inline T0 t0() const
+         {
+            return t0_;
+         }
+
+         inline T1 t1() const
+         {
+            return t1_;
+         }
+
+         inline T2 t2() const
+         {
+            return t2_;
+         }
+
+         bfunc_t f0() const
+         {
+            return f0_;
+         }
+
+         bfunc_t f1() const
+         {
+            return f1_;
+         }
+
+         std::string type_id() const
+         {
+            return id();
+         }
+
+         static inline std::string id()
+         {
+            return process_mode_t::template id<T0,T1,T2>();
+         }
+
+         template <typename Allocator>
+         static inline expression_node<T>* allocate(Allocator& allocator, T0 p0, T1 p1, T2 p2, bfunc_t p3, bfunc_t p4)
+         {
+            return allocator
+                      .template allocate_type<node_type, T0, T1, T2, bfunc_t, bfunc_t>
+                         (p0, p1, p2, p3, p4);
+         }
+
+      private:
+
+         T0oT1oT2(node_type&) {}
+         node_type& operator=(node_type&) { return (*this); }
+
+         T0 t0_;
+         T1 t1_;
+         T2 t2_;
+         const bfunc_t f0_;
+         const bfunc_t f1_;
+      };
+
+      template <typename T, typename T0_, typename T1_, typename T2_, typename T3_, typename ProcessMode>
+      class T0oT1oT2oT3 : public T0oT1oT2oT3_base_node<T>
+      {
+      public:
+
+         typedef typename details::functor_t<T> functor_t;
+         typedef typename functor_t::bfunc_t      bfunc_t;
+         typedef T value_type;
+         typedef T0_ T0;
+         typedef T1_ T1;
+         typedef T2_ T2;
+         typedef T3_ T3;
+         typedef T0oT1oT2oT3<T,T0,T1,T2,T3,ProcessMode> node_type;
+         typedef ProcessMode process_mode_t;
+
+         T0oT1oT2oT3(T0 p0, T1 p1, T2 p2, T3 p3, bfunc_t p4, bfunc_t p5, bfunc_t p6)
+         : t0_(p0),
+           t1_(p1),
+           t2_(p2),
+           t3_(p3),
+           f0_(p4),
+           f1_(p5),
+           f2_(p6)
+         {}
+
+         inline T value() const
+         {
+            return ProcessMode::process(t0_, t1_, t2_, t3_, f0_, f1_, f2_);
+         }
+
+         inline T0 t0() const
+         {
+            return t0_;
+         }
+
+         inline T1 t1() const
+         {
+            return t1_;
+         }
+
+         inline T2 t2() const
+         {
+            return t2_;
+         }
+
+         inline T3 t3() const
+         {
+            return t3_;
+         }
+
+         inline bfunc_t f0() const
+         {
+            return f0_;
+         }
+
+         inline bfunc_t f1() const
+         {
+            return f1_;
+         }
+
+         inline bfunc_t f2() const
+         {
+            return f2_;
+         }
+
+         inline std::string type_id() const
+         {
+            return id();
+         }
+
+         static inline std::string id()
+         {
+            return process_mode_t::template id<T0, T1, T2, T3>();
+         }
+
+         template <typename Allocator>
+         static inline expression_node<T>* allocate(Allocator& allocator,
+                                                    T0 p0, T1 p1, T2 p2, T3 p3,
+                                                    bfunc_t p4, bfunc_t p5, bfunc_t p6)
+         {
+            return allocator
+                      .template allocate_type<node_type, T0, T1, T2, T3, bfunc_t, bfunc_t>
+                         (p0, p1, p2, p3, p4, p5, p6);
+         }
+
+      private:
+
+         T0oT1oT2oT3(node_type&) {}
+         node_type& operator=(node_type&) { return (*this); }
+
+         T0 t0_;
+         T1 t1_;
+         T2 t2_;
+         T3 t3_;
+         const bfunc_t f0_;
+         const bfunc_t f1_;
+         const bfunc_t f2_;
+      };
+
+      template <typename T, typename T0, typename T1, typename T2>
+      class T0oT1oT2_sf3 : public T0oT1oT2_base_node<T>
+      {
+      public:
+
+         typedef typename details::functor_t<T> functor_t;
+         typedef typename functor_t::tfunc_t      tfunc_t;
+         typedef T value_type;
+         typedef T0oT1oT2_sf3<T,T0,T1,T2> node_type;
+
+         T0oT1oT2_sf3(T0 p0, T1 p1, T2 p2, const tfunc_t p3)
+         : t0_(p0),
+           t1_(p1),
+           t2_(p2),
+           f_ (p3)
+         {}
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            static const typename expression_node<T>::node_type result = nodetype_T0oT1oT2<T,T0,T1,T2>::result;
+            return result;
+         }
+
+         inline operator_type operation() const
+         {
+            return e_default;
+         }
+
+         inline T value() const
+         {
+            return f_(t0_, t1_, t2_);
+         }
+
+         inline T0 t0() const
+         {
+            return t0_;
+         }
+
+         inline T1 t1() const
+         {
+            return t1_;
+         }
+
+         inline T2 t2() const
+         {
+            return t2_;
+         }
+
+         tfunc_t f() const
+         {
+            return f_;
+         }
+
+         std::string type_id() const
+         {
+            return id();
+         }
+
+         static inline std::string id()
+         {
+            return "sf3";
+         }
+
+         template <typename Allocator>
+         static inline expression_node<T>* allocate(Allocator& allocator, T0 p0, T1 p1, T2 p2, tfunc_t p3)
+         {
+            return allocator
+                     .template allocate_type<node_type, T0, T1, T2, tfunc_t>
+                        (p0, p1, p2, p3);
+         }
+
+      private:
+
+         T0oT1oT2_sf3(node_type&) {}
+         node_type& operator=(node_type&) { return (*this); }
+
+         T0 t0_;
+         T1 t1_;
+         T2 t2_;
+         const tfunc_t f_;
+      };
+
+      template <typename T, typename T0, typename T1, typename T2>
+      class sf3ext_type_node : public T0oT1oT2_base_node<T>
+      {
+      public:
+
+         virtual ~sf3ext_type_node()
+         {}
+
+         virtual T0 t0() const = 0;
+
+         virtual T1 t1() const = 0;
+
+         virtual T2 t2() const = 0;
+      };
+
+      template <typename T, typename T0, typename T1, typename T2, typename SF3Operation>
+      class T0oT1oT2_sf3ext : public sf3ext_type_node<T,T0,T1,T2>
+      {
+      public:
+
+         typedef typename details::functor_t<T> functor_t;
+         typedef typename functor_t::tfunc_t      tfunc_t;
+         typedef T value_type;
+         typedef T0oT1oT2_sf3ext<T,T0,T1,T2,SF3Operation> node_type;
+
+         T0oT1oT2_sf3ext(T0 p0, T1 p1, T2 p2)
+         : t0_(p0),
+           t1_(p1),
+           t2_(p2)
+         {}
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            static const typename expression_node<T>::node_type result = nodetype_T0oT1oT2<T,T0,T1,T2>::result;
+            return result;
+         }
+
+         inline operator_type operation() const
+         {
+            return e_default;
+         }
+
+         inline T value() const
+         {
+            return SF3Operation::process(t0_, t1_, t2_);
+         }
+
+         T0 t0() const
+         {
+            return t0_;
+         }
+
+         T1 t1() const
+         {
+            return t1_;
+         }
+
+         T2 t2() const
+         {
+            return t2_;
+         }
+
+         std::string type_id() const
+         {
+            return id();
+         }
+
+         static inline std::string id()
+         {
+            return SF3Operation::id();
+         }
+
+         template <typename Allocator>
+         static inline expression_node<T>* allocate(Allocator& allocator, T0 p0, T1 p1, T2 p2)
+         {
+            return allocator
+                     .template allocate_type<node_type, T0, T1, T2>
+                        (p0, p1, p2);
+         }
+
+      private:
+
+         T0oT1oT2_sf3ext(node_type&) {}
+         node_type& operator=(node_type&) { return (*this); }
+
+         T0 t0_;
+         T1 t1_;
+         T2 t2_;
+      };
+
+      template <typename T>
+      inline bool is_sf3ext_node(const expression_node<T>* n)
+      {
+         switch (n->type())
+         {
+            case expression_node<T>::e_vovov : return true;
+            case expression_node<T>::e_vovoc : return true;
+            case expression_node<T>::e_vocov : return true;
+            case expression_node<T>::e_covov : return true;
+            case expression_node<T>::e_covoc : return true;
+            default                          : return false;
+         }
+      }
+
+      template <typename T, typename T0, typename T1, typename T2, typename T3>
+      class T0oT1oT2oT3_sf4 : public T0oT1oT2_base_node<T>
+      {
+      public:
+
+         typedef typename details::functor_t<T> functor_t;
+         typedef typename functor_t::qfunc_t      qfunc_t;
+         typedef T value_type;
+         typedef T0oT1oT2oT3_sf4<T,T0,T1,T2,T3> node_type;
+
+         T0oT1oT2oT3_sf4(T0 p0, T1 p1, T2 p2, T3 p3, const qfunc_t p4)
+         : t0_(p0),
+           t1_(p1),
+           t2_(p2),
+           t3_(p3),
+           f_ (p4)
+         {}
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            static const typename expression_node<T>::node_type result = nodetype_T0oT1oT2oT3<T,T0,T1,T2,T3>::result;
+            return result;
+         }
+
+         inline operator_type operation() const
+         {
+            return e_default;
+         }
+
+         inline T value() const
+         {
+            return f_(t0_, t1_, t2_, t3_);
+         }
+
+         inline T0 t0() const
+         {
+            return t0_;
+         }
+
+         inline T1 t1() const
+         {
+            return t1_;
+         }
+
+         inline T2 t2() const
+         {
+            return t2_;
+         }
+
+         inline T3 t3() const
+         {
+            return t3_;
+         }
+
+         qfunc_t f() const
+         {
+            return f_;
+         }
+
+         std::string type_id() const
+         {
+            return id();
+         }
+
+         static inline std::string id()
+         {
+            return "sf4";
+         }
+
+         template <typename Allocator>
+         static inline expression_node<T>* allocate(Allocator& allocator, T0 p0, T1 p1, T2 p2, T3 p3, qfunc_t p4)
+         {
+            return allocator
+                     .template allocate_type<node_type, T0, T1, T2, T3, qfunc_t>
+                        (p0, p1, p2, p3, p4);
+         }
+
+      private:
+
+         T0oT1oT2oT3_sf4(node_type&) {}
+         node_type& operator=(node_type&) { return (*this); }
+
+         T0 t0_;
+         T1 t1_;
+         T2 t2_;
+         T3 t3_;
+         const qfunc_t f_;
+      };
+
+      template <typename T, typename T0, typename T1, typename T2, typename T3, typename SF4Operation>
+      class T0oT1oT2oT3_sf4ext : public T0oT1oT2oT3_base_node<T>
+      {
+      public:
+
+         typedef typename details::functor_t<T> functor_t;
+         typedef typename functor_t::tfunc_t      tfunc_t;
+         typedef T value_type;
+         typedef T0oT1oT2oT3_sf4ext<T,T0,T1,T2,T3,SF4Operation> node_type;
+
+         T0oT1oT2oT3_sf4ext(T0 p0, T1 p1, T2 p2, T3 p3)
+         : t0_(p0),
+           t1_(p1),
+           t2_(p2),
+           t3_(p3)
+         {}
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            static const typename expression_node<T>::node_type result = nodetype_T0oT1oT2oT3<T,T0,T1,T2,T3>::result;
+            return result;
+         }
+
+         inline operator_type operation() const
+         {
+            return e_default;
+         }
+
+         inline T value() const
+         {
+            return SF4Operation::process(t0_, t1_, t2_, t3_);
+         }
+
+         inline T0 t0() const
+         {
+            return t0_;
+         }
+
+         inline T1 t1() const
+         {
+            return t1_;
+         }
+
+         inline T2 t2() const
+         {
+            return t2_;
+         }
+
+         inline T3 t3() const
+         {
+            return t3_;
+         }
+
+         std::string type_id() const
+         {
+            return id();
+         }
+
+         static inline std::string id()
+         {
+            return SF4Operation::id();
+         }
+
+         template <typename Allocator>
+         static inline expression_node<T>* allocate(Allocator& allocator, T0 p0, T1 p1, T2 p2, T3 p3)
+         {
+            return allocator
+                     .template allocate_type<node_type, T0, T1, T2, T3>
+                        (p0, p1, p2, p3);
+         }
+
+      private:
+
+         T0oT1oT2oT3_sf4ext(node_type&) {}
+         node_type& operator=(node_type&) { return (*this); }
+
+         T0 t0_;
+         T1 t1_;
+         T2 t2_;
+         T3 t3_;
+      };
+
+      template <typename T>
+      inline bool is_sf4ext_node(const expression_node<T>* n)
+      {
+         switch (n->type())
+         {
+            case expression_node<T>::e_vovovov : return true;
+            case expression_node<T>::e_vovovoc : return true;
+            case expression_node<T>::e_vovocov : return true;
+            case expression_node<T>::e_vocovov : return true;
+            case expression_node<T>::e_covovov : return true;
+            case expression_node<T>::e_covocov : return true;
+            case expression_node<T>::e_vocovoc : return true;
+            case expression_node<T>::e_covovoc : return true;
+            case expression_node<T>::e_vococov : return true;
+            default                            : return false;
+         }
+      }
+
+      template <typename T, typename T0, typename T1>
+      struct T0oT1_define
+      {
+         typedef details::T0oT1<T, T0, T1> type0;
+      };
+
+      template <typename T, typename T0, typename T1, typename T2>
+      struct T0oT1oT2_define
+      {
+         typedef details::T0oT1oT2<T, T0, T1, T2, typename T0oT1oT2process<T>::mode0> type0;
+         typedef details::T0oT1oT2<T, T0, T1, T2, typename T0oT1oT2process<T>::mode1> type1;
+         typedef details::T0oT1oT2_sf3<T, T0, T1, T2> sf3_type;
+         typedef details::sf3ext_type_node<T, T0, T1, T2> sf3_type_node;
+      };
+
+      template <typename T, typename T0, typename T1, typename T2, typename T3>
+      struct T0oT1oT2oT3_define
+      {
+         typedef details::T0oT1oT2oT3<T, T0, T1, T2, T3, typename T0oT1oT20T3process<T>::mode0> type0;
+         typedef details::T0oT1oT2oT3<T, T0, T1, T2, T3, typename T0oT1oT20T3process<T>::mode1> type1;
+         typedef details::T0oT1oT2oT3<T, T0, T1, T2, T3, typename T0oT1oT20T3process<T>::mode2> type2;
+         typedef details::T0oT1oT2oT3<T, T0, T1, T2, T3, typename T0oT1oT20T3process<T>::mode3> type3;
+         typedef details::T0oT1oT2oT3<T, T0, T1, T2, T3, typename T0oT1oT20T3process<T>::mode4> type4;
+         typedef details::T0oT1oT2oT3_sf4<T, T0, T1, T2, T3> sf4_type;
+      };
+
+      template <typename T, typename Operation>
+      class vov_node : public vov_base_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+         typedef Operation operation_t;
+
+         // variable op variable node
+         explicit vov_node(const T& var0, const T& var1)
+         : v0_(var0),
+           v1_(var1)
+         {}
+
+         inline T value() const
+         {
+            return Operation::process(v0_,v1_);
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return Operation::type();
+         }
+
+         inline operator_type operation() const
+         {
+            return Operation::operation();
+         }
+
+         inline const T& v0() const
+         {
+            return v0_;
+         }
+
+         inline const T& v1() const
+         {
+            return v1_;
+         }
+
+      protected:
+
+         const T& v0_;
+         const T& v1_;
+
+      private:
+
+         vov_node(vov_node<T,Operation>&);
+         vov_node<T,Operation>& operator=(vov_node<T,Operation>&);
+      };
+
+      template <typename T, typename Operation>
+      class cov_node : public cov_base_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+         typedef Operation operation_t;
+
+         // constant op variable node
+         explicit cov_node(const T& const_var, const T& var)
+         : c_(const_var),
+           v_(var)
+         {}
+
+         inline T value() const
+         {
+            return Operation::process(c_,v_);
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return Operation::type();
+         }
+
+         inline operator_type operation() const
+         {
+            return Operation::operation();
+         }
+
+         inline const T c() const
+         {
+            return c_;
+         }
+
+         inline const T& v() const
+         {
+            return v_;
+         }
+
+      protected:
+
+         const T  c_;
+         const T& v_;
+
+      private:
+
+         cov_node(const cov_node<T,Operation>&);
+         cov_node<T,Operation>& operator=(const cov_node<T,Operation>&);
+      };
+
+      template <typename T, typename Operation>
+      class voc_node : public voc_base_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+         typedef Operation operation_t;
+
+         // variable op constant node
+         explicit voc_node(const T& var, const T& const_var)
+         : v_(var),
+           c_(const_var)
+         {}
+
+         inline T value() const
+         {
+            return Operation::process(v_,c_);
+         }
+
+         inline operator_type operation() const
+         {
+            return Operation::operation();
+         }
+
+         inline const T c() const
+         {
+            return c_;
+         }
+
+         inline const T& v() const
+         {
+            return v_;
+         }
+
+      protected:
+
+         const T& v_;
+         const T  c_;
+
+      private:
+
+         voc_node(const voc_node<T,Operation>&);
+         voc_node<T,Operation>& operator=(const voc_node<T,Operation>&);
+      };
+
+      template <typename T, typename Operation>
+      class vob_node : public vob_base_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+         typedef std::pair<expression_ptr,bool> branch_t;
+         typedef Operation operation_t;
+
+         // variable op constant node
+         explicit vob_node(const T& var, const expression_ptr brnch)
+         : v_(var)
+         {
+            init_branches<1>(branch_,brnch);
+         }
+
+        ~vob_node()
+         {
+            cleanup_branches::execute<T,1>(branch_);
+         }
+
+         inline T value() const
+         {
+            return Operation::process(v_,branch_[0].first->value());
+         }
+
+         inline operator_type operation() const
+         {
+            return Operation::operation();
+         }
+
+         inline const T& v() const
+         {
+            return v_;
+         }
+
+         inline expression_node<T>* branch(const std::size_t&) const
+         {
+            return branch_[0].first;
+         }
+
+      private:
+
+         vob_node(const vob_node<T,Operation>&);
+         vob_node<T,Operation>& operator=(const vob_node<T,Operation>&);
+
+         const T& v_;
+         branch_t branch_[1];
+      };
+
+      template <typename T, typename Operation>
+      class bov_node : public bov_base_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+         typedef std::pair<expression_ptr,bool> branch_t;
+         typedef Operation operation_t;
+
+         // variable op constant node
+         explicit bov_node(const expression_ptr brnch, const T& var)
+         : v_(var)
+         {
+            init_branches<1>(branch_,brnch);
+         }
+
+        ~bov_node()
+         {
+            cleanup_branches::execute<T,1>(branch_);
+         }
+
+         inline T value() const
+         {
+            return Operation::process(branch_[0].first->value(),v_);
+         }
+
+         inline operator_type operation() const
+         {
+            return Operation::operation();
+         }
+
+         inline const T& v() const
+         {
+            return v_;
+         }
+
+         inline expression_node<T>* branch(const std::size_t&) const
+         {
+            return branch_[0].first;
+         }
+
+      private:
+
+         bov_node(const bov_node<T,Operation>&);
+         bov_node<T,Operation>& operator=(const bov_node<T,Operation>&);
+
+         const T& v_;
+         branch_t branch_[1];
+      };
+
+      template <typename T, typename Operation>
+      class cob_node : public cob_base_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+         typedef std::pair<expression_ptr,bool> branch_t;
+         typedef Operation operation_t;
+
+         // variable op constant node
+         explicit cob_node(const T const_var, const expression_ptr brnch)
+         : c_(const_var)
+         {
+            init_branches<1>(branch_,brnch);
+         }
+
+        ~cob_node()
+         {
+            cleanup_branches::execute<T,1>(branch_);
+         }
+
+         inline T value() const
+         {
+            return Operation::process(c_,branch_[0].first->value());
+         }
+
+         inline operator_type operation() const
+         {
+            return Operation::operation();
+         }
+
+         inline const T c() const
+         {
+            return c_;
+         }
+
+         inline void set_c(const T new_c)
+         {
+            (*const_cast<T*>(&c_)) = new_c;
+         }
+
+         inline expression_node<T>* branch(const std::size_t&) const
+         {
+            return branch_[0].first;
+         }
+
+         inline expression_node<T>* move_branch(const std::size_t&)
+         {
+            branch_[0].second = false;
+            return branch_[0].first;
+         }
+
+      private:
+
+         cob_node(const cob_node<T,Operation>&);
+         cob_node<T,Operation>& operator=(const cob_node<T,Operation>&);
+
+         const T  c_;
+         branch_t branch_[1];
+      };
+
+      template <typename T, typename Operation>
+      class boc_node : public boc_base_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+         typedef std::pair<expression_ptr,bool> branch_t;
+         typedef Operation operation_t;
+
+         // variable op constant node
+         explicit boc_node(const expression_ptr brnch, const T const_var)
+         : c_(const_var)
+         {
+            init_branches<1>(branch_,brnch);
+         }
+
+        ~boc_node()
+         {
+            cleanup_branches::execute<T,1>(branch_);
+         }
+
+         inline T value() const
+         {
+            return Operation::process(branch_[0].first->value(),c_);
+         }
+
+         inline operator_type operation() const
+         {
+            return Operation::operation();
+         }
+
+         inline const T c() const
+         {
+            return c_;
+         }
+
+         inline void set_c(const T new_c)
+         {
+            (*const_cast<T*>(&c_)) = new_c;
+         }
+
+         inline expression_node<T>* branch(const std::size_t&) const
+         {
+            return branch_[0].first;
+         }
+
+         inline expression_node<T>* move_branch(const std::size_t&)
+         {
+            branch_[0].second = false;
+            return branch_[0].first;
+         }
+
+      private:
+
+         boc_node(const boc_node<T,Operation>&);
+         boc_node<T,Operation>& operator=(const boc_node<T,Operation>&);
+
+         const T  c_;
+         branch_t branch_[1];
+      };
+
+      #ifndef exprtk_disable_string_capabilities
+      template <typename T, typename SType0, typename SType1, typename Operation>
+      class sos_node : public sos_base_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+         typedef Operation operation_t;
+
+         // string op string node
+         explicit sos_node(SType0 p0, SType1 p1)
+         : s0_(p0),
+           s1_(p1)
+         {}
+
+         inline T value() const
+         {
+            return Operation::process(s0_,s1_);
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return Operation::type();
+         }
+
+         inline operator_type operation() const
+         {
+            return Operation::operation();
+         }
+
+         inline std::string& s0()
+         {
+            return s0_;
+         }
+
+         inline std::string& s1()
+         {
+            return s1_;
+         }
+
+      protected:
+
+         SType0 s0_;
+         SType1 s1_;
+
+      private:
+
+         sos_node(sos_node<T,SType0,SType1,Operation>&);
+         sos_node<T,SType0,SType1,Operation>& operator=(sos_node<T,SType0,SType1,Operation>&);
+      };
+
+      template <typename T, typename SType0, typename SType1, typename RangePack, typename Operation>
+      class str_xrox_node : public sos_base_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+         typedef Operation operation_t;
+
+         // string-range op string node
+         explicit str_xrox_node(SType0 p0, SType1 p1, RangePack rp0)
+         : s0_ (p0 ),
+           s1_ (p1 ),
+           rp0_(rp0)
+         {}
+
+        ~str_xrox_node()
+         {
+            rp0_.free();
+         }
+
+         inline T value() const
+         {
+            std::size_t r0 = 0;
+            std::size_t r1 = 0;
+
+            if (rp0_(r0, r1, s0_.size()))
+               return Operation::process(s0_.substr(r0, (r1 - r0) + 1), s1_);
+            else
+               return T(0);
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return Operation::type();
+         }
+
+         inline operator_type operation() const
+         {
+            return Operation::operation();
+         }
+
+         inline std::string& s0()
+         {
+            return s0_;
+         }
+
+         inline std::string& s1()
+         {
+            return s1_;
+         }
+
+      protected:
+
+         SType0    s0_;
+         SType1    s1_;
+         RangePack rp0_;
+
+      private:
+
+         str_xrox_node(str_xrox_node<T,SType0,SType1,RangePack,Operation>&);
+         str_xrox_node<T,SType0,SType1,RangePack,Operation>& operator=(str_xrox_node<T,SType0,SType1,RangePack,Operation>&);
+      };
+
+      template <typename T, typename SType0, typename SType1, typename RangePack, typename Operation>
+      class str_xoxr_node : public sos_base_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+         typedef Operation operation_t;
+
+         // string op string range node
+         explicit str_xoxr_node(SType0 p0, SType1 p1, RangePack rp1)
+         : s0_ (p0 ),
+           s1_ (p1 ),
+           rp1_(rp1)
+         {}
+
+        ~str_xoxr_node()
+         {
+            rp1_.free();
+         }
+
+         inline T value() const
+         {
+            std::size_t r0 = 0;
+            std::size_t r1 = 0;
+
+            if (rp1_(r0, r1, s1_.size()))
+               return Operation::process(s0_, s1_.substr(r0, (r1 - r0) + 1));
+            else
+               return T(0);
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return Operation::type();
+         }
+
+         inline operator_type operation() const
+         {
+            return Operation::operation();
+         }
+
+         inline std::string& s0()
+         {
+            return s0_;
+         }
+
+         inline std::string& s1()
+         {
+            return s1_;
+         }
+
+      protected:
+
+         SType0    s0_;
+         SType1    s1_;
+         RangePack rp1_;
+
+      private:
+
+         str_xoxr_node(str_xoxr_node<T,SType0,SType1,RangePack,Operation>&);
+         str_xoxr_node<T,SType0,SType1,RangePack,Operation>& operator=(str_xoxr_node<T,SType0,SType1,RangePack,Operation>&);
+      };
+
+      template <typename T, typename SType0, typename SType1, typename RangePack, typename Operation>
+      class str_xroxr_node : public sos_base_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+         typedef Operation operation_t;
+
+         // string-range op string-range node
+         explicit str_xroxr_node(SType0 p0, SType1 p1, RangePack rp0, RangePack rp1)
+         : s0_ (p0 ),
+           s1_ (p1 ),
+           rp0_(rp0),
+           rp1_(rp1)
+         {}
+
+        ~str_xroxr_node()
+         {
+            rp0_.free();
+            rp1_.free();
+         }
+
+         inline T value() const
+         {
+            std::size_t r0_0 = 0;
+            std::size_t r0_1 = 0;
+            std::size_t r1_0 = 0;
+            std::size_t r1_1 = 0;
+
+            if (
+                 rp0_(r0_0, r1_0, s0_.size()) &&
+                 rp1_(r0_1, r1_1, s1_.size())
+               )
+            {
+               return Operation::process(
+                                          s0_.substr(r0_0, (r1_0 - r0_0) + 1),
+                                          s1_.substr(r0_1, (r1_1 - r0_1) + 1)
+                                        );
+            }
+            else
+               return T(0);
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return Operation::type();
+         }
+
+         inline operator_type operation() const
+         {
+            return Operation::operation();
+         }
+
+         inline std::string& s0()
+         {
+            return s0_;
+         }
+
+         inline std::string& s1()
+         {
+            return s1_;
+         }
+
+      protected:
+
+         SType0    s0_;
+         SType1    s1_;
+         RangePack rp0_;
+         RangePack rp1_;
+
+      private:
+
+         str_xroxr_node(str_xroxr_node<T,SType0,SType1,RangePack,Operation>&);
+         str_xroxr_node<T,SType0,SType1,RangePack,Operation>& operator=(str_xroxr_node<T,SType0,SType1,RangePack,Operation>&);
+      };
+
+      template <typename T, typename Operation>
+      class str_sogens_node : public binary_node<T>
+      {
+      public:
+
+         typedef expression_node <T>* expression_ptr;
+         typedef string_base_node<T>*   str_base_ptr;
+         typedef range_pack      <T>         range_t;
+         typedef range_t*                  range_ptr;
+         typedef range_interface<T>         irange_t;
+         typedef irange_t*                irange_ptr;
+
+         str_sogens_node(const operator_type& opr,
+                         expression_ptr branch0,
+                         expression_ptr branch1)
+         : binary_node<T>(opr, branch0, branch1),
+           str0_base_ptr_ (0),
+           str1_base_ptr_ (0),
+           str0_range_ptr_(0),
+           str1_range_ptr_(0)
+         {
+            if (is_generally_string_node(binary_node<T>::branch_[0].first))
+            {
+               str0_base_ptr_ = dynamic_cast<str_base_ptr>(binary_node<T>::branch_[0].first);
+
+               if (0 == str0_base_ptr_)
+                  return;
+
+               irange_ptr range = dynamic_cast<irange_ptr>(binary_node<T>::branch_[0].first);
+
+               if (0 == range)
+                  return;
+
+               str0_range_ptr_ = &(range->range_ref());
+            }
+
+            if (is_generally_string_node(binary_node<T>::branch_[1].first))
+            {
+               str1_base_ptr_ = dynamic_cast<str_base_ptr>(binary_node<T>::branch_[1].first);
+
+               if (0 == str1_base_ptr_)
+                  return;
+
+               irange_ptr range = dynamic_cast<irange_ptr>(binary_node<T>::branch_[1].first);
+
+               if (0 == range)
+                  return;
+
+               str1_range_ptr_ = &(range->range_ref());
+            }
+         }
+
+         inline T value() const
+         {
+            if (
+                 str0_base_ptr_  &&
+                 str1_base_ptr_  &&
+                 str0_range_ptr_ &&
+                 str1_range_ptr_
+               )
+            {
+               binary_node<T>::branch_[0].first->value();
+               binary_node<T>::branch_[1].first->value();
+
+               std::size_t str0_r0 = 0;
+               std::size_t str0_r1 = 0;
+
+               std::size_t str1_r0 = 0;
+               std::size_t str1_r1 = 0;
+
+               range_t& range0 = (*str0_range_ptr_);
+               range_t& range1 = (*str1_range_ptr_);
+
+               if (
+                    range0(str0_r0, str0_r1, str0_base_ptr_->size()) &&
+                    range1(str1_r0, str1_r1, str1_base_ptr_->size())
+                  )
+               {
+                  return Operation::process(
+                                             str0_base_ptr_->str().substr(str0_r0,(str0_r1 - str0_r0) + 1),
+                                             str1_base_ptr_->str().substr(str1_r0,(str1_r1 - str1_r0) + 1)
+                                           );
+               }
+            }
+
+            return std::numeric_limits<T>::quiet_NaN();
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return Operation::type();
+         }
+
+         inline operator_type operation() const
+         {
+            return Operation::operation();
+         }
+
+      private:
+
+         str_sogens_node(str_sogens_node<T,Operation>&);
+         str_sogens_node<T,Operation>& operator=(str_sogens_node<T,Operation>&);
+
+         str_base_ptr str0_base_ptr_;
+         str_base_ptr str1_base_ptr_;
+         range_ptr    str0_range_ptr_;
+         range_ptr    str1_range_ptr_;
+      };
+
+      template <typename T, typename SType0, typename SType1, typename SType2, typename Operation>
+      class sosos_node : public sosos_base_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+         typedef Operation operation_t;
+
+         // variable op variable node
+         explicit sosos_node(SType0 p0, SType1 p1, SType2 p2)
+         : s0_(p0),
+           s1_(p1),
+           s2_(p2)
+         {}
+
+         inline T value() const
+         {
+            return Operation::process(s0_,s1_,s2_);
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return Operation::type();
+         }
+
+         inline operator_type operation() const
+         {
+            return Operation::operation();
+         }
+
+         inline std::string& s0()
+         {
+            return s0_;
+         }
+
+         inline std::string& s1()
+         {
+            return s1_;
+         }
+
+         inline std::string& s2()
+         {
+            return s2_;
+         }
+
+      protected:
+
+         SType0 s0_;
+         SType1 s1_;
+         SType2 s2_;
+
+      private:
+
+         sosos_node(sosos_node<T,SType0,SType1,SType2,Operation>&);
+         sosos_node<T,SType0,SType1,SType2,Operation>& operator=(sosos_node<T,SType0,SType1,SType2,Operation>&);
+      };
+      #endif
+
+      template <typename T, typename PowOp>
+      class ipow_node : public expression_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+         typedef PowOp operation_t;
+
+         explicit ipow_node(const T& v)
+         : v_(v)
+         {}
+
+         inline T value() const
+         {
+            return PowOp::result(v_);
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_ipow;
+         }
+
+      private:
+
+         ipow_node(const ipow_node<T,PowOp>&);
+         ipow_node<T,PowOp>& operator=(const ipow_node<T,PowOp>&);
+
+         const T& v_;
+      };
+
+      template <typename T, typename PowOp>
+      class bipow_node : public expression_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+         typedef std::pair<expression_ptr, bool> branch_t;
+         typedef PowOp operation_t;
+
+         explicit bipow_node(expression_ptr brnch)
+         {
+            init_branches<1>(branch_, brnch);
+         }
+
+        ~bipow_node()
+         {
+            cleanup_branches::execute<T,1>(branch_);
+         }
+
+         inline T value() const
+         {
+            return PowOp::result(branch_[0].first->value());
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_ipow;
+         }
+
+      private:
+
+         bipow_node(const bipow_node<T,PowOp>&);
+         bipow_node<T,PowOp>& operator=(const bipow_node<T,PowOp>&);
+
+         branch_t branch_[1];
+      };
+
+      template <typename T, typename PowOp>
+      class ipowinv_node : public expression_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+         typedef PowOp operation_t;
+
+         explicit ipowinv_node(const T& v)
+         : v_(v)
+         {}
+
+         inline T value() const
+         {
+            return (T(1) / PowOp::result(v_));
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_ipowinv;
+         }
+
+      private:
+
+         ipowinv_node(const ipowinv_node<T,PowOp>&);
+         ipowinv_node<T,PowOp>& operator=(const ipowinv_node<T,PowOp>&);
+
+         const T& v_;
+      };
+
+      template <typename T, typename PowOp>
+      class bipowninv_node : public expression_node<T>
+      {
+      public:
+
+         typedef expression_node<T>* expression_ptr;
+         typedef std::pair<expression_ptr, bool> branch_t;
+         typedef PowOp operation_t;
+
+         explicit bipowninv_node(expression_ptr brnch)
+         {
+            init_branches<1>(branch_, brnch);
+         }
+
+        ~bipowninv_node()
+         {
+            cleanup_branches::execute<T,1>(branch_);
+         }
+
+         inline T value() const
+         {
+            return (T(1) / PowOp::result(branch_[0].first->value()));
+         }
+
+         inline typename expression_node<T>::node_type type() const
+         {
+            return expression_node<T>::e_ipowinv;
+         }
+
+      private:
+
+         bipowninv_node(const bipowninv_node<T,PowOp>&);
+         bipowninv_node<T,PowOp>& operator=(const bipowninv_node<T,PowOp>&);
+
+         branch_t branch_[1];
+      };
+
+      template <typename T>
+      inline bool is_vov_node(const expression_node<T>* node)
+      {
+         return (0 != dynamic_cast<const vov_base_node<T>*>(node));
+      }
+
+      template <typename T>
+      inline bool is_cov_node(const expression_node<T>* node)
+      {
+         return (0 != dynamic_cast<const cov_base_node<T>*>(node));
+      }
+
+      template <typename T>
+      inline bool is_voc_node(const expression_node<T>* node)
+      {
+         return (0 != dynamic_cast<const voc_base_node<T>*>(node));
+      }
+
+      template <typename T>
+      inline bool is_cob_node(const expression_node<T>* node)
+      {
+         return (0 != dynamic_cast<const cob_base_node<T>*>(node));
+      }
+
+      template <typename T>
+      inline bool is_boc_node(const expression_node<T>* node)
+      {
+         return (0 != dynamic_cast<const boc_base_node<T>*>(node));
+      }
+
+      template <typename T>
+      inline bool is_t0ot1ot2_node(const expression_node<T>* node)
+      {
+         return (0 != dynamic_cast<const T0oT1oT2_base_node<T>*>(node));
+      }
+
+      template <typename T>
+      inline bool is_t0ot1ot2ot3_node(const expression_node<T>* node)
+      {
+         return (0 != dynamic_cast<const T0oT1oT2oT3_base_node<T>*>(node));
+      }
+
+      template <typename T>
+      inline bool is_uv_node(const expression_node<T>* node)
+      {
+         return (0 != dynamic_cast<const uv_base_node<T>*>(node));
+      }
+
+      template <typename T>
+      inline bool is_string_node(const expression_node<T>* node)
+      {
+         return node && (expression_node<T>::e_stringvar == node->type());
+      }
+
+      template <typename T>
+      inline bool is_string_range_node(const expression_node<T>* node)
+      {
+         return node && (expression_node<T>::e_stringvarrng == node->type());
+      }
+
+      template <typename T>
+      inline bool is_const_string_node(const expression_node<T>* node)
+      {
+         return node && (expression_node<T>::e_stringconst == node->type());
+      }
+
+      template <typename T>
+      inline bool is_const_string_range_node(const expression_node<T>* node)
+      {
+         return node && (expression_node<T>::e_cstringvarrng == node->type());
+      }
+
+      template <typename T>
+      inline bool is_string_assignment_node(const expression_node<T>* node)
+      {
+         return node && (expression_node<T>::e_strass == node->type());
+      }
+
+      template <typename T>
+      inline bool is_string_concat_node(const expression_node<T>* node)
+      {
+         return node && (expression_node<T>::e_strconcat == node->type());
+      }
+
+      template <typename T>
+      inline bool is_string_function_node(const expression_node<T>* node)
+      {
+         return node && (expression_node<T>::e_strfunction == node->type());
+      }
+
+      template <typename T>
+      inline bool is_string_condition_node(const expression_node<T>* node)
+      {
+         return node && (expression_node<T>::e_strcondition == node->type());
+      }
+
+      template <typename T>
+      inline bool is_string_ccondition_node(const expression_node<T>* node)
+      {
+         return node && (expression_node<T>::e_strccondition == node->type());
+      }
+
+      template <typename T>
+      inline bool is_string_vararg_node(const expression_node<T>* node)
+      {
+         return node && (expression_node<T>::e_stringvararg == node->type());
+      }
+
+      template <typename T>
+      inline bool is_genricstring_range_node(const expression_node<T>* node)
+      {
+         return node && (expression_node<T>::e_strgenrange == node->type());
+      }
+
+      template <typename T>
+      inline bool is_generally_string_node(const expression_node<T>* node)
+      {
+         if (node)
+         {
+            switch (node->type())
+            {
+               case expression_node<T>::e_stringvar     :
+               case expression_node<T>::e_stringconst   :
+               case expression_node<T>::e_stringvarrng  :
+               case expression_node<T>::e_cstringvarrng :
+               case expression_node<T>::e_strgenrange   :
+               case expression_node<T>::e_strass        :
+               case expression_node<T>::e_strconcat     :
+               case expression_node<T>::e_strfunction   :
+               case expression_node<T>::e_strcondition  :
+               case expression_node<T>::e_strccondition :
+               case expression_node<T>::e_stringvararg  : return true;
+               default                                  : return false;
+            }
+         }
+
+         return false;
+      }
+
+      class node_allocator
+      {
+      public:
+
+         template <typename ResultNode, typename OpType, typename ExprNode>
+         inline expression_node<typename ResultNode::value_type>* allocate(OpType& operation, ExprNode (&branch)[1])
+         {
+            return allocate<ResultNode>(operation, branch[0]);
+         }
+
+         template <typename ResultNode, typename OpType, typename ExprNode>
+         inline expression_node<typename ResultNode::value_type>* allocate(OpType& operation, ExprNode (&branch)[2])
+         {
+            return allocate<ResultNode>(operation, branch[0], branch[1]);
+         }
+
+         template <typename ResultNode, typename OpType, typename ExprNode>
+         inline expression_node<typename ResultNode::value_type>* allocate(OpType& operation, ExprNode (&branch)[3])
+         {
+            return allocate<ResultNode>(operation, branch[0], branch[1], branch[2]);
+         }
+
+         template <typename ResultNode, typename OpType, typename ExprNode>
+         inline expression_node<typename ResultNode::value_type>* allocate(OpType& operation, ExprNode (&branch)[4])
+         {
+            return allocate<ResultNode>(operation, branch[0], branch[1], branch[2], branch[3]);
+         }
+
+         template <typename ResultNode, typename OpType, typename ExprNode>
+         inline expression_node<typename ResultNode::value_type>* allocate(OpType& operation, ExprNode (&branch)[5])
+         {
+            return allocate<ResultNode>(operation, branch[0],branch[1], branch[2], branch[3], branch[4]);
+         }
+
+         template <typename ResultNode, typename OpType, typename ExprNode>
+         inline expression_node<typename ResultNode::value_type>* allocate(OpType& operation, ExprNode (&branch)[6])
+         {
+            return allocate<ResultNode>(operation, branch[0], branch[1], branch[2], branch[3], branch[4], branch[5]);
+         }
+
+         template <typename node_type>
+         inline expression_node<typename node_type::value_type>* allocate() const
+         {
+            return (new node_type());
+         }
+
+         template <typename node_type,
+                   typename Type,
+                   typename Allocator,
+                   template <typename, typename> class Sequence>
+         inline expression_node<typename node_type::value_type>* allocate(const Sequence<Type,Allocator>& seq) const
+         {
+            return (new node_type(seq));
+         }
+
+         template <typename node_type, typename T1>
+         inline expression_node<typename node_type::value_type>* allocate(T1& t1) const
+         {
+            return (new node_type(t1));
+         }
+
+         template <typename node_type, typename T1>
+         inline expression_node<typename node_type::value_type>* allocate_c(const T1& t1) const
+         {
+            return (new node_type(t1));
+         }
+
+         template <typename node_type,
+                   typename T1, typename T2>
+         inline expression_node<typename node_type::value_type>* allocate(const T1& t1, const T2& t2) const
+         {
+            return (new node_type(t1, t2));
+         }
+
+         template <typename node_type,
+                   typename T1, typename T2>
+         inline expression_node<typename node_type::value_type>* allocate_cr(const T1& t1, T2& t2) const
+         {
+            return (new node_type(t1, t2));
+         }
+
+         template <typename node_type,
+                   typename T1, typename T2>
+         inline expression_node<typename node_type::value_type>* allocate_rc(T1& t1, const T2& t2) const
+         {
+            return (new node_type(t1, t2));
+         }
+
+         template <typename node_type,
+                   typename T1, typename T2>
+         inline expression_node<typename node_type::value_type>* allocate_rr(T1& t1, T2& t2) const
+         {
+            return (new node_type(t1, t2));
+         }
+
+         template <typename node_type,
+                   typename T1, typename T2>
+         inline expression_node<typename node_type::value_type>* allocate_tt(T1 t1, T2 t2) const
+         {
+            return (new node_type(t1, t2));
+         }
+
+         template <typename node_type,
+                   typename T1, typename T2, typename T3>
+         inline expression_node<typename node_type::value_type>* allocate_ttt(T1 t1, T2 t2, T3 t3) const
+         {
+            return (new node_type(t1, t2, t3));
+         }
+
+         template <typename node_type,
+                   typename T1, typename T2, typename T3, typename T4>
+         inline expression_node<typename node_type::value_type>* allocate_tttt(T1 t1, T2 t2, T3 t3, T4 t4) const
+         {
+            return (new node_type(t1, t2, t3, t4));
+         }
+
+         template <typename node_type,
+                   typename T1, typename T2, typename T3>
+         inline expression_node<typename node_type::value_type>* allocate_rrr(T1& t1, T2& t2, T3& t3) const
+         {
+            return (new node_type(t1, t2, t3));
+         }
+
+         template <typename node_type,
+                   typename T1, typename T2, typename T3, typename T4>
+         inline expression_node<typename node_type::value_type>* allocate_rrrr(T1& t1, T2& t2, T3& t3, T4& t4) const
+         {
+            return (new node_type(t1, t2, t3, t4));
+         }
+
+         template <typename node_type,
+                   typename T1, typename T2, typename T3, typename T4, typename T5>
+         inline expression_node<typename node_type::value_type>* allocate_rrrrr(T1& t1, T2& t2, T3& t3, T4& t4, T5& t5) const
+         {
+            return (new node_type(t1, t2, t3, t4, t5));
+         }
+
+         template <typename node_type,
+                   typename T1, typename T2, typename T3>
+         inline expression_node<typename node_type::value_type>* allocate(const T1& t1, const T2& t2,
+                                                                          const T3& t3) const
+         {
+            return (new node_type(t1, t2, t3));
+         }
+
+         template <typename node_type,
+                   typename T1, typename T2,
+                   typename T3, typename T4>
+         inline expression_node<typename node_type::value_type>* allocate(const T1& t1, const T2& t2,
+                                                                          const T3& t3, const T4& t4) const
+         {
+            return (new node_type(t1, t2, t3, t4));
+         }
+
+         template <typename node_type,
+                   typename T1, typename T2,
+                   typename T3, typename T4, typename T5>
+         inline expression_node<typename node_type::value_type>* allocate(const T1& t1, const T2& t2,
+                                                                          const T3& t3, const T4& t4,
+                                                                          const T5& t5) const
+         {
+            return (new node_type(t1, t2, t3, t4, t5));
+         }
+
+         template <typename node_type,
+                   typename T1, typename T2,
+                   typename T3, typename T4, typename T5, typename T6>
+         inline expression_node<typename node_type::value_type>* allocate(const T1& t1, const T2& t2,
+                                                                          const T3& t3, const T4& t4,
+                                                                          const T5& t5, const T6& t6) const
+         {
+            return (new node_type(t1, t2, t3, t4, t5, t6));
+         }
+
+         template <typename node_type,
+                   typename T1, typename T2,
+                   typename T3, typename T4,
+                   typename T5, typename T6, typename T7>
+         inline expression_node<typename node_type::value_type>* allocate(const T1& t1, const T2& t2,
+                                                                          const T3& t3, const T4& t4,
+                                                                          const T5& t5, const T6& t6,
+                                                                          const T7& t7) const
+         {
+            return (new node_type(t1, t2, t3, t4, t5, t6, t7));
+         }
+
+         template <typename node_type,
+                   typename T1, typename T2,
+                   typename T3, typename T4,
+                   typename T5, typename T6,
+                   typename T7, typename T8>
+         inline expression_node<typename node_type::value_type>* allocate(const T1& t1, const T2& t2,
+                                                                          const T3& t3, const T4& t4,
+                                                                          const T5& t5, const T6& t6,
+                                                                          const T7& t7, const T8& t8) const
+         {
+            return (new node_type(t1, t2, t3, t4, t5, t6, t7, t8));
+         }
+
+         template <typename node_type,
+                   typename T1, typename T2,
+                   typename T3, typename T4,
+                   typename T5, typename T6,
+                   typename T7, typename T8, typename T9>
+         inline expression_node<typename node_type::value_type>* allocate(const T1& t1, const T2& t2,
+                                                                          const T3& t3, const T4& t4,
+                                                                          const T5& t5, const T6& t6,
+                                                                          const T7& t7, const T8& t8,
+                                                                          const T9& t9) const
+         {
+            return (new node_type(t1, t2, t3, t4, t5, t6, t7, t8, t9));
+         }
+
+         template <typename node_type,
+                   typename T1, typename T2,
+                   typename T3, typename T4,
+                   typename T5, typename T6,
+                   typename T7, typename T8,
+                   typename T9, typename T10>
+         inline expression_node<typename node_type::value_type>* allocate(const T1& t1, const  T2&  t2,
+                                                                          const T3& t3, const  T4&  t4,
+                                                                          const T5& t5, const  T6&  t6,
+                                                                          const T7& t7, const  T8&  t8,
+                                                                          const T9& t9, const T10& t10) const
+         {
+            return (new node_type(t1, t2, t3, t4, t5, t6, t7, t8, t9, t10));
+         }
+
+         template <typename node_type,
+                   typename T1, typename T2, typename T3>
+         inline expression_node<typename node_type::value_type>* allocate_type(T1 t1, T2 t2, T3 t3) const
+         {
+            return (new node_type(t1, t2, t3));
+         }
+
+         template <typename node_type,
+                   typename T1, typename T2,
+                   typename T3, typename T4>
+         inline expression_node<typename node_type::value_type>* allocate_type(T1 t1, T2 t2,
+                                                                               T3 t3, T4 t4) const
+         {
+            return (new node_type(t1, t2, t3, t4));
+         }
+
+         template <typename node_type,
+                   typename T1, typename T2,
+                   typename T3, typename T4,
+                   typename T5>
+         inline expression_node<typename node_type::value_type>* allocate_type(T1 t1, T2 t2,
+                                                                               T3 t3, T4 t4,
+                                                                               T5 t5) const
+         {
+            return (new node_type(t1, t2, t3, t4, t5));
+         }
+
+         template <typename node_type,
+                   typename T1, typename T2,
+                   typename T3, typename T4,
+                   typename T5, typename T6>
+         inline expression_node<typename node_type::value_type>* allocate_type(T1 t1, T2 t2,
+                                                                               T3 t3, T4 t4,
+                                                                               T5 t5, T6 t6) const
+         {
+            return (new node_type(t1, t2, t3, t4, t5, t6));
+         }
+
+         template <typename node_type,
+                   typename T1, typename T2,
+                   typename T3, typename T4,
+                   typename T5, typename T6, typename T7>
+         inline expression_node<typename node_type::value_type>* allocate_type(T1 t1, T2 t2,
+                                                                               T3 t3, T4 t4,
+                                                                               T5 t5, T6 t6,
+                                                                               T7 t7) const
+         {
+            return (new node_type(t1, t2, t3, t4, t5, t6, t7));
+         }
+
+         template <typename T>
+         void inline free(expression_node<T>*& e) const
+         {
+            delete e;
+            e = 0;
+         }
+      };
+
+      inline void load_operations_map(std::multimap<std::string,details::base_operation_t,details::ilesscompare>& m)
+      {
+         #define register_op(Symbol,Type,Args)                                               \
+         m.insert(std::make_pair(std::string(Symbol),details::base_operation_t(Type,Args))); \
+
+         register_op(      "abs", e_abs     , 1)
+         register_op(     "acos", e_acos    , 1)
+         register_op(    "acosh", e_acosh   , 1)
+         register_op(     "asin", e_asin    , 1)
+         register_op(    "asinh", e_asinh   , 1)
+         register_op(     "atan", e_atan    , 1)
+         register_op(    "atanh", e_atanh   , 1)
+         register_op(     "ceil", e_ceil    , 1)
+         register_op(      "cos", e_cos     , 1)
+         register_op(     "cosh", e_cosh    , 1)
+         register_op(      "exp", e_exp     , 1)
+         register_op(    "expm1", e_expm1   , 1)
+         register_op(    "floor", e_floor   , 1)
+         register_op(      "log", e_log     , 1)
+         register_op(    "log10", e_log10   , 1)
+         register_op(     "log2", e_log2    , 1)
+         register_op(    "log1p", e_log1p   , 1)
+         register_op(    "round", e_round   , 1)
+         register_op(      "sin", e_sin     , 1)
+         register_op(     "sinc", e_sinc    , 1)
+         register_op(     "sinh", e_sinh    , 1)
+         register_op(      "sec", e_sec     , 1)
+         register_op(      "csc", e_csc     , 1)
+         register_op(     "sqrt", e_sqrt    , 1)
+         register_op(      "tan", e_tan     , 1)
+         register_op(     "tanh", e_tanh    , 1)
+         register_op(      "cot", e_cot     , 1)
+         register_op(  "rad2deg", e_r2d     , 1)
+         register_op(  "deg2rad", e_d2r     , 1)
+         register_op( "deg2grad", e_d2g     , 1)
+         register_op( "grad2deg", e_g2d     , 1)
+         register_op(      "sgn", e_sgn     , 1)
+         register_op(      "not", e_notl    , 1)
+         register_op(      "erf", e_erf     , 1)
+         register_op(     "erfc", e_erfc    , 1)
+         register_op(     "ncdf", e_ncdf    , 1)
+         register_op(     "frac", e_frac    , 1)
+         register_op(    "trunc", e_trunc   , 1)
+         register_op(    "atan2", e_atan2   , 2)
+         register_op(      "mod", e_mod     , 2)
+         register_op(     "logn", e_logn    , 2)
+         register_op(      "pow", e_pow     , 2)
+         register_op(     "root", e_root    , 2)
+         register_op(   "roundn", e_roundn  , 2)
+         register_op(    "equal", e_equal   , 2)
+         register_op("not_equal", e_nequal  , 2)
+         register_op(    "hypot", e_hypot   , 2)
+         register_op(      "shr", e_shr     , 2)
+         register_op(      "shl", e_shl     , 2)
+         register_op(    "clamp", e_clamp   , 3)
+         register_op(   "iclamp", e_iclamp  , 3)
+         register_op(  "inrange", e_inrange , 3)
+         #undef register_op
+      }
+
+   } // namespace details
+
+   class function_traits
+   {
+   public:
+
+      function_traits()
+      : allow_zero_parameters_(false),
+        has_side_effects_(true),
+        min_num_args_(0),
+        max_num_args_(std::numeric_limits<std::size_t>::max())
+      {}
+
+      inline bool& allow_zero_parameters()
+      {
+         return allow_zero_parameters_;
+      }
+
+      inline bool& has_side_effects()
+      {
+         return has_side_effects_;
+      }
+
+      std::size_t& min_num_args()
+      {
+         return min_num_args_;
+      }
+
+      std::size_t& max_num_args()
+      {
+         return max_num_args_;
+      }
+
+   private:
+
+      bool allow_zero_parameters_;
+      bool has_side_effects_;
+      std::size_t min_num_args_;
+      std::size_t max_num_args_;
+   };
+
+   template <typename FunctionType>
+   void enable_zero_parameters(FunctionType& func)
+   {
+      func.allow_zero_parameters() = true;
+
+      if (0 != func.min_num_args())
+      {
+         func.min_num_args() = 0;
+      }
+   }
+
+   template <typename FunctionType>
+   void disable_zero_parameters(FunctionType& func)
+   {
+      func.allow_zero_parameters() = false;
+   }
+
+   template <typename FunctionType>
+   void enable_has_side_effects(FunctionType& func)
+   {
+      func.has_side_effects() = true;
+   }
+
+   template <typename FunctionType>
+   void disable_has_side_effects(FunctionType& func)
+   {
+      func.has_side_effects() = false;
+   }
+
+   template <typename FunctionType>
+   void set_min_num_args(FunctionType& func, const std::size_t& num_args)
+   {
+      func.min_num_args() = num_args;
+
+      if ((0 != func.min_num_args()) && func.allow_zero_parameters())
+         func.allow_zero_parameters() = false;
+   }
+
+   template <typename FunctionType>
+   void set_max_num_args(FunctionType& func, const std::size_t& num_args)
+   {
+      func.max_num_args() = num_args;
+   }
+
+   template <typename T>
+   class ifunction : public function_traits
+   {
+   public:
+
+      explicit ifunction(const std::size_t& pc)
+      : param_count(pc)
+      {}
+
+      virtual ~ifunction()
+      {}
+
+      #define empty_method_body                      \
+      {                                              \
+         return std::numeric_limits<T>::quiet_NaN(); \
+      }                                              \
+
+      inline virtual T operator() ()
+      empty_method_body
+
+       inline virtual T operator() (const T&)
+      empty_method_body
+
+       inline virtual T operator() (const T&,const T&)
+      empty_method_body
+
+       inline virtual T operator() (const T&, const T&, const T&)
+      empty_method_body
+
+      inline virtual T operator() (const T&, const T&, const T&, const T&)
+      empty_method_body
+
+      inline virtual T operator() (const T&, const T&, const T&, const T&, const T&)
+      empty_method_body
+
+      inline virtual T operator() (const T&, const T&, const T&, const T&, const T&, const T&)
+      empty_method_body
+
+      inline virtual T operator() (const T&, const T&, const T&, const T&, const T&, const T&, const T&)
+      empty_method_body
+
+      inline virtual T operator() (const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&)
+      empty_method_body
+
+      inline virtual T operator() (const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&)
+      empty_method_body
+
+      inline virtual T operator() (const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&)
+      empty_method_body
+
+      inline virtual T operator() (const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&,
+                                  const T&)
+      empty_method_body
+
+      inline virtual T operator() (const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&,
+                                   const T&, const T&)
+      empty_method_body
+
+      inline virtual T operator() (const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&,
+                                   const T&, const T&, const T&)
+      empty_method_body
+
+      inline virtual T operator() (const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&,
+                                   const T&, const T&, const T&, const T&)
+      empty_method_body
+
+      inline virtual T operator() (const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&,
+                                   const T&, const T&, const T&, const T&, const T&)
+      empty_method_body
+
+      inline virtual T operator() (const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&,
+                                   const T&, const T&, const T&, const T&, const T&, const T&)
+      empty_method_body
+
+      inline virtual T operator() (const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&,
+                                   const T&, const T&, const T&, const T&, const T&, const T&, const T&)
+      empty_method_body
+
+      inline virtual T operator() (const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&,
+                                   const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&)
+      empty_method_body
+
+      inline virtual T operator() (const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&,
+                                   const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&)
+      empty_method_body
+
+      inline virtual T operator() (const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&,
+                                   const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&, const T&)
+      empty_method_body
+
+      #undef empty_method_body
+
+      std::size_t param_count;
+   };
+
+   template <typename T>
+   class ivararg_function : public function_traits
+   {
+   public:
+
+      virtual ~ivararg_function()
+      {}
+
+      inline virtual T operator() (const std::vector<T>&)
+      {
+         exprtk_debug(("ivararg_function::operator() - Operator has not been overridden.\n"));
+         return std::numeric_limits<T>::quiet_NaN();
+      }
+   };
+
+   template <typename T>
+   class igeneric_function : public function_traits
+   {
+   public:
+
+      enum return_type
+      {
+         e_rtrn_scalar   = 0,
+         e_rtrn_string   = 1,
+         e_rtrn_overload = 2
+      };
+
+      typedef T type;
+      typedef type_store<T> generic_type;
+      typedef typename generic_type::parameter_list parameter_list_t;
+
+      igeneric_function(const std::string& param_seq = "", const return_type rtr_type = e_rtrn_scalar)
+      : parameter_sequence(param_seq),
+        rtrn_type(rtr_type)
+      {}
+
+      virtual ~igeneric_function()
+      {}
+
+      #define igeneric_function_empty_body(N)        \
+      {                                              \
+         exprtk_debug(("igeneric_function::operator() - Operator has not been overridden. ["#N"]\n")); \
+         return std::numeric_limits<T>::quiet_NaN(); \
+      }                                              \
+
+      // f(i_0,i_1,....,i_N) --> Scalar
+      inline virtual T operator() (parameter_list_t)
+      igeneric_function_empty_body(1)
+
+      // f(i_0,i_1,....,i_N) --> String
+      inline virtual T operator() (std::string&, parameter_list_t)
+      igeneric_function_empty_body(2)
+
+      // f(psi,i_0,i_1,....,i_N) --> Scalar
+      inline virtual T operator() (const std::size_t&, parameter_list_t)
+      igeneric_function_empty_body(3)
+
+      // f(psi,i_0,i_1,....,i_N) --> String
+      inline virtual T operator() (const std::size_t&, std::string&, parameter_list_t)
+      igeneric_function_empty_body(4)
+
+      std::string parameter_sequence;
+      return_type rtrn_type;
+   };
+
+   template <typename T> class parser;
+   template <typename T> class expression_helper;
+
+   template <typename T>
+   class symbol_table
+   {
+   public:
+
+      typedef T (*ff00_functor)();
+      typedef T (*ff01_functor)(T);
+      typedef T (*ff02_functor)(T, T);
+      typedef T (*ff03_functor)(T, T, T);
+      typedef T (*ff04_functor)(T, T, T, T);
+      typedef T (*ff05_functor)(T, T, T, T, T);
+      typedef T (*ff06_functor)(T, T, T, T, T, T);
+      typedef T (*ff07_functor)(T, T, T, T, T, T, T);
+      typedef T (*ff08_functor)(T, T, T, T, T, T, T, T);
+      typedef T (*ff09_functor)(T, T, T, T, T, T, T, T, T);
+      typedef T (*ff10_functor)(T, T, T, T, T, T, T, T, T, T);
+      typedef T (*ff11_functor)(T, T, T, T, T, T, T, T, T, T, T);
+      typedef T (*ff12_functor)(T, T, T, T, T, T, T, T, T, T, T, T);
+      typedef T (*ff13_functor)(T, T, T, T, T, T, T, T, T, T, T, T, T);
+      typedef T (*ff14_functor)(T, T, T, T, T, T, T, T, T, T, T, T, T, T);
+      typedef T (*ff15_functor)(T, T, T, T, T, T, T, T, T, T, T, T, T, T, T);
+
+   protected:
+
+       struct freefunc00 : public exprtk::ifunction<T>
+       {
+          using exprtk::ifunction<T>::operator();
+
+          explicit freefunc00(ff00_functor ff) : exprtk::ifunction<T>(0), f(ff) {}
+          inline T operator() ()
+          { return f(); }
+          ff00_functor f;
+       };
+
+      struct freefunc01 : public exprtk::ifunction<T>
+      {
+         using exprtk::ifunction<T>::operator();
+
+         explicit freefunc01(ff01_functor ff) : exprtk::ifunction<T>(1), f(ff) {}
+         inline T operator() (const T& v0)
+         { return f(v0); }
+         ff01_functor f;
+      };
+
+      struct freefunc02 : public exprtk::ifunction<T>
+      {
+         using exprtk::ifunction<T>::operator();
+
+         explicit freefunc02(ff02_functor ff) : exprtk::ifunction<T>(2), f(ff) {}
+         inline T operator() (const T& v0, const T& v1)
+         { return f(v0, v1); }
+         ff02_functor f;
+      };
+
+      struct freefunc03 : public exprtk::ifunction<T>
+      {
+         using exprtk::ifunction<T>::operator();
+
+         explicit freefunc03(ff03_functor ff) : exprtk::ifunction<T>(3), f(ff) {}
+         inline T operator() (const T& v0, const T& v1, const T& v2)
+         { return f(v0, v1, v2); }
+         ff03_functor f;
+      };
+
+      struct freefunc04 : public exprtk::ifunction<T>
+      {
+         using exprtk::ifunction<T>::operator();
+
+         explicit freefunc04(ff04_functor ff) : exprtk::ifunction<T>(4), f(ff) {}
+         inline T operator() (const T& v0, const T& v1, const T& v2, const T& v3)
+         { return f(v0, v1, v2, v3); }
+         ff04_functor f;
+      };
+
+      struct freefunc05 : public exprtk::ifunction<T>
+      {
+         using exprtk::ifunction<T>::operator();
+
+         explicit freefunc05(ff05_functor ff) : exprtk::ifunction<T>(5), f(ff) {}
+         inline T operator() (const T& v0, const T& v1, const T& v2, const T& v3, const T& v4)
+         { return f(v0, v1, v2, v3, v4); }
+         ff05_functor f;
+      };
+
+      struct freefunc06 : public exprtk::ifunction<T>
+      {
+         using exprtk::ifunction<T>::operator();
+
+         explicit freefunc06(ff06_functor ff) : exprtk::ifunction<T>(6), f(ff) {}
+         inline T operator() (const T& v0, const T& v1, const T& v2, const T& v3, const T& v4, const T& v5)
+         { return f(v0, v1, v2, v3, v4, v5); }
+         ff06_functor f;
+      };
+
+      struct freefunc07 : public exprtk::ifunction<T>
+      {
+         using exprtk::ifunction<T>::operator();
+
+         explicit freefunc07(ff07_functor ff) : exprtk::ifunction<T>(7), f(ff) {}
+         inline T operator() (const T& v0, const T& v1, const T& v2, const T& v3, const T& v4,
+                              const T& v5, const T& v6)
+         { return f(v0, v1, v2, v3, v4, v5, v6); }
+         ff07_functor f;
+      };
+
+      struct freefunc08 : public exprtk::ifunction<T>
+      {
+         using exprtk::ifunction<T>::operator();
+
+         explicit freefunc08(ff08_functor ff) : exprtk::ifunction<T>(8), f(ff) {}
+         inline T operator() (const T& v0, const T& v1, const T& v2, const T& v3, const T& v4,
+                              const T& v5, const T& v6, const T& v7)
+         { return f(v0, v1, v2, v3, v4, v5, v6, v7); }
+         ff08_functor f;
+      };
+
+      struct freefunc09 : public exprtk::ifunction<T>
+      {
+         using exprtk::ifunction<T>::operator();
+
+         explicit freefunc09(ff09_functor ff) : exprtk::ifunction<T>(9), f(ff) {}
+         inline T operator() (const T& v0, const T& v1, const T& v2, const T& v3, const T& v4,
+                              const T& v5, const T& v6, const T& v7, const T& v8)
+         { return f(v0, v1, v2, v3, v4, v5, v6, v7, v8); }
+         ff09_functor f;
+      };
+
+      struct freefunc10 : public exprtk::ifunction<T>
+      {
+         using exprtk::ifunction<T>::operator();
+
+         explicit freefunc10(ff10_functor ff) : exprtk::ifunction<T>(10), f(ff) {}
+         inline T operator() (const T& v0, const T& v1, const T& v2, const T& v3, const T& v4,
+                              const T& v5, const T& v6, const T& v7, const T& v8, const T& v9)
+         { return f(v0, v1, v2, v3, v4, v5, v6, v7, v8, v9); }
+         ff10_functor f;
+      };
+
+      struct freefunc11 : public exprtk::ifunction<T>
+      {
+         using exprtk::ifunction<T>::operator();
+
+         explicit freefunc11(ff11_functor ff) : exprtk::ifunction<T>(11), f(ff) {}
+         inline T operator() (const T& v0, const T& v1, const T& v2, const T& v3, const T& v4,
+                              const T& v5, const T& v6, const T& v7, const T& v8, const T& v9, const T& v10)
+         { return f(v0, v1, v2, v3, v4, v5, v6, v7, v8, v9, v10); }
+         ff11_functor f;
+      };
+
+      struct freefunc12 : public exprtk::ifunction<T>
+      {
+         using exprtk::ifunction<T>::operator();
+
+         explicit freefunc12(ff12_functor ff) : exprtk::ifunction<T>(12), f(ff) {}
+         inline T operator() (const T& v00, const T& v01, const T& v02, const T& v03, const T& v04,
+                              const T& v05, const T& v06, const T& v07, const T& v08, const T& v09,
+                              const T& v10, const T& v11)
+         { return f(v00, v01, v02, v03, v04, v05, v06, v07, v08, v09, v10, v11); }
+         ff12_functor f;
+      };
+
+      struct freefunc13 : public exprtk::ifunction<T>
+      {
+         using exprtk::ifunction<T>::operator();
+
+         explicit freefunc13(ff13_functor ff) : exprtk::ifunction<T>(13), f(ff) {}
+         inline T operator() (const T& v00, const T& v01, const T& v02, const T& v03, const T& v04,
+                              const T& v05, const T& v06, const T& v07, const T& v08, const T& v09,
+                              const T& v10, const T& v11, const T& v12)
+         { return f(v00, v01, v02, v03, v04, v05, v06, v07, v08, v09, v10, v11, v12); }
+         ff13_functor f;
+      };
+
+      struct freefunc14 : public exprtk::ifunction<T>
+      {
+         using exprtk::ifunction<T>::operator();
+
+         explicit freefunc14(ff14_functor ff) : exprtk::ifunction<T>(14), f(ff) {}
+         inline T operator() (const T& v00, const T& v01, const T& v02, const T& v03, const T& v04,
+                              const T& v05, const T& v06, const T& v07, const T& v08, const T& v09,
+                              const T& v10, const T& v11, const T& v12, const T& v13)
+         { return f(v00, v01, v02, v03, v04, v05, v06, v07, v08, v09, v10, v11, v12, v13); }
+         ff14_functor f;
+      };
+
+      struct freefunc15 : public exprtk::ifunction<T>
+      {
+         using exprtk::ifunction<T>::operator();
+
+         explicit freefunc15(ff15_functor ff) : exprtk::ifunction<T>(15), f(ff) {}
+         inline T operator() (const T& v00, const T& v01, const T& v02, const T& v03, const T& v04,
+                              const T& v05, const T& v06, const T& v07, const T& v08, const T& v09,
+                              const T& v10, const T& v11, const T& v12, const T& v13, const T& v14)
+         { return f(v00, v01, v02, v03, v04, v05, v06, v07, v08, v09, v10, v11, v12, v13, v14); }
+         ff15_functor f;
+      };
+
+      template <typename Type, typename RawType>
+      struct type_store
+      {
+         typedef details::expression_node<T>*        expression_ptr;
+         typedef typename details::variable_node<T>  variable_node_t;
+         typedef ifunction<T>                        ifunction_t;
+         typedef ivararg_function<T>                 ivararg_function_t;
+         typedef igeneric_function<T>                igeneric_function_t;
+         typedef details::vector_holder<T>           vector_t;
+         #ifndef exprtk_disable_string_capabilities
+         typedef typename details::stringvar_node<T> stringvar_node_t;
+         #endif
+
+         typedef Type type_t;
+         typedef type_t* type_ptr;
+         typedef std::pair<bool,type_ptr> type_pair_t;
+         typedef std::map<std::string,type_pair_t,details::ilesscompare> type_map_t;
+         typedef typename type_map_t::iterator tm_itr_t;
+         typedef typename type_map_t::const_iterator tm_const_itr_t;
+
+         enum { lut_size = 256 };
+
+         type_map_t  map;
+         std::size_t size;
+
+         type_store()
+         : size(0)
+         {}
+
+         inline bool symbol_exists(const std::string& symbol_name) const
+         {
+            if (symbol_name.empty())
+               return false;
+            else if (map.end() != map.find(symbol_name))
+               return true;
+            else
+               return false;
+         }
+
+         template <typename PtrType>
+         inline std::string entity_name(const PtrType& ptr) const
+         {
+            if (map.empty())
+               return std::string();
+
+            tm_const_itr_t itr = map.begin();
+
+            while (map.end() != itr)
+            {
+               if (itr->second.second == ptr)
+               {
+                  return itr->first;
+               }
+               else
+                  ++itr;
+            }
+
+            return std::string();
+         }
+
+         inline bool is_constant(const std::string& symbol_name) const
+         {
+            if (symbol_name.empty())
+               return false;
+            else
+            {
+               const tm_const_itr_t itr = map.find(symbol_name);
+
+               if (map.end() == itr)
+                  return false;
+               else
+                  return (*itr).second.first;
+            }
+         }
+
+         template <typename Tie, typename RType>
+         inline bool add_impl(const std::string& symbol_name, RType t, const bool is_const)
+         {
+            if (symbol_name.size() > 1)
+            {
+               for (std::size_t i = 0; i < details::reserved_symbols_size; ++i)
+               {
+                  if (details::imatch(symbol_name, details::reserved_symbols[i]))
+                  {
+                     return false;
+                  }
+               }
+            }
+
+            const tm_itr_t itr = map.find(symbol_name);
+
+            if (map.end() == itr)
+            {
+               map[symbol_name] = Tie::make(t,is_const);
+               ++size;
+            }
+
+            return true;
+         }
+
+         struct tie_array
+         {
+            static inline std::pair<bool,vector_t*> make(std::pair<T*,std::size_t> v, const bool is_const = false)
+            {
+               return std::make_pair(is_const, new vector_t(v.first, v.second));
+            }
+         };
+
+         struct tie_stdvec
+         {
+            template <typename Allocator>
+            static inline std::pair<bool,vector_t*> make(std::vector<T,Allocator>& v, const bool is_const = false)
+            {
+               return std::make_pair(is_const, new vector_t(v));
+            }
+         };
+
+         struct tie_vecview
+         {
+            static inline std::pair<bool,vector_t*> make(exprtk::vector_view<T>& v, const bool is_const = false)
+            {
+               return std::make_pair(is_const, new vector_t(v));
+            }
+         };
+
+         struct tie_stddeq
+         {
+            template <typename Allocator>
+            static inline std::pair<bool,vector_t*> make(std::deque<T,Allocator>& v, const bool is_const = false)
+            {
+               return std::make_pair(is_const, new vector_t(v));
+            }
+         };
+
+         template <std::size_t v_size>
+         inline bool add(const std::string& symbol_name, T (&v)[v_size], const bool is_const = false)
+         {
+            return add_impl<tie_array,std::pair<T*,std::size_t> >
+                      (symbol_name, std::make_pair(v,v_size), is_const);
+         }
+
+         inline bool add(const std::string& symbol_name, T* v, const std::size_t v_size, const bool is_const = false)
+         {
+            return add_impl<tie_array,std::pair<T*,std::size_t> >
+                     (symbol_name, std::make_pair(v,v_size), is_const);
+         }
+
+         template <typename Allocator>
+         inline bool add(const std::string& symbol_name, std::vector<T,Allocator>& v, const bool is_const = false)
+         {
+            return add_impl<tie_stdvec,std::vector<T,Allocator>&>
+                      (symbol_name, v, is_const);
+         }
+
+         inline bool add(const std::string& symbol_name, exprtk::vector_view<T>& v, const bool is_const = false)
+         {
+            return add_impl<tie_vecview,exprtk::vector_view<T>&>
+                      (symbol_name, v, is_const);
+         }
+
+         template <typename Allocator>
+         inline bool add(const std::string& symbol_name, std::deque<T,Allocator>& v, const bool is_const = false)
+         {
+            return add_impl<tie_stddeq,std::deque<T,Allocator>&>
+                      (symbol_name, v, is_const);
+         }
+
+         inline bool add(const std::string& symbol_name, RawType& t, const bool is_const = false)
+         {
+            struct tie
+            {
+               static inline std::pair<bool,variable_node_t*> make(T& t,const bool is_const = false)
+               {
+                  return std::make_pair(is_const, new variable_node_t(t));
+               }
+
+               #ifndef exprtk_disable_string_capabilities
+               static inline std::pair<bool,stringvar_node_t*> make(std::string& t,const bool is_const = false)
+               {
+                  return std::make_pair(is_const, new stringvar_node_t(t));
+               }
+               #endif
+
+               static inline std::pair<bool,function_t*> make(function_t& t, const bool is_constant = false)
+               {
+                  return std::make_pair(is_constant,&t);
+               }
+
+               static inline std::pair<bool,vararg_function_t*> make(vararg_function_t& t, const bool is_const = false)
+               {
+                  return std::make_pair(is_const,&t);
+               }
+
+               static inline std::pair<bool,generic_function_t*> make(generic_function_t& t, const bool is_constant = false)
+               {
+                  return std::make_pair(is_constant,&t);
+               }
+            };
+
+            const tm_itr_t itr = map.find(symbol_name);
+
+            if (map.end() == itr)
+            {
+               map[symbol_name] = tie::make(t,is_const);
+               ++size;
+            }
+
+            return true;
+         }
+
+         inline type_ptr get(const std::string& symbol_name) const
+         {
+            const tm_const_itr_t itr = map.find(symbol_name);
+
+            if (map.end() == itr)
+               return reinterpret_cast<type_ptr>(0);
+            else
+               return itr->second.second;
+         }
+
+         template <typename TType, typename TRawType, typename PtrType>
+         struct ptr_match
+         {
+            static inline bool test(const PtrType, const void*)
+            {
+               return false;
+            }
+         };
+
+         template <typename TType, typename TRawType>
+         struct ptr_match<TType,TRawType,variable_node_t*>
+         {
+            static inline bool test(const variable_node_t* p, const void* ptr)
+            {
+               exprtk_debug(("ptr_match::test() - %p <--> %p\n",(void*)(&(p->ref())),ptr));
+               return (&(p->ref()) == ptr);
+            }
+         };
+
+         inline type_ptr get_from_varptr(const void* ptr) const
+         {
+            tm_const_itr_t itr = map.begin();
+
+            while (map.end() != itr)
+            {
+               type_ptr ret_ptr = itr->second.second;
+
+               if (ptr_match<Type,RawType,type_ptr>::test(ret_ptr,ptr))
+               {
+                  return ret_ptr;
+               }
+
+               ++itr;
+            }
+
+            return type_ptr(0);
+         }
+
+         inline bool remove(const std::string& symbol_name, const bool delete_node = true)
+         {
+            const tm_itr_t itr = map.find(symbol_name);
+
+            if (map.end() != itr)
+            {
+               struct deleter
+               {
+                  static inline void process(std::pair<bool,variable_node_t*>& n)  { delete n.second; }
+                  static inline void process(std::pair<bool,vector_t*>& n)         { delete n.second; }
+                  #ifndef exprtk_disable_string_capabilities
+                  static inline void process(std::pair<bool,stringvar_node_t*>& n) { delete n.second; }
+                  #endif
+                  static inline void process(std::pair<bool,function_t*>&)         {                  }
+               };
+
+               if (delete_node)
+               {
+                  deleter::process((*itr).second);
+               }
+
+               map.erase(itr);
+               --size;
+
+               return true;
+            }
+            else
+               return false;
+         }
+
+         inline RawType& type_ref(const std::string& symbol_name)
+         {
+            struct init_type
+            {
+               static inline double set(double)           { return (0.0);           }
+               static inline double set(long double)      { return (0.0);           }
+               static inline float  set(float)            { return (0.0f);          }
+               static inline std::string set(std::string) { return std::string(""); }
+            };
+
+            static RawType null_type = init_type::set(RawType());
+
+            const tm_const_itr_t itr = map.find(symbol_name);
+
+            if (map.end() == itr)
+               return null_type;
+            else
+               return itr->second.second->ref();
+         }
+
+         inline void clear(const bool delete_node = true)
+         {
+            struct deleter
+            {
+               static inline void process(std::pair<bool,variable_node_t*>& n)  { delete n.second; }
+               static inline void process(std::pair<bool,vector_t*>& n)         { delete n.second; }
+               static inline void process(std::pair<bool,function_t*>&)         {                  }
+               #ifndef exprtk_disable_string_capabilities
+               static inline void process(std::pair<bool,stringvar_node_t*>& n) { delete n.second; }
+               #endif
+            };
+
+            if (!map.empty())
+            {
+               if (delete_node)
+               {
+                  tm_itr_t itr = map.begin();
+                  tm_itr_t end = map.end  ();
+
+                  while (end != itr)
+                  {
+                     deleter::process((*itr).second);
+                     ++itr;
+                  }
+               }
+
+               map.clear();
+            }
+
+            size = 0;
+         }
+
+         template <typename Allocator,
+                   template <typename, typename> class Sequence>
+         inline std::size_t get_list(Sequence<std::pair<std::string,RawType>,Allocator>& list) const
+         {
+            std::size_t count = 0;
+
+            if (!map.empty())
+            {
+               tm_const_itr_t itr = map.begin();
+               tm_const_itr_t end = map.end  ();
+
+               while (end != itr)
+               {
+                  list.push_back(std::make_pair((*itr).first,itr->second.second->ref()));
+                  ++itr;
+                  ++count;
+               }
+            }
+
+            return count;
+         }
+
+         template <typename Allocator,
+                   template <typename, typename> class Sequence>
+         inline std::size_t get_list(Sequence<std::string,Allocator>& vlist) const
+         {
+            std::size_t count = 0;
+
+            if (!map.empty())
+            {
+               tm_const_itr_t itr = map.begin();
+               tm_const_itr_t end = map.end  ();
+
+               while (end != itr)
+               {
+                  vlist.push_back((*itr).first);
+                  ++itr;
+                  ++count;
+               }
+            }
+
+            return count;
+         }
+      };
+
+      typedef details::expression_node<T>* expression_ptr;
+      typedef typename details::variable_node<T> variable_t;
+      typedef typename details::vector_holder<T> vector_holder_t;
+      typedef variable_t* variable_ptr;
+      #ifndef exprtk_disable_string_capabilities
+      typedef typename details::stringvar_node<T> stringvar_t;
+      typedef stringvar_t* stringvar_ptr;
+      #endif
+      typedef ifunction        <T> function_t;
+      typedef ivararg_function <T> vararg_function_t;
+      typedef igeneric_function<T> generic_function_t;
+      typedef function_t* function_ptr;
+      typedef vararg_function_t*  vararg_function_ptr;
+      typedef generic_function_t* generic_function_ptr;
+
+      static const std::size_t lut_size = 256;
+
+      // Symbol Table Holder
+      struct control_block
+      {
+         struct st_data
+         {
+            type_store<typename details::variable_node<T>,T> variable_store;
+            #ifndef exprtk_disable_string_capabilities
+            type_store<typename details::stringvar_node<T>,std::string> stringvar_store;
+            #endif
+            type_store<ifunction<T>,ifunction<T> >                 function_store;
+            type_store<ivararg_function <T>,ivararg_function <T> > vararg_function_store;
+            type_store<igeneric_function<T>,igeneric_function<T> > generic_function_store;
+            type_store<igeneric_function<T>,igeneric_function<T> > string_function_store;
+            type_store<igeneric_function<T>,igeneric_function<T> > overload_function_store;
+            type_store<vector_holder_t,vector_holder_t>            vector_store;
+
+            st_data()
+            {
+               for (std::size_t i = 0; i < details::reserved_words_size; ++i)
+               {
+                  reserved_symbol_table_.insert(details::reserved_words[i]);
+               }
+
+               for (std::size_t i = 0; i < details::reserved_symbols_size; ++i)
+               {
+                  reserved_symbol_table_.insert(details::reserved_symbols[i]);
+               }
+            }
+
+           ~st_data()
+            {
+               for (std::size_t i = 0; i < free_function_list_.size(); ++i)
+               {
+                  delete free_function_list_[i];
+               }
+            }
+
+            inline bool is_reserved_symbol(const std::string& symbol) const
+            {
+               return (reserved_symbol_table_.end() != reserved_symbol_table_.find(symbol));
+            }
+
+            static inline st_data* create()
+            {
+               return (new st_data);
+            }
+
+            static inline void destroy(st_data*& sd)
+            {
+               delete sd;
+               sd = reinterpret_cast<st_data*>(0);
+            }
+
+            std::list<T>               local_symbol_list_;
+            std::list<std::string>     local_stringvar_list_;
+            std::set<std::string>      reserved_symbol_table_;
+            std::vector<ifunction<T>*> free_function_list_;
+         };
+
+         control_block()
+         : ref_count(1),
+           data_(st_data::create())
+         {}
+
+         explicit control_block(st_data* data)
+         : ref_count(1),
+           data_(data)
+         {}
+
+        ~control_block()
+         {
+            if (data_ && (0 == ref_count))
+            {
+               st_data::destroy(data_);
+            }
+         }
+
+         static inline control_block* create()
+         {
+            return (new control_block);
+         }
+
+         template <typename SymTab>
+         static inline void destroy(control_block*& cntrl_blck, SymTab* sym_tab)
+         {
+            if (cntrl_blck)
+            {
+               if (
+                    (0 !=   cntrl_blck->ref_count) &&
+                    (0 == --cntrl_blck->ref_count)
+                  )
+               {
+                  if (sym_tab)
+                     sym_tab->clear();
+
+                  delete cntrl_blck;
+               }
+
+               cntrl_blck = 0;
+            }
+         }
+
+         std::size_t ref_count;
+         st_data* data_;
+      };
+
+   public:
+
+      symbol_table()
+      : control_block_(control_block::create())
+      {
+         clear();
+      }
+
+     ~symbol_table()
+      {
+         control_block::destroy(control_block_,this);
+      }
+
+      symbol_table(const symbol_table<T>& st)
+      {
+         control_block_ = st.control_block_;
+         control_block_->ref_count++;
+      }
+
+      inline symbol_table<T>& operator=(const symbol_table<T>& st)
+      {
+         if (this != &st)
+         {
+            control_block::destroy(control_block_,reinterpret_cast<symbol_table<T>*>(0));
+
+            control_block_ = st.control_block_;
+            control_block_->ref_count++;
+         }
+
+         return (*this);
+      }
+
+      inline bool operator==(const symbol_table<T>& st) const
+      {
+         return (this == &st) || (control_block_ == st.control_block_);
+      }
+
+      inline void clear_variables(const bool delete_node = true)
+      {
+         local_data().variable_store.clear(delete_node);
+      }
+
+      inline void clear_functions()
+      {
+         local_data().function_store.clear();
+      }
+
+      inline void clear_strings()
+      {
+         #ifndef exprtk_disable_string_capabilities
+         local_data().stringvar_store.clear();
+         #endif
+      }
+
+      inline void clear_vectors()
+      {
+         local_data().vector_store.clear();
+      }
+
+      inline void clear_local_constants()
+      {
+         local_data().local_symbol_list_.clear();
+      }
+
+      inline void clear()
+      {
+         if (!valid()) return;
+         clear_variables      ();
+         clear_functions      ();
+         clear_strings        ();
+         clear_vectors        ();
+         clear_local_constants();
+      }
+
+      inline std::size_t variable_count() const
+      {
+         if (valid())
+            return local_data().variable_store.size;
+         else
+            return 0;
+      }
+
+      #ifndef exprtk_disable_string_capabilities
+      inline std::size_t stringvar_count() const
+      {
+         if (valid())
+            return local_data().stringvar_store.size;
+         else
+            return 0;
+      }
+      #endif
+
+      inline std::size_t function_count() const
+      {
+         if (valid())
+            return local_data().function_store.size;
+         else
+            return 0;
+      }
+
+      inline std::size_t vector_count() const
+      {
+         if (valid())
+            return local_data().vector_store.size;
+         else
+            return 0;
+      }
+
+      inline variable_ptr get_variable(const std::string& variable_name) const
+      {
+         if (!valid())
+            return reinterpret_cast<variable_ptr>(0);
+         else if (!valid_symbol(variable_name))
+            return reinterpret_cast<variable_ptr>(0);
+         else
+            return local_data().variable_store.get(variable_name);
+      }
+
+      inline variable_ptr get_variable(const T& var_ref) const
+      {
+         if (!valid())
+            return reinterpret_cast<variable_ptr>(0);
+         else
+            return local_data().variable_store.get_from_varptr(
+                                                  reinterpret_cast<const void*>(&var_ref));
+      }
+
+      #ifndef exprtk_disable_string_capabilities
+      inline stringvar_ptr get_stringvar(const std::string& string_name) const
+      {
+         if (!valid())
+            return reinterpret_cast<stringvar_ptr>(0);
+         else if (!valid_symbol(string_name))
+            return reinterpret_cast<stringvar_ptr>(0);
+         else
+            return local_data().stringvar_store.get(string_name);
+      }
+      #endif
+
+      inline function_ptr get_function(const std::string& function_name) const
+      {
+         if (!valid())
+            return reinterpret_cast<function_ptr>(0);
+         else if (!valid_symbol(function_name))
+            return reinterpret_cast<function_ptr>(0);
+         else
+            return local_data().function_store.get(function_name);
+      }
+
+      inline vararg_function_ptr get_vararg_function(const std::string& vararg_function_name) const
+      {
+         if (!valid())
+            return reinterpret_cast<vararg_function_ptr>(0);
+         else if (!valid_symbol(vararg_function_name))
+            return reinterpret_cast<vararg_function_ptr>(0);
+         else
+            return local_data().vararg_function_store.get(vararg_function_name);
+      }
+
+      inline generic_function_ptr get_generic_function(const std::string& function_name) const
+      {
+         if (!valid())
+            return reinterpret_cast<generic_function_ptr>(0);
+         else if (!valid_symbol(function_name))
+            return reinterpret_cast<generic_function_ptr>(0);
+         else
+            return local_data().generic_function_store.get(function_name);
+      }
+
+      inline generic_function_ptr get_string_function(const std::string& function_name) const
+      {
+         if (!valid())
+            return reinterpret_cast<generic_function_ptr>(0);
+         else if (!valid_symbol(function_name))
+            return reinterpret_cast<generic_function_ptr>(0);
+         else
+            return local_data().string_function_store.get(function_name);
+      }
+
+      inline generic_function_ptr get_overload_function(const std::string& function_name) const
+      {
+         if (!valid())
+            return reinterpret_cast<generic_function_ptr>(0);
+         else if (!valid_symbol(function_name))
+            return reinterpret_cast<generic_function_ptr>(0);
+         else
+            return local_data().overload_function_store.get(function_name);
+      }
+
+      typedef vector_holder_t* vector_holder_ptr;
+
+      inline vector_holder_ptr get_vector(const std::string& vector_name) const
+      {
+         if (!valid())
+            return reinterpret_cast<vector_holder_ptr>(0);
+         else if (!valid_symbol(vector_name))
+            return reinterpret_cast<vector_holder_ptr>(0);
+         else
+            return local_data().vector_store.get(vector_name);
+      }
+
+      inline T& variable_ref(const std::string& symbol_name)
+      {
+         static T null_var = T(0);
+         if (!valid())
+            return null_var;
+         else if (!valid_symbol(symbol_name))
+            return null_var;
+         else
+            return local_data().variable_store.type_ref(symbol_name);
+      }
+
+      #ifndef exprtk_disable_string_capabilities
+      inline std::string& stringvar_ref(const std::string& symbol_name)
+      {
+         static std::string null_stringvar;
+         if (!valid())
+            return null_stringvar;
+         else if (!valid_symbol(symbol_name))
+            return null_stringvar;
+         else
+            return local_data().stringvar_store.type_ref(symbol_name);
+      }
+      #endif
+
+      inline bool is_constant_node(const std::string& symbol_name) const
+      {
+         if (!valid())
+            return false;
+         else if (!valid_symbol(symbol_name))
+            return false;
+         else
+            return local_data().variable_store.is_constant(symbol_name);
+      }
+
+      #ifndef exprtk_disable_string_capabilities
+      inline bool is_constant_string(const std::string& symbol_name) const
+      {
+         if (!valid())
+            return false;
+         else if (!valid_symbol(symbol_name))
+            return false;
+         else if (!local_data().stringvar_store.symbol_exists(symbol_name))
+            return false;
+         else
+            return local_data().stringvar_store.is_constant(symbol_name);
+      }
+      #endif
+
+      inline bool create_variable(const std::string& variable_name, const T& value = T(0))
+      {
+         if (!valid())
+            return false;
+         else if (!valid_symbol(variable_name))
+            return false;
+         else if (symbol_exists(variable_name))
+            return false;
+
+         local_data().local_symbol_list_.push_back(value);
+         T& t = local_data().local_symbol_list_.back();
+
+         return add_variable(variable_name,t);
+      }
+
+      #ifndef exprtk_disable_string_capabilities
+      inline bool create_stringvar(const std::string& stringvar_name, const std::string& value = std::string(""))
+      {
+         if (!valid())
+            return false;
+         else if (!valid_symbol(stringvar_name))
+            return false;
+         else if (symbol_exists(stringvar_name))
+            return false;
+
+         local_data().local_stringvar_list_.push_back(value);
+         std::string& s = local_data().local_stringvar_list_.back();
+
+         return add_stringvar(stringvar_name,s);
+      }
+      #endif
+
+      inline bool add_variable(const std::string& variable_name, T& t, const bool is_constant = false)
+      {
+         if (!valid())
+            return false;
+         else if (!valid_symbol(variable_name))
+            return false;
+         else if (symbol_exists(variable_name))
+            return false;
+         else
+            return local_data().variable_store.add(variable_name, t, is_constant);
+      }
+
+      inline bool add_constant(const std::string& constant_name, const T& value)
+      {
+         if (!valid())
+            return false;
+         else if (!valid_symbol(constant_name))
+            return false;
+         else if (symbol_exists(constant_name))
+            return false;
+
+         local_data().local_symbol_list_.push_back(value);
+         T& t = local_data().local_symbol_list_.back();
+
+         return add_variable(constant_name, t, true);
+      }
+
+      #ifndef exprtk_disable_string_capabilities
+      inline bool add_stringvar(const std::string& stringvar_name, std::string& s, const bool is_constant = false)
+      {
+         if (!valid())
+            return false;
+         else if (!valid_symbol(stringvar_name))
+            return false;
+         else if (symbol_exists(stringvar_name))
+            return false;
+         else
+            return local_data().stringvar_store.add(stringvar_name, s, is_constant);
+      }
+      #endif
+
+      inline bool add_function(const std::string& function_name, function_t& function)
+      {
+         if (!valid())
+            return false;
+         else if (!valid_symbol(function_name))
+            return false;
+         else if (symbol_exists(function_name))
+            return false;
+         else
+            return local_data().function_store.add(function_name,function);
+      }
+
+      inline bool add_function(const std::string& vararg_function_name, vararg_function_t& vararg_function)
+      {
+         if (!valid())
+            return false;
+         else if (!valid_symbol(vararg_function_name))
+            return false;
+         else if (symbol_exists(vararg_function_name))
+            return false;
+         else
+            return local_data().vararg_function_store.add(vararg_function_name,vararg_function);
+      }
+
+      inline bool add_function(const std::string& function_name, generic_function_t& function)
+      {
+         if (!valid())
+            return false;
+         else if (!valid_symbol(function_name))
+            return false;
+         else if (symbol_exists(function_name))
+            return false;
+         else if (
+                   (
+                     (generic_function_t::e_rtrn_scalar == function.rtrn_type) ||
+                     (generic_function_t::e_rtrn_string == function.rtrn_type)
+                   ) &&
+                   std::string::npos != function.parameter_sequence.find_first_not_of("STVZ*?|")
+                 )
+            return false;
+         else if (
+                   (generic_function_t::e_rtrn_overload  == function.rtrn_type) &&
+                   std::string::npos != function.parameter_sequence.find_first_not_of("STVZ*?|:")
+                 )
+            return false;
+
+         switch (function.rtrn_type)
+         {
+            case generic_function_t::e_rtrn_scalar :
+               return local_data().generic_function_store.add(function_name,function);
+
+            case generic_function_t::e_rtrn_string :
+               return local_data().string_function_store.add(function_name,function);
+
+            case generic_function_t::e_rtrn_overload :
+               return local_data().overload_function_store.add(function_name,function);
+         }
+
+         return false;
+      }
+
+      #define exprtk_define_freefunction(NN)                                                \
+      inline bool add_function(const std::string& function_name, ff##NN##_functor function) \
+      {                                                                                     \
+         if (!valid())                                                                      \
+         { return false; }                                                                  \
+         if (!valid_symbol(function_name))                                                  \
+         { return false; }                                                                  \
+         if (symbol_exists(function_name))                                                  \
+         { return false; }                                                                  \
+                                                                                            \
+         exprtk::ifunction<T>* ifunc = new freefunc##NN(function);                          \
+                                                                                            \
+         local_data().free_function_list_.push_back(ifunc);                                 \
+                                                                                            \
+         return add_function(function_name,(*local_data().free_function_list_.back()));     \
+      }                                                                                     \
+
+      exprtk_define_freefunction(00) exprtk_define_freefunction(01)
+      exprtk_define_freefunction(02) exprtk_define_freefunction(03)
+      exprtk_define_freefunction(04) exprtk_define_freefunction(05)
+      exprtk_define_freefunction(06) exprtk_define_freefunction(07)
+      exprtk_define_freefunction(08) exprtk_define_freefunction(09)
+      exprtk_define_freefunction(10) exprtk_define_freefunction(11)
+      exprtk_define_freefunction(12) exprtk_define_freefunction(13)
+      exprtk_define_freefunction(14) exprtk_define_freefunction(15)
+
+      #undef exprtk_define_freefunction
+
+      inline bool add_reserved_function(const std::string& function_name, function_t& function)
+      {
+         if (!valid())
+            return false;
+         else if (!valid_symbol(function_name,false))
+            return false;
+         else if (symbol_exists(function_name,false))
+            return false;
+         else
+            return local_data().function_store.add(function_name,function);
+      }
+
+      inline bool add_reserved_function(const std::string& vararg_function_name, vararg_function_t& vararg_function)
+      {
+         if (!valid())
+            return false;
+         else if (!valid_symbol(vararg_function_name,false))
+            return false;
+         else if (symbol_exists(vararg_function_name,false))
+            return false;
+         else
+            return local_data().vararg_function_store.add(vararg_function_name,vararg_function);
+      }
+
+      inline bool add_reserved_function(const std::string& function_name, generic_function_t& function)
+      {
+         if (!valid())
+            return false;
+         else if (!valid_symbol(function_name,false))
+            return false;
+         else if (symbol_exists(function_name,false))
+            return false;
+         else if (
+                   (
+                     (generic_function_t::e_rtrn_scalar == function.rtrn_type) ||
+                     (generic_function_t::e_rtrn_string == function.rtrn_type)
+                   ) &&
+                   std::string::npos != function.parameter_sequence.find_first_not_of("STV*?|")
+                 )
+            return false;
+         else if (
+                   generic_function_t::e_rtrn_overload &&
+                   std::string::npos != function.parameter_sequence.find_first_not_of("STV*?|:")
+                 )
+            return false;
+
+         switch (function.rtrn_type)
+         {
+            case generic_function_t::e_rtrn_scalar :
+               return local_data().generic_function_store.add(function_name,function);
+
+            case generic_function_t::e_rtrn_string :
+               return local_data().string_function_store.add(function_name,function);
+
+            case generic_function_t::e_rtrn_overload :
+               return local_data().overload_function_store.add(function_name,function);
+         }
+
+         return false;
+      }
+
+      template <std::size_t N>
+      inline bool add_vector(const std::string& vector_name, T (&v)[N])
+      {
+         if (!valid())
+            return false;
+         else if (!valid_symbol(vector_name))
+            return false;
+         else if (symbol_exists(vector_name))
+            return false;
+         else
+            return local_data().vector_store.add(vector_name,v);
+      }
+
+      inline bool add_vector(const std::string& vector_name, T* v, const std::size_t& v_size)
+      {
+         if (!valid())
+            return false;
+         else if (!valid_symbol(vector_name))
+            return false;
+         else if (symbol_exists(vector_name))
+            return false;
+         else if (0 == v_size)
+            return false;
+         else
+            return local_data().vector_store.add(vector_name, v, v_size);
+      }
+
+      template <typename Allocator>
+      inline bool add_vector(const std::string& vector_name, std::vector<T,Allocator>& v)
+      {
+         if (!valid())
+            return false;
+         else if (!valid_symbol(vector_name))
+            return false;
+         else if (symbol_exists(vector_name))
+            return false;
+         else if (0 == v.size())
+            return false;
+         else
+            return local_data().vector_store.add(vector_name,v);
+      }
+
+      inline bool add_vector(const std::string& vector_name, exprtk::vector_view<T>& v)
+      {
+         if (!valid())
+            return false;
+         else if (!valid_symbol(vector_name))
+            return false;
+         else if (symbol_exists(vector_name))
+            return false;
+         else if (0 == v.size())
+            return false;
+         else
+            return local_data().vector_store.add(vector_name,v);
+      }
+
+      inline bool remove_variable(const std::string& variable_name, const bool delete_node = true)
+      {
+         if (!valid())
+            return false;
+         else
+            return local_data().variable_store.remove(variable_name, delete_node);
+      }
+
+      #ifndef exprtk_disable_string_capabilities
+      inline bool remove_stringvar(const std::string& string_name)
+      {
+         if (!valid())
+            return false;
+         else
+            return local_data().stringvar_store.remove(string_name);
+      }
+      #endif
+
+      inline bool remove_function(const std::string& function_name)
+      {
+         if (!valid())
+            return false;
+         else
+            return local_data().function_store.remove(function_name);
+      }
+
+      inline bool remove_vararg_function(const std::string& vararg_function_name)
+      {
+         if (!valid())
+            return false;
+         else
+            return local_data().vararg_function_store.remove(vararg_function_name);
+      }
+
+      inline bool remove_vector(const std::string& vector_name)
+      {
+         if (!valid())
+            return false;
+         else
+            return local_data().vector_store.remove(vector_name);
+      }
+
+      inline bool add_constants()
+      {
+         return add_pi      () &&
+                add_epsilon () &&
+                add_infinity() ;
+      }
+
+      inline bool add_pi()
+      {
+         const typename details::numeric::details::number_type<T>::type num_type;
+         static const T local_pi = details::numeric::details::const_pi_impl<T>(num_type);
+         return add_constant("pi",local_pi);
+      }
+
+      inline bool add_epsilon()
+      {
+         static const T local_epsilon = details::numeric::details::epsilon_type<T>::value();
+         return add_constant("epsilon",local_epsilon);
+      }
+
+      inline bool add_infinity()
+      {
+         static const T local_infinity = std::numeric_limits<T>::infinity();
+         return add_constant("inf",local_infinity);
+      }
+
+      template <typename Package>
+      inline bool add_package(Package& package)
+      {
+         return package.register_package(*this);
+      }
+
+      template <typename Allocator,
+                template <typename, typename> class Sequence>
+      inline std::size_t get_variable_list(Sequence<std::pair<std::string,T>,Allocator>& vlist) const
+      {
+         if (!valid())
+            return 0;
+         else
+            return local_data().variable_store.get_list(vlist);
+      }
+
+      template <typename Allocator,
+                template <typename, typename> class Sequence>
+      inline std::size_t get_variable_list(Sequence<std::string,Allocator>& vlist) const
+      {
+         if (!valid())
+            return 0;
+         else
+            return local_data().variable_store.get_list(vlist);
+      }
+
+      #ifndef exprtk_disable_string_capabilities
+      template <typename Allocator,
+                template <typename, typename> class Sequence>
+      inline std::size_t get_stringvar_list(Sequence<std::pair<std::string,std::string>,Allocator>& svlist) const
+      {
+         if (!valid())
+            return 0;
+         else
+            return local_data().stringvar_store.get_list(svlist);
+      }
+
+      template <typename Allocator,
+                template <typename, typename> class Sequence>
+      inline std::size_t get_stringvar_list(Sequence<std::string,Allocator>& svlist) const
+      {
+         if (!valid())
+            return 0;
+         else
+            return local_data().stringvar_store.get_list(svlist);
+      }
+      #endif
+
+      template <typename Allocator,
+                template <typename, typename> class Sequence>
+      inline std::size_t get_vector_list(Sequence<std::string,Allocator>& vlist) const
+      {
+         if (!valid())
+            return 0;
+         else
+            return local_data().vector_store.get_list(vlist);
+      }
+
+      inline bool symbol_exists(const std::string& symbol_name, const bool check_reserved_symb = true) const
+      {
+         /*
+            Function will return true if symbol_name exists as either a
+            reserved symbol, variable, stringvar, vector or function name
+            in any of the type stores.
+         */
+         if (!valid())
+            return false;
+         else if (local_data().variable_store.symbol_exists(symbol_name))
+            return true;
+         #ifndef exprtk_disable_string_capabilities
+         else if (local_data().stringvar_store.symbol_exists(symbol_name))
+            return true;
+         #endif
+         else if (local_data().vector_store.symbol_exists(symbol_name))
+            return true;
+         else if (local_data().function_store.symbol_exists(symbol_name))
+            return true;
+         else if (check_reserved_symb && local_data().is_reserved_symbol(symbol_name))
+            return true;
+         else
+            return false;
+      }
+
+      inline bool is_variable(const std::string& variable_name) const
+      {
+         if (!valid())
+            return false;
+         else
+            return local_data().variable_store.symbol_exists(variable_name);
+      }
+
+      #ifndef exprtk_disable_string_capabilities
+      inline bool is_stringvar(const std::string& stringvar_name) const
+      {
+         if (!valid())
+            return false;
+         else
+            return local_data().stringvar_store.symbol_exists(stringvar_name);
+      }
+
+      inline bool is_conststr_stringvar(const std::string& symbol_name) const
+      {
+         if (!valid())
+            return false;
+         else if (!valid_symbol(symbol_name))
+            return false;
+         else if (!local_data().stringvar_store.symbol_exists(symbol_name))
+            return false;
+
+         return (
+                  local_data().stringvar_store.symbol_exists(symbol_name) ||
+                  local_data().stringvar_store.is_constant  (symbol_name)
+                );
+      }
+      #endif
+
+      inline bool is_function(const std::string& function_name) const
+      {
+         if (!valid())
+            return false;
+         else
+            return local_data().function_store.symbol_exists(function_name);
+      }
+
+      inline bool is_vararg_function(const std::string& vararg_function_name) const
+      {
+         if (!valid())
+            return false;
+         else
+            return local_data().vararg_function_store.symbol_exists(vararg_function_name);
+      }
+
+      inline bool is_vector(const std::string& vector_name) const
+      {
+         if (!valid())
+            return false;
+         else
+            return local_data().vector_store.symbol_exists(vector_name);
+      }
+
+      inline std::string get_variable_name(const expression_ptr& ptr) const
+      {
+         return local_data().variable_store.entity_name(ptr);
+      }
+
+      inline std::string get_vector_name(const vector_holder_ptr& ptr) const
+      {
+         return local_data().vector_store.entity_name(ptr);
+      }
+
+      #ifndef exprtk_disable_string_capabilities
+      inline std::string get_stringvar_name(const expression_ptr& ptr) const
+      {
+         return local_data().stringvar_store.entity_name(ptr);
+      }
+
+      inline std::string get_conststr_stringvar_name(const expression_ptr& ptr) const
+      {
+         return local_data().stringvar_store.entity_name(ptr);
+      }
+      #endif
+
+      inline bool valid() const
+      {
+         // Symbol table sanity check.
+         return control_block_ && control_block_->data_;
+      }
+
+      inline void load_from(const symbol_table<T>& st)
+      {
+         {
+            std::vector<std::string> name_list;
+
+            st.local_data().function_store.get_list(name_list);
+
+            if (!name_list.empty())
+            {
+               for (std::size_t i = 0; i < name_list.size(); ++i)
+               {
+                  exprtk::ifunction<T>& ifunc = *st.get_function(name_list[i]);
+                  add_function(name_list[i],ifunc);
+               }
+            }
+         }
+
+         {
+            std::vector<std::string> name_list;
+
+            st.local_data().vararg_function_store.get_list(name_list);
+
+            if (!name_list.empty())
+            {
+               for (std::size_t i = 0; i < name_list.size(); ++i)
+               {
+                  exprtk::ivararg_function<T>& ivafunc = *st.get_vararg_function(name_list[i]);
+                  add_function(name_list[i],ivafunc);
+               }
+            }
+         }
+
+         {
+            std::vector<std::string> name_list;
+
+            st.local_data().generic_function_store.get_list(name_list);
+
+            if (!name_list.empty())
+            {
+               for (std::size_t i = 0; i < name_list.size(); ++i)
+               {
+                  exprtk::igeneric_function<T>& ifunc = *st.get_generic_function(name_list[i]);
+                  add_function(name_list[i],ifunc);
+               }
+            }
+         }
+
+         {
+            std::vector<std::string> name_list;
+
+            st.local_data().string_function_store.get_list(name_list);
+
+            if (!name_list.empty())
+            {
+               for (std::size_t i = 0; i < name_list.size(); ++i)
+               {
+                  exprtk::igeneric_function<T>& ifunc = *st.get_string_function(name_list[i]);
+                  add_function(name_list[i],ifunc);
+               }
+            }
+         }
+
+         {
+            std::vector<std::string> name_list;
+
+            st.local_data().overload_function_store.get_list(name_list);
+
+            if (!name_list.empty())
+            {
+               for (std::size_t i = 0; i < name_list.size(); ++i)
+               {
+                  exprtk::igeneric_function<T>& ifunc = *st.get_overload_function(name_list[i]);
+                  add_function(name_list[i],ifunc);
+               }
+            }
+         }
+      }
+
+   private:
+
+      inline bool valid_symbol(const std::string& symbol, const bool check_reserved_symb = true) const
+      {
+         if (symbol.empty())
+            return false;
+         else if (!details::is_letter(symbol[0]))
+            return false;
+         else if (symbol.size() > 1)
+         {
+            for (std::size_t i = 1; i < symbol.size(); ++i)
+            {
+               if (
+                    !details::is_letter_or_digit(symbol[i]) &&
+                    ('_' != symbol[i])
+                  )
+               {
+                  if (('.' == symbol[i]) && (i < (symbol.size() - 1)))
+                     continue;
+                  else
+                     return false;
+               }
+            }
+         }
+
+         return (check_reserved_symb) ? (!local_data().is_reserved_symbol(symbol)) : true;
+      }
+
+      inline bool valid_function(const std::string& symbol) const
+      {
+         if (symbol.empty())
+            return false;
+         else if (!details::is_letter(symbol[0]))
+            return false;
+         else if (symbol.size() > 1)
+         {
+            for (std::size_t i = 1; i < symbol.size(); ++i)
+            {
+               if (
+                    !details::is_letter_or_digit(symbol[i]) &&
+                    ('_' != symbol[i])
+                  )
+               {
+                  if (('.' == symbol[i]) && (i < (symbol.size() - 1)))
+                     continue;
+                  else
+                     return false;
+               }
+            }
+         }
+
+         return true;
+      }
+
+      typedef typename control_block::st_data local_data_t;
+
+      inline local_data_t& local_data()
+      {
+         return *(control_block_->data_);
+      }
+
+      inline const local_data_t& local_data() const
+      {
+         return *(control_block_->data_);
+      }
+
+      control_block* control_block_;
+
+      friend class parser<T>;
+   };
+
+   template <typename T>
+   class function_compositor;
+
+   template <typename T>
+   class expression
+   {
+   private:
+
+      typedef details::expression_node<T>*  expression_ptr;
+      typedef details::vector_holder<T>* vector_holder_ptr;
+      typedef std::vector<symbol_table<T> >  symtab_list_t;
+
+      struct control_block
+      {
+         enum data_type
+         {
+            e_unknown  ,
+            e_expr     ,
+            e_vecholder,
+            e_data     ,
+            e_vecdata  ,
+            e_string
+         };
+
+         struct data_pack
+         {
+            data_pack()
+            : pointer(0),
+              type(e_unknown),
+              size(0)
+            {}
+
+            data_pack(void* ptr, const data_type dt, const std::size_t sz = 0)
+            : pointer(ptr),
+              type(dt),
+              size(sz)
+            {}
+
+            void*       pointer;
+            data_type   type;
+            std::size_t size;
+         };
+
+         typedef std::vector<data_pack> local_data_list_t;
+         typedef results_context<T>     results_context_t;
+
+         control_block()
+         : ref_count(0),
+           expr     (0),
+           results  (0),
+           retinv_null(false),
+           return_invoked(&retinv_null)
+         {}
+
+         explicit control_block(expression_ptr e)
+         : ref_count(1),
+           expr     (e),
+           results  (0),
+           retinv_null(false),
+           return_invoked(&retinv_null)
+         {}
+
+        ~control_block()
+         {
+            if (expr && details::branch_deletable(expr))
+            {
+               destroy_node(expr);
+            }
+
+            if (!local_data_list.empty())
+            {
+               for (std::size_t i = 0; i < local_data_list.size(); ++i)
+               {
+                  switch (local_data_list[i].type)
+                  {
+                     case e_expr      : delete reinterpret_cast<expression_ptr>(local_data_list[i].pointer);
+                                        break;
+
+                     case e_vecholder : delete reinterpret_cast<vector_holder_ptr>(local_data_list[i].pointer);
+                                        break;
+
+                     case e_data      : delete (T*)(local_data_list[i].pointer);
+                                        break;
+
+                     case e_vecdata   : delete [] (T*)(local_data_list[i].pointer);
+                                        break;
+
+                     case e_string    : delete (std::string*)(local_data_list[i].pointer);
+                                        break;
+
+                     default          : break;
+                  }
+               }
+            }
+
+            if (results)
+            {
+               delete results;
+            }
+         }
+
+         static inline control_block* create(expression_ptr e)
+         {
+            return new control_block(e);
+         }
+
+         static inline void destroy(control_block*& cntrl_blck)
+         {
+            if (cntrl_blck)
+            {
+               if (
+                    (0 !=   cntrl_blck->ref_count) &&
+                    (0 == --cntrl_blck->ref_count)
+                  )
+               {
+                  delete cntrl_blck;
+               }
+
+               cntrl_blck = 0;
+            }
+         }
+
+         std::size_t ref_count;
+         expression_ptr expr;
+         local_data_list_t local_data_list;
+         results_context_t* results;
+         bool  retinv_null;
+         bool* return_invoked;
+
+         friend class function_compositor<T>;
+      };
+
+   public:
+
+      expression()
+      : control_block_(0)
+      {
+         set_expression(new details::null_node<T>());
+      }
+
+      expression(const expression<T>& e)
+      : control_block_    (e.control_block_    ),
+        symbol_table_list_(e.symbol_table_list_)
+      {
+         control_block_->ref_count++;
+      }
+
+      explicit expression(const symbol_table<T>& symbol_table)
+      : control_block_(0)
+      {
+         set_expression(new details::null_node<T>());
+         symbol_table_list_.push_back(symbol_table);
+      }
+
+      inline expression<T>& operator=(const expression<T>& e)
+      {
+         if (this != &e)
+         {
+            if (control_block_)
+            {
+               if (
+                    (0 !=   control_block_->ref_count) &&
+                    (0 == --control_block_->ref_count)
+                  )
+               {
+                  delete control_block_;
+               }
+
+               control_block_ = 0;
+            }
+
+            control_block_ = e.control_block_;
+            control_block_->ref_count++;
+            symbol_table_list_ = e.symbol_table_list_;
+         }
+
+         return *this;
+      }
+
+      inline bool operator==(const expression<T>& e) const
+      {
+         return (this == &e);
+      }
+
+      inline bool operator!() const
+      {
+         return (
+                  (0 == control_block_      ) ||
+                  (0 == control_block_->expr)
+                );
+      }
+
+      inline expression<T>& release()
+      {
+         control_block::destroy(control_block_);
+
+         return (*this);
+      }
+
+     ~expression()
+      {
+         control_block::destroy(control_block_);
+      }
+
+      inline T value() const
+      {
+         return control_block_->expr->value();
+      }
+
+      inline T operator() () const
+      {
+         return value();
+      }
+
+      inline operator T() const
+      {
+         return value();
+      }
+
+      inline operator bool() const
+      {
+         return details::is_true(value());
+      }
+
+      inline void register_symbol_table(symbol_table<T>& st)
+      {
+         symbol_table_list_.push_back(st);
+      }
+
+      inline const symbol_table<T>& get_symbol_table(const std::size_t& index = 0) const
+      {
+         return symbol_table_list_[index];
+      }
+
+      inline symbol_table<T>& get_symbol_table(const std::size_t& index = 0)
+      {
+         return symbol_table_list_[index];
+      }
+
+      typedef results_context<T> results_context_t;
+
+      inline const results_context_t& results() const
+      {
+         if (control_block_->results)
+            return (*control_block_->results);
+         else
+         {
+            static const results_context_t null_results;
+            return null_results;
+         }
+      }
+
+      inline bool return_invoked() const
+      {
+         return (*control_block_->return_invoked);
+      }
+
+   private:
+
+      inline symtab_list_t get_symbol_table_list() const
+      {
+         return symbol_table_list_;
+      }
+
+      inline void set_expression(const expression_ptr expr)
+      {
+         if (expr)
+         {
+            if (control_block_)
+            {
+               if (0 == --control_block_->ref_count)
+               {
+                  delete control_block_;
+               }
+            }
+
+            control_block_ = control_block::create(expr);
+         }
+      }
+
+      inline void register_local_var(expression_ptr expr)
+      {
+         if (expr)
+         {
+            if (control_block_)
+            {
+               control_block_->
+                  local_data_list.push_back(
+                     typename expression<T>::control_block::
+                        data_pack(reinterpret_cast<void*>(expr),
+                                  control_block::e_expr));
+            }
+         }
+      }
+
+      inline void register_local_var(vector_holder_ptr vec_holder)
+      {
+         if (vec_holder)
+         {
+            if (control_block_)
+            {
+               control_block_->
+                  local_data_list.push_back(
+                     typename expression<T>::control_block::
+                        data_pack(reinterpret_cast<void*>(vec_holder),
+                                  control_block::e_vecholder));
+            }
+         }
+      }
+
+      inline void register_local_data(void* data, const std::size_t& size = 0, const std::size_t data_mode = 0)
+      {
+         if (data)
+         {
+            if (control_block_)
+            {
+               typename control_block::data_type dt = control_block::e_data;
+
+               switch (data_mode)
+               {
+                  case 0 : dt = control_block::e_data;    break;
+                  case 1 : dt = control_block::e_vecdata; break;
+                  case 2 : dt = control_block::e_string;  break;
+               }
+
+               control_block_->
+                  local_data_list.push_back(
+                     typename expression<T>::control_block::
+                        data_pack(reinterpret_cast<void*>(data), dt, size));
+            }
+         }
+      }
+
+      inline const typename control_block::local_data_list_t& local_data_list()
+      {
+         if (control_block_)
+         {
+            return control_block_->local_data_list;
+         }
+         else
+         {
+            static typename control_block::local_data_list_t null_local_data_list;
+            return null_local_data_list;
+         }
+      }
+
+      inline void register_return_results(results_context_t* rc)
+      {
+         if (control_block_ && rc)
+         {
+            control_block_->results = rc;
+         }
+      }
+
+      inline void set_retinvk(bool* retinvk_ptr)
+      {
+         if (control_block_)
+         {
+            control_block_->return_invoked = retinvk_ptr;
+         }
+      }
+
+      control_block* control_block_;
+      symtab_list_t  symbol_table_list_;
+
+      friend class parser<T>;
+      friend class expression_helper<T>;
+      friend class function_compositor<T>;
+   };
+
+   template <typename T>
+   class expression_helper
+   {
+   public:
+
+      static inline bool is_constant(const expression<T>& expr)
+      {
+         return details::is_constant_node(expr.control_block_->expr);
+      }
+
+      static inline bool is_variable(const expression<T>& expr)
+      {
+         return details::is_variable_node(expr.control_block_->expr);
+      }
+
+      static inline bool is_unary(const expression<T>& expr)
+      {
+         return details::is_unary_node(expr.control_block_->expr);
+      }
+
+      static inline bool is_binary(const expression<T>& expr)
+      {
+         return details::is_binary_node(expr.control_block_->expr);
+      }
+
+      static inline bool is_function(const expression<T>& expr)
+      {
+         return details::is_function(expr.control_block_->expr);
+      }
+
+      static inline bool is_null(const expression<T>& expr)
+      {
+         return details::is_null_node(expr.control_block_->expr);
+      }
+   };
+
+   template <typename T>
+   inline bool is_valid(const expression<T>& expr)
+   {
+      return !expression_helper<T>::is_null(expr);
+   }
+
+   namespace parser_error
+   {
+      enum error_mode
+      {
+         e_unknown = 0,
+         e_syntax  = 1,
+         e_token   = 2,
+         e_numeric = 4,
+         e_symtab  = 5,
+         e_lexer   = 6,
+         e_helper  = 7
+      };
+
+      struct type
+      {
+         type()
+         : mode(parser_error::e_unknown),
+           line_no  (0),
+           column_no(0)
+         {}
+
+         lexer::token token;
+         error_mode mode;
+         std::string diagnostic;
+         std::string src_location;
+         std::string error_line;
+         std::size_t line_no;
+         std::size_t column_no;
+      };
+
+      inline type make_error(const error_mode mode,
+                             const std::string& diagnostic   = "",
+                             const std::string& src_location = "")
+      {
+         type t;
+         t.mode         = mode;
+         t.token.type   = lexer::token::e_error;
+         t.diagnostic   = diagnostic;
+         t.src_location = src_location;
+         exprtk_debug(("%s\n",diagnostic .c_str()));
+         return t;
+      }
+
+      inline type make_error(const error_mode mode,
+                             const lexer::token& tk,
+                             const std::string& diagnostic   = "",
+                             const std::string& src_location = "")
+      {
+         type t;
+         t.mode       = mode;
+         t.token      = tk;
+         t.diagnostic = diagnostic;
+         t.src_location = src_location;
+         exprtk_debug(("%s\n",diagnostic .c_str()));
+         return t;
+      }
+
+      inline std::string to_str(error_mode mode)
+      {
+         switch (mode)
+         {
+            case e_unknown : return std::string("Unknown Error");
+            case e_syntax  : return std::string("Syntax Error" );
+            case e_token   : return std::string("Token Error"  );
+            case e_numeric : return std::string("Numeric Error");
+            case e_symtab  : return std::string("Symbol Error" );
+            case e_lexer   : return std::string("Lexer Error"  );
+            case e_helper  : return std::string("Helper Error" );
+            default        : return std::string("Unknown Error");
+         }
+      }
+
+      inline bool update_error(type& error, const std::string& expression)
+      {
+         if (
+              expression.empty()                         ||
+              (error.token.position > expression.size()) ||
+              (std::numeric_limits<std::size_t>::max() == error.token.position)
+            )
+         {
+            return false;
+         }
+
+         std::size_t error_line_start = 0;
+
+         for (std::size_t i = error.token.position; i > 0; --i)
+         {
+            const details::char_t c = expression[i];
+
+            if (('\n' == c) || ('\r' == c))
+            {
+               error_line_start = i + 1;
+               break;
+            }
+         }
+
+         std::size_t next_nl_position = std::min(expression.size(),
+                                                 expression.find_first_of('\n',error.token.position + 1));
+
+         error.column_no  = error.token.position - error_line_start;
+         error.error_line = expression.substr(error_line_start,
+                                              next_nl_position - error_line_start);
+
+         error.line_no = 0;
+
+         for (std::size_t i = 0; i < next_nl_position; ++i)
+         {
+            if ('\n' == expression[i])
+               ++error.line_no;
+         }
+
+         return true;
+      }
+
+      inline void dump_error(const type& error)
+      {
+         printf("Position: %02d   Type: [%s]   Msg: %s\n",
+                static_cast<int>(error.token.position),
+                exprtk::parser_error::to_str(error.mode).c_str(),
+                error.diagnostic.c_str());
+      }
+   }
+
+   namespace details
+   {
+      template <typename Parser>
+      inline void disable_type_checking(Parser& p)
+      {
+         p.state_.type_check_enabled = false;
+      }
+   }
+
+   template <typename T>
+   class parser : public lexer::parser_helper
+   {
+   private:
+
+      enum precedence_level
+      {
+         e_level00,
+         e_level01,
+         e_level02,
+         e_level03,
+         e_level04,
+         e_level05,
+         e_level06,
+         e_level07,
+         e_level08,
+         e_level09,
+         e_level10,
+         e_level11,
+         e_level12,
+         e_level13,
+         e_level14
+      };
+
+      typedef const T&                                               cref_t;
+      typedef const T                                               const_t;
+      typedef ifunction                <T>                                F;
+      typedef ivararg_function         <T>                              VAF;
+      typedef igeneric_function        <T>                               GF;
+      typedef ifunction                <T>                      ifunction_t;
+      typedef ivararg_function         <T>               ivararg_function_t;
+      typedef igeneric_function        <T>              igeneric_function_t;
+      typedef details::expression_node <T>                expression_node_t;
+      typedef details::literal_node    <T>                   literal_node_t;
+      typedef details::unary_node      <T>                     unary_node_t;
+      typedef details::binary_node     <T>                    binary_node_t;
+      typedef details::trinary_node    <T>                   trinary_node_t;
+      typedef details::quaternary_node <T>                quaternary_node_t;
+      typedef details::conditional_node<T>               conditional_node_t;
+      typedef details::cons_conditional_node<T>     cons_conditional_node_t;
+      typedef details::while_loop_node <T>                while_loop_node_t;
+      typedef details::repeat_until_loop_node<T>   repeat_until_loop_node_t;
+      typedef details::for_loop_node   <T>                  for_loop_node_t;
+      #ifndef exprtk_disable_break_continue
+      typedef details::while_loop_bc_node <T>          while_loop_bc_node_t;
+      typedef details::repeat_until_loop_bc_node<T> repeat_until_loop_bc_node_t;
+      typedef details::for_loop_bc_node<T>               for_loop_bc_node_t;
+      #endif
+      typedef details::switch_node     <T>                    switch_node_t;
+      typedef details::variable_node   <T>                  variable_node_t;
+      typedef details::vector_elem_node<T>               vector_elem_node_t;
+      typedef details::rebasevector_elem_node<T>   rebasevector_elem_node_t;
+      typedef details::rebasevector_celem_node<T> rebasevector_celem_node_t;
+      typedef details::vector_node     <T>                    vector_node_t;
+      typedef details::range_pack      <T>                          range_t;
+      #ifndef exprtk_disable_string_capabilities
+      typedef details::stringvar_node     <T>              stringvar_node_t;
+      typedef details::string_literal_node<T>         string_literal_node_t;
+      typedef details::string_range_node  <T>           string_range_node_t;
+      typedef details::const_string_range_node<T> const_string_range_node_t;
+      typedef details::generic_string_range_node<T> generic_string_range_node_t;
+      typedef details::string_concat_node <T>          string_concat_node_t;
+      typedef details::assignment_string_node<T>   assignment_string_node_t;
+      typedef details::assignment_string_range_node<T> assignment_string_range_node_t;
+      typedef details::conditional_string_node<T>  conditional_string_node_t;
+      typedef details::cons_conditional_str_node<T> cons_conditional_str_node_t;
+      #endif
+      typedef details::assignment_node<T>                 assignment_node_t;
+      typedef details::assignment_vec_elem_node       <T> assignment_vec_elem_node_t;
+      typedef details::assignment_rebasevec_elem_node <T> assignment_rebasevec_elem_node_t;
+      typedef details::assignment_rebasevec_celem_node<T> assignment_rebasevec_celem_node_t;
+      typedef details::assignment_vec_node     <T>    assignment_vec_node_t;
+      typedef details::assignment_vecvec_node  <T> assignment_vecvec_node_t;
+      typedef details::scand_node<T>                           scand_node_t;
+      typedef details::scor_node<T>                             scor_node_t;
+      typedef lexer::token                                          token_t;
+      typedef expression_node_t*                        expression_node_ptr;
+      typedef expression<T>                                    expression_t;
+      typedef symbol_table<T>                                symbol_table_t;
+      typedef typename expression<T>::symtab_list_t     symbol_table_list_t;
+      typedef details::vector_holder<T>*                  vector_holder_ptr;
+
+      typedef typename details::functor_t<T>            functor_t;
+      typedef typename functor_t::qfunc_t    quaternary_functor_t;
+      typedef typename functor_t::tfunc_t       trinary_functor_t;
+      typedef typename functor_t::bfunc_t        binary_functor_t;
+      typedef typename functor_t::ufunc_t         unary_functor_t;
+
+      typedef details::operator_type operator_t;
+
+      typedef std::map<operator_t,  unary_functor_t>   unary_op_map_t;
+      typedef std::map<operator_t, binary_functor_t>  binary_op_map_t;
+      typedef std::map<operator_t,trinary_functor_t> trinary_op_map_t;
+
+      typedef std::map<std::string,std::pair<trinary_functor_t   ,operator_t> > sf3_map_t;
+      typedef std::map<std::string,std::pair<quaternary_functor_t,operator_t> > sf4_map_t;
+
+      typedef std::map<binary_functor_t,operator_t> inv_binary_op_map_t;
+      typedef std::multimap<std::string,details::base_operation_t,details::ilesscompare> base_ops_map_t;
+      typedef std::set<std::string,details::ilesscompare> disabled_func_set_t;
+
+      typedef details::T0oT1_define<T,  cref_t,  cref_t> vov_t;
+      typedef details::T0oT1_define<T, const_t,  cref_t> cov_t;
+      typedef details::T0oT1_define<T,  cref_t, const_t> voc_t;
+
+      typedef details::T0oT1oT2_define<T,  cref_t,  cref_t,  cref_t> vovov_t;
+      typedef details::T0oT1oT2_define<T,  cref_t,  cref_t, const_t> vovoc_t;
+      typedef details::T0oT1oT2_define<T,  cref_t, const_t,  cref_t> vocov_t;
+      typedef details::T0oT1oT2_define<T, const_t,  cref_t,  cref_t> covov_t;
+      typedef details::T0oT1oT2_define<T, const_t,  cref_t, const_t> covoc_t;
+      typedef details::T0oT1oT2_define<T, const_t, const_t,  cref_t> cocov_t;
+      typedef details::T0oT1oT2_define<T,  cref_t, const_t, const_t> vococ_t;
+
+      typedef details::T0oT1oT2oT3_define<T,  cref_t,  cref_t,  cref_t,  cref_t> vovovov_t;
+      typedef details::T0oT1oT2oT3_define<T,  cref_t,  cref_t,  cref_t, const_t> vovovoc_t;
+      typedef details::T0oT1oT2oT3_define<T,  cref_t,  cref_t, const_t,  cref_t> vovocov_t;
+      typedef details::T0oT1oT2oT3_define<T,  cref_t, const_t,  cref_t,  cref_t> vocovov_t;
+      typedef details::T0oT1oT2oT3_define<T, const_t,  cref_t,  cref_t,  cref_t> covovov_t;
+
+      typedef details::T0oT1oT2oT3_define<T, const_t,  cref_t, const_t,  cref_t> covocov_t;
+      typedef details::T0oT1oT2oT3_define<T,  cref_t, const_t,  cref_t, const_t> vocovoc_t;
+      typedef details::T0oT1oT2oT3_define<T, const_t,  cref_t,  cref_t, const_t> covovoc_t;
+      typedef details::T0oT1oT2oT3_define<T,  cref_t, const_t, const_t,  cref_t> vococov_t;
+
+      typedef results_context<T> results_context_t;
+
+      typedef parser_helper prsrhlpr_t;
+
+      struct scope_element
+      {
+         enum element_type
+         {
+            e_none    ,
+            e_variable,
+            e_vector  ,
+            e_vecelem ,
+            e_string
+         };
+
+         typedef details::vector_holder<T> vector_holder_t;
+         typedef variable_node_t*        variable_node_ptr;
+         typedef vector_holder_t*        vector_holder_ptr;
+         typedef expression_node_t*    expression_node_ptr;
+         #ifndef exprtk_disable_string_capabilities
+         typedef stringvar_node_t*      stringvar_node_ptr;
+         #endif
+
+         scope_element()
+         : name("???"),
+           size (std::numeric_limits<std::size_t>::max()),
+           index(std::numeric_limits<std::size_t>::max()),
+           depth(std::numeric_limits<std::size_t>::max()),
+           ref_count(0),
+           ip_index (0),
+           type (e_none),
+           active(false),
+           data    (0),
+           var_node(0),
+           vec_node(0)
+           #ifndef exprtk_disable_string_capabilities
+           ,str_node(0)
+           #endif
+         {}
+
+         bool operator < (const scope_element& se) const
+         {
+            if (ip_index < se.ip_index)
+               return true;
+            else if (ip_index > se.ip_index)
+               return false;
+            else if (depth < se.depth)
+               return true;
+            else if (depth > se.depth)
+               return false;
+            else if (index < se.index)
+               return true;
+            else if (index > se.index)
+               return false;
+            else
+               return (name < se.name);
+         }
+
+         void clear()
+         {
+            name   = "???";
+            size   = std::numeric_limits<std::size_t>::max();
+            index  = std::numeric_limits<std::size_t>::max();
+            depth  = std::numeric_limits<std::size_t>::max();
+            type   = e_none;
+            active = false;
+            ref_count = 0;
+            ip_index  = 0;
+            data      = 0;
+            var_node  = 0;
+            vec_node  = 0;
+            #ifndef exprtk_disable_string_capabilities
+            str_node  = 0;
+            #endif
+         }
+
+         std::string  name;
+         std::size_t  size;
+         std::size_t  index;
+         std::size_t  depth;
+         std::size_t  ref_count;
+         std::size_t  ip_index;
+         element_type type;
+         bool         active;
+         void*        data;
+         expression_node_ptr var_node;
+         vector_holder_ptr   vec_node;
+         #ifndef exprtk_disable_string_capabilities
+         stringvar_node_ptr str_node;
+         #endif
+      };
+
+      class scope_element_manager
+      {
+      public:
+
+         typedef expression_node_t* expression_node_ptr;
+         typedef variable_node_t*     variable_node_ptr;
+         typedef parser<T>                     parser_t;
+
+         explicit scope_element_manager(parser<T>& p)
+         : parser_(p),
+           input_param_cnt_(0)
+         {}
+
+         inline std::size_t size() const
+         {
+            return element_.size();
+         }
+
+         inline bool empty() const
+         {
+            return element_.empty();
+         }
+
+         inline scope_element& get_element(const std::size_t& index)
+         {
+            if (index < element_.size())
+               return element_[index];
+            else
+               return null_element_;
+         }
+
+         inline scope_element& get_element(const std::string& var_name,
+                                           const std::size_t index = std::numeric_limits<std::size_t>::max())
+         {
+            const std::size_t current_depth = parser_.state_.scope_depth;
+
+            for (std::size_t i = 0; i < element_.size(); ++i)
+            {
+               scope_element& se = element_[i];
+
+               if (se.depth > current_depth)
+                  continue;
+               else if (
+                         details::imatch(se.name, var_name) &&
+                         (se.index == index)
+                       )
+                  return se;
+            }
+
+            return null_element_;
+         }
+
+         inline scope_element& get_active_element(const std::string& var_name,
+                                                  const std::size_t index = std::numeric_limits<std::size_t>::max())
+         {
+            const std::size_t current_depth = parser_.state_.scope_depth;
+
+            for (std::size_t i = 0; i < element_.size(); ++i)
+            {
+               scope_element& se = element_[i];
+
+               if (se.depth > current_depth)
+                  continue;
+               else if (
+                         details::imatch(se.name, var_name) &&
+                         (se.index == index)                &&
+                         (se.active)
+                       )
+                  return se;
+            }
+
+            return null_element_;
+         }
+
+         inline bool add_element(const scope_element& se)
+         {
+            for (std::size_t i = 0; i < element_.size(); ++i)
+            {
+               scope_element& cse = element_[i];
+
+               if (
+                    details::imatch(cse.name, se.name) &&
+                    (cse.depth <= se.depth)            &&
+                    (cse.index == se.index)            &&
+                    (cse.size  == se.size )            &&
+                    (cse.type  == se.type )            &&
+                    (cse.active)
+                  )
+                  return false;
+            }
+
+            element_.push_back(se);
+            std::sort(element_.begin(),element_.end());
+
+            return true;
+         }
+
+         inline void deactivate(const std::size_t& scope_depth)
+         {
+            exprtk_debug(("deactivate() - Scope depth: %d\n",
+                          static_cast<int>(parser_.state_.scope_depth)));
+
+            for (std::size_t i = 0; i < element_.size(); ++i)
+            {
+               scope_element& se = element_[i];
+
+               if (se.active && (se.depth >= scope_depth))
+               {
+                  exprtk_debug(("deactivate() - element[%02d] '%s'\n",
+                                static_cast<int>(i),
+                                se.name.c_str()));
+
+                  se.active = false;
+               }
+            }
+         }
+
+         inline void free_element(scope_element& se)
+         {
+            #ifdef exprtk_enable_debugging
+            exprtk_debug(("free_element() - se[%s]\n", se.name.c_str()));
+            #endif
+
+            switch (se.type)
+            {
+               case scope_element::e_variable   : if (se.data    ) delete (T*) se.data;
+                                                  if (se.var_node) delete se.var_node;
+                                                  break;
+
+               case scope_element::e_vector     : if (se.data    ) delete[] (T*) se.data;
+                                                  if (se.vec_node) delete se.vec_node;
+                                                  break;
+
+               case scope_element::e_vecelem    : if (se.var_node) delete se.var_node;
+                                                  break;
+
+               #ifndef exprtk_disable_string_capabilities
+               case scope_element::e_string     : if (se.data    ) delete (std::string*) se.data;
+                                                  if (se.str_node) delete se.str_node;
+                                                  break;
+               #endif
+
+               default                          : return;
+            }
+
+            se.clear();
+         }
+
+         inline void cleanup()
+         {
+            for (std::size_t i = 0; i < element_.size(); ++i)
+            {
+               free_element(element_[i]);
+            }
+
+            element_.clear();
+
+            input_param_cnt_ = 0;
+         }
+
+         inline std::size_t next_ip_index()
+         {
+            return ++input_param_cnt_;
+         }
+
+         inline expression_node_ptr get_variable(const T& v)
+         {
+            for (std::size_t i = 0; i < element_.size(); ++i)
+            {
+               scope_element& se = element_[i];
+
+               if (
+                    se.active   &&
+                    se.var_node &&
+                    details::is_variable_node(se.var_node)
+                  )
+               {
+                  variable_node_ptr vn = reinterpret_cast<variable_node_ptr>(se.var_node);
+
+                  if (&(vn->ref()) == (&v))
+                  {
+                     return se.var_node;
+                  }
+               }
+            }
+
+            return expression_node_ptr(0);
+         }
+
+      private:
+
+         scope_element_manager& operator=(const scope_element_manager&);
+
+         parser_t& parser_;
+         std::vector<scope_element> element_;
+         scope_element null_element_;
+         std::size_t input_param_cnt_;
+      };
+
+      class scope_handler
+      {
+      public:
+
+         typedef parser<T> parser_t;
+
+         explicit scope_handler(parser<T>& p)
+         : parser_(p)
+         {
+            parser_.state_.scope_depth++;
+            #ifdef exprtk_enable_debugging
+            const std::string depth(2 * parser_.state_.scope_depth,'-');
+            exprtk_debug(("%s> Scope Depth: %02d\n",
+                          depth.c_str(),
+                          static_cast<int>(parser_.state_.scope_depth)));
+            #endif
+         }
+
+        ~scope_handler()
+         {
+            parser_.sem_.deactivate(parser_.state_.scope_depth);
+            parser_.state_.scope_depth--;
+            #ifdef exprtk_enable_debugging
+            const std::string depth(2 * parser_.state_.scope_depth,'-');
+            exprtk_debug(("<%s Scope Depth: %02d\n",
+                          depth.c_str(),
+                          static_cast<int>(parser_.state_.scope_depth)));
+            #endif
+         }
+
+      private:
+
+         scope_handler& operator=(const scope_handler&);
+
+         parser_t& parser_;
+      };
+
+      struct symtab_store
+      {
+         symbol_table_list_t symtab_list_;
+
+         typedef typename symbol_table_t::local_data_t   local_data_t;
+         typedef typename symbol_table_t::variable_ptr   variable_ptr;
+         typedef typename symbol_table_t::function_ptr   function_ptr;
+         #ifndef exprtk_disable_string_capabilities
+         typedef typename symbol_table_t::stringvar_ptr stringvar_ptr;
+         #endif
+         typedef typename symbol_table_t::vector_holder_ptr       vector_holder_ptr;
+         typedef typename symbol_table_t::vararg_function_ptr   vararg_function_ptr;
+         typedef typename symbol_table_t::generic_function_ptr generic_function_ptr;
+
+         inline bool empty() const
+         {
+            return symtab_list_.empty();
+         }
+
+         inline void clear()
+         {
+            symtab_list_.clear();
+         }
+
+         inline bool valid() const
+         {
+            if (!empty())
+            {
+               for (std::size_t i = 0; i < symtab_list_.size(); ++i)
+               {
+                  if (symtab_list_[i].valid())
+                     return true;
+               }
+            }
+
+            return false;
+         }
+
+         inline bool valid_symbol(const std::string& symbol) const
+         {
+            if (!symtab_list_.empty())
+               return symtab_list_[0].valid_symbol(symbol);
+            else
+               return false;
+         }
+
+         inline bool valid_function_name(const std::string& symbol) const
+         {
+            if (!symtab_list_.empty())
+               return symtab_list_[0].valid_function(symbol);
+            else
+               return false;
+         }
+
+         inline variable_ptr get_variable(const std::string& variable_name) const
+         {
+            if (!valid_symbol(variable_name))
+               return reinterpret_cast<variable_ptr>(0);
+
+            variable_ptr result = reinterpret_cast<variable_ptr>(0);
+
+            for (std::size_t i = 0; i < symtab_list_.size(); ++i)
+            {
+               if (!symtab_list_[i].valid())
+                  continue;
+               else
+                  result = local_data(i)
+                              .variable_store.get(variable_name);
+
+               if (result) break;
+            }
+
+            return result;
+         }
+
+         inline variable_ptr get_variable(const T& var_ref) const
+         {
+            variable_ptr result = reinterpret_cast<variable_ptr>(0);
+
+            for (std::size_t i = 0; i < symtab_list_.size(); ++i)
+            {
+               if (!symtab_list_[i].valid())
+                  continue;
+               else
+                  result = local_data(i).variable_store
+                              .get_from_varptr(reinterpret_cast<const void*>(&var_ref));
+
+               if (result) break;
+            }
+
+            return result;
+         }
+
+         #ifndef exprtk_disable_string_capabilities
+         inline stringvar_ptr get_stringvar(const std::string& string_name) const
+         {
+            if (!valid_symbol(string_name))
+               return reinterpret_cast<stringvar_ptr>(0);
+
+            stringvar_ptr result = reinterpret_cast<stringvar_ptr>(0);
+
+            for (std::size_t i = 0; i < symtab_list_.size(); ++i)
+            {
+               if (!symtab_list_[i].valid())
+                  continue;
+               else
+                  result = local_data(i)
+                              .stringvar_store.get(string_name);
+
+               if (result) break;
+            }
+
+            return result;
+         }
+         #endif
+
+         inline function_ptr get_function(const std::string& function_name) const
+         {
+            if (!valid_function_name(function_name))
+               return reinterpret_cast<function_ptr>(0);
+
+            function_ptr result = reinterpret_cast<function_ptr>(0);
+
+            for (std::size_t i = 0; i < symtab_list_.size(); ++i)
+            {
+               if (!symtab_list_[i].valid())
+                  continue;
+               else
+                  result = local_data(i)
+                              .function_store.get(function_name);
+
+               if (result) break;
+            }
+
+            return result;
+         }
+
+         inline vararg_function_ptr get_vararg_function(const std::string& vararg_function_name) const
+         {
+            if (!valid_function_name(vararg_function_name))
+               return reinterpret_cast<vararg_function_ptr>(0);
+
+            vararg_function_ptr result = reinterpret_cast<vararg_function_ptr>(0);
+
+            for (std::size_t i = 0; i < symtab_list_.size(); ++i)
+            {
+               if (!symtab_list_[i].valid())
+                  continue;
+               else
+                  result = local_data(i)
+                              .vararg_function_store.get(vararg_function_name);
+
+               if (result) break;
+            }
+
+            return result;
+         }
+
+         inline generic_function_ptr get_generic_function(const std::string& function_name) const
+         {
+            if (!valid_function_name(function_name))
+               return reinterpret_cast<generic_function_ptr>(0);
+
+            generic_function_ptr result = reinterpret_cast<generic_function_ptr>(0);
+
+            for (std::size_t i = 0; i < symtab_list_.size(); ++i)
+            {
+               if (!symtab_list_[i].valid())
+                  continue;
+               else
+                  result = local_data(i)
+                              .generic_function_store.get(function_name);
+
+               if (result) break;
+            }
+
+            return result;
+         }
+
+         inline generic_function_ptr get_string_function(const std::string& function_name) const
+         {
+            if (!valid_function_name(function_name))
+               return reinterpret_cast<generic_function_ptr>(0);
+
+            generic_function_ptr result = reinterpret_cast<generic_function_ptr>(0);
+
+            for (std::size_t i = 0; i < symtab_list_.size(); ++i)
+            {
+               if (!symtab_list_[i].valid())
+                  continue;
+               else
+                  result =
+                     local_data(i).string_function_store.get(function_name);
+
+               if (result) break;
+            }
+
+            return result;
+         }
+
+         inline generic_function_ptr get_overload_function(const std::string& function_name) const
+         {
+            if (!valid_function_name(function_name))
+               return reinterpret_cast<generic_function_ptr>(0);
+
+            generic_function_ptr result = reinterpret_cast<generic_function_ptr>(0);
+
+            for (std::size_t i = 0; i < symtab_list_.size(); ++i)
+            {
+               if (!symtab_list_[i].valid())
+                  continue;
+               else
+                  result =
+                     local_data(i).overload_function_store.get(function_name);
+
+               if (result) break;
+            }
+
+            return result;
+         }
+
+         inline vector_holder_ptr get_vector(const std::string& vector_name) const
+         {
+            if (!valid_symbol(vector_name))
+               return reinterpret_cast<vector_holder_ptr>(0);
+
+            vector_holder_ptr result = reinterpret_cast<vector_holder_ptr>(0);
+
+            for (std::size_t i = 0; i < symtab_list_.size(); ++i)
+            {
+               if (!symtab_list_[i].valid())
+                  continue;
+               else
+                  result =
+                     local_data(i).vector_store.get(vector_name);
+
+               if (result) break;
+            }
+
+            return result;
+         }
+
+         inline bool is_constant_node(const std::string& symbol_name) const
+         {
+            if (!valid_symbol(symbol_name))
+               return false;
+
+            for (std::size_t i = 0; i < symtab_list_.size(); ++i)
+            {
+               if (!symtab_list_[i].valid())
+                  continue;
+               else if (local_data(i).variable_store.is_constant(symbol_name))
+                  return true;
+            }
+
+            return false;
+         }
+
+         #ifndef exprtk_disable_string_capabilities
+         inline bool is_constant_string(const std::string& symbol_name) const
+         {
+            if (!valid_symbol(symbol_name))
+               return false;
+
+            for (std::size_t i = 0; i < symtab_list_.size(); ++i)
+            {
+               if (!symtab_list_[i].valid())
+                  continue;
+               else if (!local_data(i).stringvar_store.symbol_exists(symbol_name))
+                  continue;
+               else if ( local_data(i).stringvar_store.is_constant(symbol_name))
+                  return true;
+            }
+
+            return false;
+         }
+         #endif
+
+         inline bool symbol_exists(const std::string& symbol) const
+         {
+            for (std::size_t i = 0; i < symtab_list_.size(); ++i)
+            {
+               if (!symtab_list_[i].valid())
+                  continue;
+               else if (symtab_list_[i].symbol_exists(symbol))
+                  return true;
+            }
+
+            return false;
+         }
+
+         inline bool is_variable(const std::string& variable_name) const
+         {
+            for (std::size_t i = 0; i < symtab_list_.size(); ++i)
+            {
+               if (!symtab_list_[i].valid())
+                  continue;
+               else if (
+                         symtab_list_[i].local_data().variable_store
+                           .symbol_exists(variable_name)
+                       )
+                  return true;
+            }
+
+            return false;
+         }
+
+         #ifndef exprtk_disable_string_capabilities
+         inline bool is_stringvar(const std::string& stringvar_name) const
+         {
+            for (std::size_t i = 0; i < symtab_list_.size(); ++i)
+            {
+               if (!symtab_list_[i].valid())
+                  continue;
+               else if (
+                         symtab_list_[i].local_data().stringvar_store
+                           .symbol_exists(stringvar_name)
+                       )
+                  return true;
+            }
+
+            return false;
+         }
+
+         inline bool is_conststr_stringvar(const std::string& symbol_name) const
+         {
+            for (std::size_t i = 0; i < symtab_list_.size(); ++i)
+            {
+               if (!symtab_list_[i].valid())
+                  continue;
+               else if (
+                         symtab_list_[i].local_data().stringvar_store
+                           .symbol_exists(symbol_name)
+                       )
+               {
+                  return (
+                           local_data(i).stringvar_store.symbol_exists(symbol_name) ||
+                           local_data(i).stringvar_store.is_constant  (symbol_name)
+                         );
+
+               }
+            }
+
+            return false;
+         }
+         #endif
+
+         inline bool is_function(const std::string& function_name) const
+         {
+            for (std::size_t i = 0; i < symtab_list_.size(); ++i)
+            {
+               if (!symtab_list_[i].valid())
+                  continue;
+               else if (
+                         local_data(i).vararg_function_store
+                           .symbol_exists(function_name)
+                       )
+                  return true;
+            }
+
+            return false;
+         }
+
+         inline bool is_vararg_function(const std::string& vararg_function_name) const
+         {
+            for (std::size_t i = 0; i < symtab_list_.size(); ++i)
+            {
+               if (!symtab_list_[i].valid())
+                  continue;
+               else if (
+                         local_data(i).vararg_function_store
+                           .symbol_exists(vararg_function_name)
+                       )
+                  return true;
+            }
+
+            return false;
+         }
+
+         inline bool is_vector(const std::string& vector_name) const
+         {
+            for (std::size_t i = 0; i < symtab_list_.size(); ++i)
+            {
+               if (!symtab_list_[i].valid())
+                  continue;
+               else if (
+                         local_data(i).vector_store
+                           .symbol_exists(vector_name)
+                       )
+                  return true;
+            }
+
+            return false;
+         }
+
+         inline std::string get_variable_name(const expression_node_ptr& ptr) const
+         {
+            return local_data().variable_store.entity_name(ptr);
+         }
+
+         inline std::string get_vector_name(const vector_holder_ptr& ptr) const
+         {
+            return local_data().vector_store.entity_name(ptr);
+         }
+
+         #ifndef exprtk_disable_string_capabilities
+         inline std::string get_stringvar_name(const expression_node_ptr& ptr) const
+         {
+            return local_data().stringvar_store.entity_name(ptr);
+         }
+
+         inline std::string get_conststr_stringvar_name(const expression_node_ptr& ptr) const
+         {
+            return local_data().stringvar_store.entity_name(ptr);
+         }
+         #endif
+
+         inline local_data_t& local_data(const std::size_t& index = 0)
+         {
+            return symtab_list_[index].local_data();
+         }
+
+         inline const local_data_t& local_data(const std::size_t& index = 0) const
+         {
+            return symtab_list_[index].local_data();
+         }
+
+         inline symbol_table_t& get_symbol_table(const std::size_t& index = 0)
+         {
+            return symtab_list_[index];
+         }
+      };
+
+      struct parser_state
+      {
+         parser_state()
+         : type_check_enabled(true)
+         {
+            reset();
+         }
+
+         void reset()
+         {
+            parsing_return_stmt = false;
+            parsing_break_stmt  = false;
+            return_stmt_present = false;
+            side_effect_present = false;
+            scope_depth         = 0;
+         }
+
+         #ifndef exprtk_enable_debugging
+         void activate_side_effect(const std::string&)
+         #else
+         void activate_side_effect(const std::string& source)
+         #endif
+         {
+            if (!side_effect_present)
+            {
+               side_effect_present = true;
+
+               exprtk_debug(("activate_side_effect() - caller: %s\n",source.c_str()));
+            }
+         }
+
+         bool parsing_return_stmt;
+         bool parsing_break_stmt;
+         bool return_stmt_present;
+         bool side_effect_present;
+         bool type_check_enabled;
+         std::size_t scope_depth;
+      };
+
+   public:
+
+      struct unknown_symbol_resolver
+      {
+
+         enum usr_symbol_type
+         {
+            e_usr_unknown_type  = 0,
+            e_usr_variable_type = 1,
+            e_usr_constant_type = 2
+         };
+
+         enum usr_mode
+         {
+            e_usrmode_default  = 0,
+            e_usrmode_extended = 1
+         };
+
+         usr_mode mode;
+
+         unknown_symbol_resolver(const usr_mode m = e_usrmode_default)
+         : mode(m)
+         {}
+
+         virtual ~unknown_symbol_resolver()
+         {}
+
+         virtual bool process(const std::string& /*unknown_symbol*/,
+                              usr_symbol_type&   st,
+                              T&                 default_value,
+                              std::string&       error_message)
+         {
+            if (e_usrmode_default != mode)
+               return false;
+
+            st = e_usr_variable_type;
+            default_value = T(0);
+            error_message.clear();
+
+            return true;
+         }
+
+         virtual bool process(const std::string& /* unknown_symbol */,
+                              symbol_table_t&    /* symbol_table   */,
+                              std::string&       /* error_message  */)
+         {
+            return false;
+         }
+      };
+
+      enum collect_type
+      {
+         e_ct_none        = 0,
+         e_ct_variables   = 1,
+         e_ct_functions   = 2,
+         e_ct_assignments = 4
+      };
+
+      enum symbol_type
+      {
+         e_st_unknown        = 0,
+         e_st_variable       = 1,
+         e_st_vector         = 2,
+         e_st_vecelem        = 3,
+         e_st_string         = 4,
+         e_st_function       = 5,
+         e_st_local_variable = 6,
+         e_st_local_vector   = 7,
+         e_st_local_string   = 8
+      };
+
+      class dependent_entity_collector
+      {
+      public:
+
+         typedef std::pair<std::string,symbol_type> symbol_t;
+         typedef std::vector<symbol_t> symbol_list_t;
+
+         dependent_entity_collector(const std::size_t options = e_ct_none)
+         : options_(options),
+           collect_variables_  ((options_ & e_ct_variables  ) == e_ct_variables  ),
+           collect_functions_  ((options_ & e_ct_functions  ) == e_ct_functions  ),
+           collect_assignments_((options_ & e_ct_assignments) == e_ct_assignments),
+           return_present_   (false),
+           final_stmt_return_(false)
+         {}
+
+         template <typename Allocator,
+                   template <typename, typename> class Sequence>
+         inline std::size_t symbols(Sequence<symbol_t,Allocator>& symbols_list)
+         {
+            if (!collect_variables_ && !collect_functions_)
+               return 0;
+            else if (symbol_name_list_.empty())
+               return 0;
+
+            for (std::size_t i = 0; i < symbol_name_list_.size(); ++i)
+            {
+               details::case_normalise(symbol_name_list_[i].first);
+            }
+
+            std::sort(symbol_name_list_.begin(),symbol_name_list_.end());
+
+            std::unique_copy(symbol_name_list_.begin(),
+                             symbol_name_list_.end  (),
+                             std::back_inserter(symbols_list));
+
+            return symbols_list.size();
+         }
+
+         template <typename Allocator,
+                   template <typename, typename> class Sequence>
+         inline std::size_t assignment_symbols(Sequence<symbol_t,Allocator>& assignment_list)
+         {
+            if (!collect_assignments_)
+               return 0;
+            else if (assignment_name_list_.empty())
+               return 0;
+
+            for (std::size_t i = 0; i < assignment_name_list_.size(); ++i)
+            {
+               details::case_normalise(assignment_name_list_[i].first);
+            }
+
+            std::sort(assignment_name_list_.begin(),assignment_name_list_.end());
+
+            std::unique_copy(assignment_name_list_.begin(),
+                             assignment_name_list_.end  (),
+                             std::back_inserter(assignment_list));
+
+            return assignment_list.size();
+         }
+
+         void clear()
+         {
+            symbol_name_list_    .clear();
+            assignment_name_list_.clear();
+            retparam_list_       .clear();
+            return_present_    = false;
+            final_stmt_return_ = false;
+         }
+
+         bool& collect_variables()
+         {
+            return collect_variables_;
+         }
+
+         bool& collect_functions()
+         {
+            return collect_functions_;
+         }
+
+         bool& collect_assignments()
+         {
+            return collect_assignments_;
+         }
+
+         bool return_present() const
+         {
+            return return_present_;
+         }
+
+         bool final_stmt_return() const
+         {
+            return final_stmt_return_;
+         }
+
+         typedef std::vector<std::string> retparam_list_t;
+
+         retparam_list_t return_param_type_list() const
+         {
+            return retparam_list_;
+         }
+
+      private:
+
+         inline void add_symbol(const std::string& symbol, const symbol_type st)
+         {
+            switch (st)
+            {
+               case e_st_variable       :
+               case e_st_vector         :
+               case e_st_string         :
+               case e_st_local_variable :
+               case e_st_local_vector   :
+               case e_st_local_string   : if (collect_variables_)
+                                             symbol_name_list_
+                                                .push_back(std::make_pair(symbol, st));
+                                          break;
+
+               case e_st_function       : if (collect_functions_)
+                                             symbol_name_list_
+                                                .push_back(std::make_pair(symbol, st));
+                                          break;
+
+               default                  : return;
+            }
+         }
+
+         inline void add_assignment(const std::string& symbol, const symbol_type st)
+         {
+            switch (st)
+            {
+               case e_st_variable       :
+               case e_st_vector         :
+               case e_st_string         : if (collect_assignments_)
+                                             assignment_name_list_
+                                                .push_back(std::make_pair(symbol, st));
+                                          break;
+
+               default                  : return;
+            }
+         }
+
+         std::size_t options_;
+         bool collect_variables_;
+         bool collect_functions_;
+         bool collect_assignments_;
+         bool return_present_;
+         bool final_stmt_return_;
+         symbol_list_t symbol_name_list_;
+         symbol_list_t assignment_name_list_;
+         retparam_list_t retparam_list_;
+
+         friend class parser<T>;
+      };
+
+      class settings_store
+      {
+      private:
+
+         typedef std::set<std::string,details::ilesscompare> disabled_entity_set_t;
+         typedef disabled_entity_set_t::iterator des_itr_t;
+
+      public:
+
+         enum settings_compilation_options
+         {
+            e_unknown              =    0,
+            e_replacer             =    1,
+            e_joiner               =    2,
+            e_numeric_check        =    4,
+            e_bracket_check        =    8,
+            e_sequence_check       =   16,
+            e_commutative_check    =   32,
+            e_strength_reduction   =   64,
+            e_disable_vardef       =  128,
+            e_collect_vars         =  256,
+            e_collect_funcs        =  512,
+            e_collect_assings      = 1024,
+            e_disable_usr_on_rsrvd = 2048,
+            e_disable_zero_return  = 4096
+         };
+
+         enum settings_base_funcs
+         {
+            e_bf_unknown = 0,
+            e_bf_abs       , e_bf_acos     , e_bf_acosh    , e_bf_asin   ,
+            e_bf_asinh     , e_bf_atan     , e_bf_atan2    , e_bf_atanh  ,
+            e_bf_avg       , e_bf_ceil     , e_bf_clamp    , e_bf_cos    ,
+            e_bf_cosh      , e_bf_cot      , e_bf_csc      , e_bf_equal  ,
+            e_bf_erf       , e_bf_erfc     , e_bf_exp      , e_bf_expm1  ,
+            e_bf_floor     , e_bf_frac     , e_bf_hypot    , e_bf_iclamp ,
+            e_bf_like      , e_bf_log      , e_bf_log10    , e_bf_log1p  ,
+            e_bf_log2      , e_bf_logn     , e_bf_mand     , e_bf_max    ,
+            e_bf_min       , e_bf_mod      , e_bf_mor      , e_bf_mul    ,
+            e_bf_ncdf      , e_bf_pow      , e_bf_root     , e_bf_round  ,
+            e_bf_roundn    , e_bf_sec      , e_bf_sgn      , e_bf_sin    ,
+            e_bf_sinc      , e_bf_sinh     , e_bf_sqrt     , e_bf_sum    ,
+            e_bf_swap      , e_bf_tan      , e_bf_tanh     , e_bf_trunc  ,
+            e_bf_not_equal , e_bf_inrange  , e_bf_deg2grad , e_bf_deg2rad,
+            e_bf_rad2deg   , e_bf_grad2deg
+         };
+
+         enum settings_control_structs
+         {
+            e_ctrl_unknown = 0,
+            e_ctrl_ifelse,
+            e_ctrl_switch,
+            e_ctrl_for_loop,
+            e_ctrl_while_loop,
+            e_ctrl_repeat_loop,
+            e_ctrl_return
+         };
+
+         enum settings_logic_opr
+         {
+            e_logic_unknown = 0,
+            e_logic_and, e_logic_nand,  e_logic_nor,
+            e_logic_not, e_logic_or,    e_logic_xnor,
+            e_logic_xor, e_logic_scand, e_logic_scor
+         };
+
+         enum settings_arithmetic_opr
+         {
+            e_arith_unknown = 0,
+            e_arith_add, e_arith_sub, e_arith_mul,
+            e_arith_div, e_arith_mod, e_arith_pow
+         };
+
+         enum settings_assignment_opr
+         {
+            e_assign_unknown = 0,
+            e_assign_assign, e_assign_addass, e_assign_subass,
+            e_assign_mulass, e_assign_divass, e_assign_modass
+         };
+
+         enum settings_inequality_opr
+         {
+            e_ineq_unknown = 0,
+            e_ineq_lt,    e_ineq_lte, e_ineq_eq,
+            e_ineq_equal, e_ineq_ne,  e_ineq_nequal,
+            e_ineq_gte,   e_ineq_gt
+         };
+
+         static const std::size_t compile_all_opts = e_replacer          +
+                                                     e_joiner            +
+                                                     e_numeric_check     +
+                                                     e_bracket_check     +
+                                                     e_sequence_check    +
+                                                     e_commutative_check +
+                                                     e_strength_reduction;
+
+         settings_store(const std::size_t compile_options = compile_all_opts)
+         {
+           load_compile_options(compile_options);
+         }
+
+         settings_store& enable_all_base_functions()
+         {
+            disabled_func_set_.clear();
+            return (*this);
+         }
+
+         settings_store& enable_all_control_structures()
+         {
+            disabled_ctrl_set_.clear();
+            return (*this);
+         }
+
+         settings_store& enable_all_logic_ops()
+         {
+            disabled_logic_set_.clear();
+            return (*this);
+         }
+
+         settings_store& enable_all_arithmetic_ops()
+         {
+            disabled_arithmetic_set_.clear();
+            return (*this);
+         }
+
+         settings_store& enable_all_assignment_ops()
+         {
+            disabled_assignment_set_.clear();
+            return (*this);
+         }
+
+         settings_store& enable_all_inequality_ops()
+         {
+            disabled_inequality_set_.clear();
+            return (*this);
+         }
+
+         settings_store& enable_local_vardef()
+         {
+            disable_vardef_ = false;
+            return (*this);
+         }
+
+         settings_store& disable_all_base_functions()
+         {
+            std::copy(details::base_function_list,
+                      details::base_function_list + details::base_function_list_size,
+                      std::insert_iterator<disabled_entity_set_t>
+                        (disabled_func_set_, disabled_func_set_.begin()));
+            return (*this);
+         }
+
+         settings_store& disable_all_control_structures()
+         {
+            std::copy(details::cntrl_struct_list,
+                      details::cntrl_struct_list + details::cntrl_struct_list_size,
+                      std::insert_iterator<disabled_entity_set_t>
+                        (disabled_ctrl_set_, disabled_ctrl_set_.begin()));
+            return (*this);
+         }
+
+         settings_store& disable_all_logic_ops()
+         {
+            std::copy(details::logic_ops_list,
+                      details::logic_ops_list + details::logic_ops_list_size,
+                      std::insert_iterator<disabled_entity_set_t>
+                        (disabled_logic_set_, disabled_logic_set_.begin()));
+            return (*this);
+         }
+
+         settings_store& disable_all_arithmetic_ops()
+         {
+            std::copy(details::arithmetic_ops_list,
+                      details::arithmetic_ops_list + details::arithmetic_ops_list_size,
+                      std::insert_iterator<disabled_entity_set_t>
+                        (disabled_arithmetic_set_, disabled_arithmetic_set_.begin()));
+            return (*this);
+         }
+
+         settings_store& disable_all_assignment_ops()
+         {
+            std::copy(details::assignment_ops_list,
+                      details::assignment_ops_list + details::assignment_ops_list_size,
+                      std::insert_iterator<disabled_entity_set_t>
+                        (disabled_assignment_set_, disabled_assignment_set_.begin()));
+            return (*this);
+         }
+
+         settings_store& disable_all_inequality_ops()
+         {
+            std::copy(details::inequality_ops_list,
+                      details::inequality_ops_list + details::inequality_ops_list_size,
+                      std::insert_iterator<disabled_entity_set_t>
+                        (disabled_inequality_set_, disabled_inequality_set_.begin()));
+            return (*this);
+         }
+
+         settings_store& disable_local_vardef()
+         {
+            disable_vardef_ = true;
+            return (*this);
+         }
+
+         bool replacer_enabled           () const { return enable_replacer_;           }
+         bool commutative_check_enabled  () const { return enable_commutative_check_;  }
+         bool joiner_enabled             () const { return enable_joiner_;             }
+         bool numeric_check_enabled      () const { return enable_numeric_check_;      }
+         bool bracket_check_enabled      () const { return enable_bracket_check_;      }
+         bool sequence_check_enabled     () const { return enable_sequence_check_;     }
+         bool strength_reduction_enabled () const { return enable_strength_reduction_; }
+         bool collect_variables_enabled  () const { return enable_collect_vars_;       }
+         bool collect_functions_enabled  () const { return enable_collect_funcs_;      }
+         bool collect_assignments_enabled() const { return enable_collect_assings_;    }
+         bool vardef_disabled            () const { return disable_vardef_;            }
+         bool rsrvd_sym_usr_disabled     () const { return disable_rsrvd_sym_usr_;     }
+         bool zero_return_disabled       () const { return disable_zero_return_;       }
+
+         bool function_enabled(const std::string& function_name) const
+         {
+            if (disabled_func_set_.empty())
+               return true;
+            else
+               return (disabled_func_set_.end() == disabled_func_set_.find(function_name));
+         }
+
+         bool control_struct_enabled(const std::string& control_struct) const
+         {
+            if (disabled_ctrl_set_.empty())
+               return true;
+            else
+               return (disabled_ctrl_set_.end() == disabled_ctrl_set_.find(control_struct));
+         }
+
+         bool logic_enabled(const std::string& logic_operation) const
+         {
+            if (disabled_logic_set_.empty())
+               return true;
+            else
+               return (disabled_logic_set_.end() == disabled_logic_set_.find(logic_operation));
+         }
+
+         bool arithmetic_enabled(const details::operator_type& arithmetic_operation) const
+         {
+            if (disabled_logic_set_.empty())
+               return true;
+            else
+               return disabled_arithmetic_set_.end() == disabled_arithmetic_set_
+                                                            .find(arith_opr_to_string(arithmetic_operation));
+         }
+
+         bool assignment_enabled(const details::operator_type& assignment) const
+         {
+            if (disabled_assignment_set_.empty())
+               return true;
+            else
+               return disabled_assignment_set_.end() == disabled_assignment_set_
+                                                           .find(assign_opr_to_string(assignment));
+         }
+
+         bool inequality_enabled(const details::operator_type& inequality) const
+         {
+            if (disabled_inequality_set_.empty())
+               return true;
+            else
+               return disabled_inequality_set_.end() == disabled_inequality_set_
+                                                           .find(inequality_opr_to_string(inequality));
+         }
+
+         bool function_disabled(const std::string& function_name) const
+         {
+            if (disabled_func_set_.empty())
+               return false;
+            else
+               return (disabled_func_set_.end() != disabled_func_set_.find(function_name));
+         }
+
+         bool control_struct_disabled(const std::string& control_struct) const
+         {
+            if (disabled_ctrl_set_.empty())
+               return false;
+            else
+               return (disabled_ctrl_set_.end() != disabled_ctrl_set_.find(control_struct));
+         }
+
+         bool logic_disabled(const std::string& logic_operation) const
+         {
+            if (disabled_logic_set_.empty())
+               return false;
+            else
+               return (disabled_logic_set_.end() != disabled_logic_set_.find(logic_operation));
+         }
+
+         bool assignment_disabled(const details::operator_type assignment_operation) const
+         {
+            if (disabled_assignment_set_.empty())
+               return false;
+            else
+               return disabled_assignment_set_.end() != disabled_assignment_set_
+                                                           .find(assign_opr_to_string(assignment_operation));
+         }
+
+         bool logic_disabled(const details::operator_type logic_operation) const
+         {
+            if (disabled_logic_set_.empty())
+               return false;
+            else
+               return disabled_logic_set_.end() != disabled_logic_set_
+                                                           .find(logic_opr_to_string(logic_operation));
+         }
+
+         bool arithmetic_disabled(const details::operator_type arithmetic_operation) const
+         {
+            if (disabled_arithmetic_set_.empty())
+               return false;
+            else
+               return disabled_arithmetic_set_.end() != disabled_arithmetic_set_
+                                                           .find(arith_opr_to_string(arithmetic_operation));
+         }
+
+         bool inequality_disabled(const details::operator_type& inequality) const
+         {
+            if (disabled_inequality_set_.empty())
+               return false;
+            else
+               return disabled_inequality_set_.end() != disabled_inequality_set_
+                                                           .find(inequality_opr_to_string(inequality));
+         }
+
+         settings_store& disable_base_function(settings_base_funcs bf)
+         {
+            if (
+                 (e_bf_unknown != bf) &&
+                 (static_cast<std::size_t>(bf) < (details::base_function_list_size + 1))
+               )
+            {
+               disabled_func_set_.insert(details::base_function_list[bf - 1]);
+            }
+
+            return (*this);
+         }
+
+         settings_store& disable_control_structure(settings_control_structs ctrl_struct)
+         {
+            if (
+                 (e_ctrl_unknown != ctrl_struct) &&
+                 (static_cast<std::size_t>(ctrl_struct) < (details::cntrl_struct_list_size + 1))
+               )
+            {
+               disabled_ctrl_set_.insert(details::cntrl_struct_list[ctrl_struct - 1]);
+            }
+
+            return (*this);
+         }
+
+         settings_store& disable_logic_operation(settings_logic_opr logic)
+         {
+            if (
+                 (e_logic_unknown != logic) &&
+                 (static_cast<std::size_t>(logic) < (details::logic_ops_list_size + 1))
+               )
+            {
+               disabled_logic_set_.insert(details::logic_ops_list[logic - 1]);
+            }
+
+            return (*this);
+         }
+
+         settings_store& disable_arithmetic_operation(settings_arithmetic_opr arithmetic)
+         {
+            if (
+                 (e_arith_unknown != arithmetic) &&
+                 (static_cast<std::size_t>(arithmetic) < (details::arithmetic_ops_list_size + 1))
+               )
+            {
+               disabled_arithmetic_set_.insert(details::arithmetic_ops_list[arithmetic - 1]);
+            }
+
+            return (*this);
+         }
+
+         settings_store& disable_assignment_operation(settings_assignment_opr assignment)
+         {
+            if (
+                 (e_assign_unknown != assignment) &&
+                 (static_cast<std::size_t>(assignment) < (details::assignment_ops_list_size + 1))
+               )
+            {
+               disabled_assignment_set_.insert(details::assignment_ops_list[assignment - 1]);
+            }
+
+            return (*this);
+         }
+
+         settings_store& disable_inequality_operation(settings_inequality_opr inequality)
+         {
+            if (
+                 (e_ineq_unknown != inequality) &&
+                 (static_cast<std::size_t>(inequality) < (details::inequality_ops_list_size + 1))
+               )
+            {
+               disabled_inequality_set_.insert(details::inequality_ops_list[inequality - 1]);
+            }
+
+            return (*this);
+         }
+
+         settings_store& enable_base_function(settings_base_funcs bf)
+         {
+            if (
+                 (e_bf_unknown != bf) &&
+                 (static_cast<std::size_t>(bf) < (details::base_function_list_size + 1))
+               )
+            {
+               const des_itr_t itr = disabled_func_set_.find(details::base_function_list[bf - 1]);
+
+               if (disabled_func_set_.end() != itr)
+               {
+                  disabled_func_set_.erase(itr);
+               }
+            }
+
+            return (*this);
+         }
+
+         settings_store& enable_control_structure(settings_control_structs ctrl_struct)
+         {
+            if (
+                 (e_ctrl_unknown != ctrl_struct) &&
+                 (static_cast<std::size_t>(ctrl_struct) < (details::cntrl_struct_list_size + 1))
+               )
+            {
+               const des_itr_t itr = disabled_ctrl_set_.find(details::cntrl_struct_list[ctrl_struct - 1]);
+
+               if (disabled_ctrl_set_.end() != itr)
+               {
+                  disabled_ctrl_set_.erase(itr);
+               }
+            }
+
+            return (*this);
+         }
+
+         settings_store& enable_logic_operation(settings_logic_opr logic)
+         {
+            if (
+                 (e_logic_unknown != logic) &&
+                 (static_cast<std::size_t>(logic) < (details::logic_ops_list_size + 1))
+               )
+            {
+               const des_itr_t itr = disabled_logic_set_.find(details::logic_ops_list[logic - 1]);
+
+               if (disabled_logic_set_.end() != itr)
+               {
+                  disabled_logic_set_.erase(itr);
+               }
+            }
+
+            return (*this);
+         }
+
+         settings_store& enable_arithmetic_operation(settings_arithmetic_opr arithmetic)
+         {
+            if (
+                 (e_arith_unknown != arithmetic) &&
+                 (static_cast<std::size_t>(arithmetic) < (details::arithmetic_ops_list_size + 1))
+               )
+            {
+               const des_itr_t itr = disabled_arithmetic_set_.find(details::arithmetic_ops_list[arithmetic - 1]);
+
+               if (disabled_arithmetic_set_.end() != itr)
+               {
+                  disabled_arithmetic_set_.erase(itr);
+               }
+            }
+
+            return (*this);
+         }
+
+         settings_store& enable_assignment_operation(settings_assignment_opr assignment)
+         {
+            if (
+                 (e_assign_unknown != assignment) &&
+                 (static_cast<std::size_t>(assignment) < (details::assignment_ops_list_size + 1))
+               )
+            {
+               const des_itr_t itr = disabled_assignment_set_.find(details::assignment_ops_list[assignment - 1]);
+
+               if (disabled_assignment_set_.end() != itr)
+               {
+                  disabled_assignment_set_.erase(itr);
+               }
+            }
+
+            return (*this);
+         }
+
+         settings_store& enable_inequality_operation(settings_inequality_opr inequality)
+         {
+            if (
+                 (e_ineq_unknown != inequality) &&
+                 (static_cast<std::size_t>(inequality) < (details::inequality_ops_list_size + 1))
+               )
+            {
+               const des_itr_t itr = disabled_inequality_set_.find(details::inequality_ops_list[inequality - 1]);
+
+               if (disabled_inequality_set_.end() != itr)
+               {
+                  disabled_inequality_set_.erase(itr);
+               }
+            }
+
+            return (*this);
+         }
+
+      private:
+
+         void load_compile_options(const std::size_t compile_options)
+         {
+            enable_replacer_           = (compile_options & e_replacer            ) == e_replacer;
+            enable_joiner_             = (compile_options & e_joiner              ) == e_joiner;
+            enable_numeric_check_      = (compile_options & e_numeric_check       ) == e_numeric_check;
+            enable_bracket_check_      = (compile_options & e_bracket_check       ) == e_bracket_check;
+            enable_sequence_check_     = (compile_options & e_sequence_check      ) == e_sequence_check;
+            enable_commutative_check_  = (compile_options & e_commutative_check   ) == e_commutative_check;
+            enable_strength_reduction_ = (compile_options & e_strength_reduction  ) == e_strength_reduction;
+            enable_collect_vars_       = (compile_options & e_collect_vars        ) == e_collect_vars;
+            enable_collect_funcs_      = (compile_options & e_collect_funcs       ) == e_collect_funcs;
+            enable_collect_assings_    = (compile_options & e_collect_assings     ) == e_collect_assings;
+            disable_vardef_            = (compile_options & e_disable_vardef      ) == e_disable_vardef;
+            disable_rsrvd_sym_usr_     = (compile_options & e_disable_usr_on_rsrvd) == e_disable_usr_on_rsrvd;
+            disable_zero_return_       = (compile_options & e_disable_zero_return ) == e_disable_zero_return;
+         }
+
+         std::string assign_opr_to_string(details::operator_type opr) const
+         {
+            switch (opr)
+            {
+               case details::e_assign : return ":=";
+               case details::e_addass : return "+=";
+               case details::e_subass : return "-=";
+               case details::e_mulass : return "*=";
+               case details::e_divass : return "/=";
+               case details::e_modass : return "%=";
+               default                : return   "";
+            }
+         }
+
+         std::string arith_opr_to_string(details::operator_type opr) const
+         {
+            switch (opr)
+            {
+               case details::e_add : return "+";
+               case details::e_sub : return "-";
+               case details::e_mul : return "*";
+               case details::e_div : return "/";
+               case details::e_mod : return "%";
+               default             : return  "";
+            }
+         }
+
+         std::string inequality_opr_to_string(details::operator_type opr) const
+         {
+            switch (opr)
+            {
+               case details::e_lt    : return  "<";
+               case details::e_lte   : return "<=";
+               case details::e_eq    : return "==";
+               case details::e_equal : return  "=";
+               case details::e_ne    : return "!=";
+               case details::e_nequal: return "<>";
+               case details::e_gte   : return ">=";
+               case details::e_gt    : return  ">";
+               default               : return   "";
+            }
+         }
+
+         std::string logic_opr_to_string(details::operator_type opr) const
+         {
+            switch (opr)
+            {
+               case details::e_and  : return "and" ;
+               case details::e_or   : return "or"  ;
+               case details::e_xor  : return "xor" ;
+               case details::e_nand : return "nand";
+               case details::e_nor  : return "nor" ;
+               case details::e_xnor : return "xnor";
+               case details::e_notl : return "not" ;
+               default              : return ""    ;
+            }
+         }
+
+         bool enable_replacer_;
+         bool enable_joiner_;
+         bool enable_numeric_check_;
+         bool enable_bracket_check_;
+         bool enable_sequence_check_;
+         bool enable_commutative_check_;
+         bool enable_strength_reduction_;
+         bool enable_collect_vars_;
+         bool enable_collect_funcs_;
+         bool enable_collect_assings_;
+         bool disable_vardef_;
+         bool disable_rsrvd_sym_usr_;
+         bool disable_zero_return_;
+
+         disabled_entity_set_t disabled_func_set_ ;
+         disabled_entity_set_t disabled_ctrl_set_ ;
+         disabled_entity_set_t disabled_logic_set_;
+         disabled_entity_set_t disabled_arithmetic_set_;
+         disabled_entity_set_t disabled_assignment_set_;
+         disabled_entity_set_t disabled_inequality_set_;
+
+         friend class parser<T>;
+      };
+
+      typedef settings_store settings_t;
+
+      parser(const settings_t& settings = settings_t())
+      : settings_(settings),
+        resolve_unknown_symbol_(false),
+        results_context_(0),
+        unknown_symbol_resolver_(reinterpret_cast<unknown_symbol_resolver*>(0)),
+        #ifdef _MSC_VER
+        #pragma warning(push)
+        #pragma warning (disable:4355)
+        #endif
+        sem_(*this),
+        #ifdef _MSC_VER
+        #pragma warning(pop)
+        #endif
+        operator_joiner_2_(2),
+        operator_joiner_3_(3)
+      {
+         init_precompilation();
+
+         load_operations_map           (base_ops_map_     );
+         load_unary_operations_map     (unary_op_map_     );
+         load_binary_operations_map    (binary_op_map_    );
+         load_inv_binary_operations_map(inv_binary_op_map_);
+         load_sf3_map                  (sf3_map_          );
+         load_sf4_map                  (sf4_map_          );
+
+         expression_generator_.init_synthesize_map();
+         expression_generator_.set_parser(*this);
+         expression_generator_.set_uom(unary_op_map_);
+         expression_generator_.set_bom(binary_op_map_);
+         expression_generator_.set_ibom(inv_binary_op_map_);
+         expression_generator_.set_sf3m(sf3_map_);
+         expression_generator_.set_sf4m(sf4_map_);
+         expression_generator_.set_strength_reduction_state(settings_.strength_reduction_enabled());
+      }
+
+     ~parser()
+      {}
+
+      inline void init_precompilation()
+      {
+         if (settings_.collect_variables_enabled())
+            dec_.collect_variables() = true;
+
+         if (settings_.collect_functions_enabled())
+            dec_.collect_functions() = true;
+
+         if (settings_.collect_assignments_enabled())
+            dec_.collect_assignments() = true;
+
+         if (settings_.replacer_enabled())
+         {
+            symbol_replacer_.clear();
+            symbol_replacer_.add_replace("true" , "1", lexer::token::e_number);
+            symbol_replacer_.add_replace("false", "0", lexer::token::e_number);
+            helper_assembly_.token_modifier_list.clear();
+            helper_assembly_.register_modifier(&symbol_replacer_);
+         }
+
+         if (settings_.commutative_check_enabled())
+         {
+            for (std::size_t i = 0; i < details::reserved_words_size; ++i)
+            {
+               commutative_inserter_.ignore_symbol(details::reserved_words[i]);
+            }
+
+            helper_assembly_.token_inserter_list.clear();
+            helper_assembly_.register_inserter(&commutative_inserter_);
+         }
+
+         if (settings_.joiner_enabled())
+         {
+            helper_assembly_.token_joiner_list.clear();
+            helper_assembly_.register_joiner(&operator_joiner_2_);
+            helper_assembly_.register_joiner(&operator_joiner_3_);
+         }
+
+         if (
+              settings_.numeric_check_enabled () ||
+              settings_.bracket_check_enabled () ||
+              settings_.sequence_check_enabled()
+            )
+         {
+            helper_assembly_.token_scanner_list.clear();
+
+            if (settings_.numeric_check_enabled())
+            {
+               helper_assembly_.register_scanner(&numeric_checker_);
+            }
+
+            if (settings_.bracket_check_enabled())
+            {
+               helper_assembly_.register_scanner(&bracket_checker_);
+            }
+
+            if (settings_.sequence_check_enabled())
+            {
+               helper_assembly_.register_scanner(&sequence_validator_      );
+               helper_assembly_.register_scanner(&sequence_validator_3tkns_);
+            }
+         }
+      }
+
+      inline bool compile(const std::string& expression_string, expression<T>& expr)
+      {
+         state_          .reset();
+         error_list_     .clear();
+         brkcnt_list_    .clear();
+         synthesis_error_.clear();
+         sem_            .cleanup();
+
+         return_cleanup();
+
+         expression_generator_.set_allocator(node_allocator_);
+
+         if (expression_string.empty())
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          "ERR000 - Empty expression!",
+                          exprtk_error_location));
+
+            return false;
+         }
+
+         if (!init(expression_string))
+         {
+            process_lexer_errors();
+            return false;
+         }
+
+         if (lexer().empty())
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          "ERR001 - Empty expression!",
+                          exprtk_error_location));
+
+            return false;
+         }
+
+         if (!run_assemblies())
+         {
+            return false;
+         }
+
+         symtab_store_.symtab_list_ = expr.get_symbol_table_list();
+         dec_.clear();
+
+         lexer().begin();
+
+         next_token();
+
+         expression_node_ptr e = parse_corpus();
+
+         if ((0 != e) && (token_t::e_eof == current_token().type))
+         {
+            bool* retinvk_ptr = 0;
+
+            if (state_.return_stmt_present)
+            {
+               dec_.return_present_ = true;
+
+               e = expression_generator_
+                     .return_envelope(e, results_context_, retinvk_ptr);
+            }
+
+            expr.set_expression(e);
+            expr.set_retinvk(retinvk_ptr);
+
+            register_local_vars(expr);
+            register_return_results(expr);
+
+            return !(!expr);
+         }
+         else
+         {
+            if (error_list_.empty())
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR002 - Invalid expression encountered",
+                             exprtk_error_location));
+            }
+
+            if ((0 != e) && branch_deletable(e))
+            {
+               destroy_node(e);
+            }
+
+            dec_.clear    ();
+            sem_.cleanup  ();
+            return_cleanup();
+
+            return false;
+         }
+      }
+
+      inline expression_t compile(const std::string& expression_string, symbol_table_t& symtab)
+      {
+         expression_t expr;
+
+         expr.register_symbol_table(symtab);
+
+         compile(expression_string,expr);
+
+         return expr;
+      }
+
+      void process_lexer_errors()
+      {
+         for (std::size_t i = 0; i < lexer().size(); ++i)
+         {
+            if (lexer()[i].is_error())
+            {
+               std::string diagnostic = "ERR003 - ";
+
+               switch (lexer()[i].type)
+               {
+                  case lexer::token::e_error      : diagnostic += "General token error";
+                                                    break;
+
+                  case lexer::token::e_err_symbol : diagnostic += "Symbol error";
+                                                    break;
+
+                  case lexer::token::e_err_number : diagnostic += "Invalid numeric token";
+                                                    break;
+
+                  case lexer::token::e_err_string : diagnostic += "Invalid string token";
+                                                    break;
+
+                  case lexer::token::e_err_sfunc  : diagnostic += "Invalid special function token";
+                                                    break;
+
+                  default                         : diagnostic += "Unknown compiler error";
+               }
+
+               set_error(
+                  make_error(parser_error::e_lexer,
+                             lexer()[i],
+                             diagnostic + ": " + lexer()[i].value,
+                             exprtk_error_location));
+            }
+         }
+      }
+
+      inline bool run_assemblies()
+      {
+         if (settings_.commutative_check_enabled())
+         {
+            helper_assembly_.run_inserters(lexer());
+         }
+
+         if (settings_.joiner_enabled())
+         {
+            helper_assembly_.run_joiners(lexer());
+         }
+
+         if (settings_.replacer_enabled())
+         {
+            helper_assembly_.run_modifiers(lexer());
+         }
+
+         if (
+              settings_.numeric_check_enabled () ||
+              settings_.bracket_check_enabled () ||
+              settings_.sequence_check_enabled()
+            )
+         {
+            if (!helper_assembly_.run_scanners(lexer()))
+            {
+               if (helper_assembly_.error_token_scanner)
+               {
+                  lexer::helper::bracket_checker*            bracket_checker_ptr     = 0;
+                  lexer::helper::numeric_checker*            numeric_checker_ptr     = 0;
+                  lexer::helper::sequence_validator*         sequence_validator_ptr  = 0;
+                  lexer::helper::sequence_validator_3tokens* sequence_validator3_ptr = 0;
+
+                  if (0 != (bracket_checker_ptr = dynamic_cast<lexer::helper::bracket_checker*>(helper_assembly_.error_token_scanner)))
+                  {
+                     set_error(
+                        make_error(parser_error::e_token,
+                                   bracket_checker_ptr->error_token(),
+                                   "ERR004 - Mismatched brackets: '" + bracket_checker_ptr->error_token().value + "'",
+                                   exprtk_error_location));
+                  }
+                  else if (0 != (numeric_checker_ptr = dynamic_cast<lexer::helper::numeric_checker*>(helper_assembly_.error_token_scanner)))
+                  {
+                     for (std::size_t i = 0; i < numeric_checker_ptr->error_count(); ++i)
+                     {
+                        lexer::token error_token = lexer()[numeric_checker_ptr->error_index(i)];
+
+                        set_error(
+                           make_error(parser_error::e_token,
+                                      error_token,
+                                      "ERR005 - Invalid numeric token: '" + error_token.value + "'",
+                                      exprtk_error_location));
+                     }
+
+                     if (numeric_checker_ptr->error_count())
+                     {
+                        numeric_checker_ptr->clear_errors();
+                     }
+                  }
+                  else if (0 != (sequence_validator_ptr = dynamic_cast<lexer::helper::sequence_validator*>(helper_assembly_.error_token_scanner)))
+                  {
+                     for (std::size_t i = 0; i < sequence_validator_ptr->error_count(); ++i)
+                     {
+                        std::pair<lexer::token,lexer::token> error_token = sequence_validator_ptr->error(i);
+
+                        set_error(
+                           make_error(parser_error::e_token,
+                                      error_token.first,
+                                      "ERR006 - Invalid token sequence: '" +
+                                      error_token.first.value  + "' and '" +
+                                      error_token.second.value + "'",
+                                      exprtk_error_location));
+                     }
+
+                     if (sequence_validator_ptr->error_count())
+                     {
+                        sequence_validator_ptr->clear_errors();
+                     }
+                  }
+                  else if (0 != (sequence_validator3_ptr = dynamic_cast<lexer::helper::sequence_validator_3tokens*>(helper_assembly_.error_token_scanner)))
+                  {
+                     for (std::size_t i = 0; i < sequence_validator3_ptr->error_count(); ++i)
+                     {
+                        std::pair<lexer::token,lexer::token> error_token = sequence_validator3_ptr->error(i);
+
+                        set_error(
+                           make_error(parser_error::e_token,
+                                      error_token.first,
+                                      "ERR007 - Invalid token sequence: '" +
+                                      error_token.first.value  + "' and '" +
+                                      error_token.second.value + "'",
+                                      exprtk_error_location));
+                     }
+
+                     if (sequence_validator3_ptr->error_count())
+                     {
+                        sequence_validator3_ptr->clear_errors();
+                     }
+                  }
+               }
+
+               return false;
+            }
+         }
+
+         return true;
+      }
+
+      inline settings_store& settings()
+      {
+         return settings_;
+      }
+
+      inline parser_error::type get_error(const std::size_t& index) const
+      {
+         if (index < error_list_.size())
+            return error_list_[index];
+         else
+            throw std::invalid_argument("parser::get_error() - Invalid error index specificed");
+      }
+
+      inline std::string error() const
+      {
+         if (!error_list_.empty())
+         {
+            return error_list_[0].diagnostic;
+         }
+         else
+            return std::string("No Error");
+      }
+
+      inline std::size_t error_count() const
+      {
+         return error_list_.size();
+      }
+
+      inline dependent_entity_collector& dec()
+      {
+         return dec_;
+      }
+
+      inline bool replace_symbol(const std::string& old_symbol, const std::string& new_symbol)
+      {
+         if (!settings_.replacer_enabled())
+            return false;
+         else if (details::is_reserved_word(old_symbol))
+            return false;
+         else
+            return symbol_replacer_.add_replace(old_symbol,new_symbol,lexer::token::e_symbol);
+      }
+
+      inline bool remove_replace_symbol(const std::string& symbol)
+      {
+         if (!settings_.replacer_enabled())
+            return false;
+         else if (details::is_reserved_word(symbol))
+            return false;
+         else
+            return symbol_replacer_.remove(symbol);
+      }
+
+      inline void enable_unknown_symbol_resolver(unknown_symbol_resolver* usr = reinterpret_cast<unknown_symbol_resolver*>(0))
+      {
+         resolve_unknown_symbol_ = true;
+
+         if (usr)
+            unknown_symbol_resolver_ = usr;
+         else
+            unknown_symbol_resolver_ = &default_usr_;
+      }
+
+      inline void enable_unknown_symbol_resolver(unknown_symbol_resolver& usr)
+      {
+         enable_unknown_symbol_resolver(&usr);
+      }
+
+      inline void disable_unknown_symbol_resolver()
+      {
+         resolve_unknown_symbol_  = false;
+         unknown_symbol_resolver_ = &default_usr_;
+      }
+
+   private:
+
+      inline bool valid_base_operation(const std::string& symbol) const
+      {
+         const std::size_t length = symbol.size();
+
+         if (
+              (length < 3) || // Shortest base op symbol length
+              (length > 9)    // Longest base op symbol length
+            )
+            return false;
+         else
+            return settings_.function_enabled(symbol) &&
+                   (base_ops_map_.end() != base_ops_map_.find(symbol));
+      }
+
+      inline bool valid_vararg_operation(const std::string& symbol) const
+      {
+         static const std::string s_sum     = "sum" ;
+         static const std::string s_mul     = "mul" ;
+         static const std::string s_avg     = "avg" ;
+         static const std::string s_min     = "min" ;
+         static const std::string s_max     = "max" ;
+         static const std::string s_mand    = "mand";
+         static const std::string s_mor     = "mor" ;
+         static const std::string s_multi   = "~"   ;
+         static const std::string s_mswitch = "[*]" ;
+
+         return
+               (
+                  details::imatch(symbol,s_sum    ) ||
+                  details::imatch(symbol,s_mul    ) ||
+                  details::imatch(symbol,s_avg    ) ||
+                  details::imatch(symbol,s_min    ) ||
+                  details::imatch(symbol,s_max    ) ||
+                  details::imatch(symbol,s_mand   ) ||
+                  details::imatch(symbol,s_mor    ) ||
+                  details::imatch(symbol,s_multi  ) ||
+                  details::imatch(symbol,s_mswitch)
+               ) &&
+               settings_.function_enabled(symbol);
+      }
+
+      bool is_invalid_logic_operation(const details::operator_type operation) const
+      {
+         return settings_.logic_disabled(operation);
+      }
+
+      bool is_invalid_arithmetic_operation(const details::operator_type operation) const
+      {
+         return settings_.arithmetic_disabled(operation);
+      }
+
+      bool is_invalid_assignment_operation(const details::operator_type operation) const
+      {
+         return settings_.assignment_disabled(operation);
+      }
+
+      bool is_invalid_inequality_operation(const details::operator_type operation) const
+      {
+         return settings_.inequality_disabled(operation);
+      }
+
+      #ifdef exprtk_enable_debugging
+      inline void next_token()
+      {
+         const std::string ct_str = current_token().value;
+         parser_helper::next_token();
+         const std::string depth(2 * state_.scope_depth,' ');
+         exprtk_debug(("%s"
+                       "prev[%s] --> curr[%s]\n",
+                       depth.c_str(),
+                       ct_str.c_str(),
+                       current_token().value.c_str()));
+      }
+      #endif
+
+      inline expression_node_ptr parse_corpus()
+      {
+         std::vector<expression_node_ptr> arg_list;
+         std::vector<bool> side_effect_list;
+
+         scoped_vec_delete<expression_node_t> sdd((*this),arg_list);
+
+         lexer::token begin_token;
+         lexer::token   end_token;
+
+         for ( ; ; )
+         {
+            state_.side_effect_present = false;
+
+            begin_token = current_token();
+
+            expression_node_ptr arg = parse_expression();
+
+            if (0 == arg)
+            {
+               if (error_list_.empty())
+               {
+                  set_error(
+                     make_error(parser_error::e_syntax,
+                                current_token(),
+                                "ERR008 - Invalid expression encountered",
+                                exprtk_error_location));
+               }
+
+               return error_node();
+            }
+            else
+            {
+               arg_list.push_back(arg);
+
+               side_effect_list.push_back(state_.side_effect_present);
+
+               end_token = current_token();
+
+               const std::string sub_expr = construct_subexpr(begin_token, end_token);
+
+               exprtk_debug(("parse_corpus(%02d) Subexpr: %s\n",
+                             static_cast<int>(arg_list.size() - 1),
+                             sub_expr.c_str()));
+
+               exprtk_debug(("parse_corpus(%02d) - Side effect present: %s\n",
+                             static_cast<int>(arg_list.size() - 1),
+                             state_.side_effect_present ? "true" : "false"));
+
+               exprtk_debug(("-------------------------------------------------\n"));
+            }
+
+            if (lexer().finished())
+               break;
+            else if (token_is(token_t::e_eof,prsrhlpr_t::e_hold))
+            {
+               if (lexer().finished())
+                  break;
+               else
+                  next_token();
+            }
+         }
+
+         if (
+              !arg_list.empty() &&
+              is_return_node(arg_list.back())
+            )
+         {
+            dec_.final_stmt_return_ = true;
+         }
+
+         const expression_node_ptr result = simplify(arg_list,side_effect_list);
+
+         sdd.delete_ptr = (0 == result);
+
+         return result;
+      }
+
+      std::string construct_subexpr(lexer::token& begin_token, lexer::token& end_token)
+      {
+         std::string result = lexer().substr(begin_token.position,end_token.position);
+
+         for (std::size_t i = 0; i < result.size(); ++i)
+         {
+            if (details::is_whitespace(result[i])) result[i] = ' ';
+         }
+
+         return result;
+      }
+
+      static const precedence_level default_precedence = e_level00;
+
+      struct state_t
+      {
+         inline void set(const precedence_level& l,
+                         const precedence_level& r,
+                         const details::operator_type& o)
+         {
+            left  = l;
+            right = r;
+            operation = o;
+         }
+
+         inline void reset()
+         {
+            left      = e_level00;
+            right     = e_level00;
+            operation = details::e_default;
+         }
+
+         precedence_level left;
+         precedence_level right;
+         details::operator_type operation;
+      };
+
+      inline expression_node_ptr parse_expression(precedence_level precedence = e_level00)
+      {
+         expression_node_ptr expression = parse_branch(precedence);
+
+         if (0 == expression)
+         {
+            return error_node();
+         }
+
+         bool break_loop = false;
+
+         state_t current_state;
+
+         for ( ; ; )
+         {
+            current_state.reset();
+
+            switch (current_token().type)
+            {
+               case token_t::e_assign : current_state.set(e_level00,e_level00, details::e_assign); break;
+               case token_t::e_addass : current_state.set(e_level00,e_level00, details::e_addass); break;
+               case token_t::e_subass : current_state.set(e_level00,e_level00, details::e_subass); break;
+               case token_t::e_mulass : current_state.set(e_level00,e_level00, details::e_mulass); break;
+               case token_t::e_divass : current_state.set(e_level00,e_level00, details::e_divass); break;
+               case token_t::e_modass : current_state.set(e_level00,e_level00, details::e_modass); break;
+               case token_t::e_swap   : current_state.set(e_level00,e_level00, details::e_swap  ); break;
+               case token_t::e_lt     : current_state.set(e_level05,e_level06, details::    e_lt); break;
+               case token_t::e_lte    : current_state.set(e_level05,e_level06, details::   e_lte); break;
+               case token_t::e_eq     : current_state.set(e_level05,e_level06, details::    e_eq); break;
+               case token_t::e_ne     : current_state.set(e_level05,e_level06, details::    e_ne); break;
+               case token_t::e_gte    : current_state.set(e_level05,e_level06, details::   e_gte); break;
+               case token_t::e_gt     : current_state.set(e_level05,e_level06, details::    e_gt); break;
+               case token_t::e_add    : current_state.set(e_level07,e_level08, details::   e_add); break;
+               case token_t::e_sub    : current_state.set(e_level07,e_level08, details::   e_sub); break;
+               case token_t::e_div    : current_state.set(e_level10,e_level11, details::   e_div); break;
+               case token_t::e_mul    : current_state.set(e_level10,e_level11, details::   e_mul); break;
+               case token_t::e_mod    : current_state.set(e_level10,e_level11, details::   e_mod); break;
+               case token_t::e_pow    : current_state.set(e_level12,e_level12, details::   e_pow); break;
+               default                : if (token_t::e_symbol == current_token().type)
+                                        {
+                                           static const std::string s_and   =   "and";
+                                           static const std::string s_nand  =  "nand";
+                                           static const std::string s_or    =    "or";
+                                           static const std::string s_nor   =   "nor";
+                                           static const std::string s_xor   =   "xor";
+                                           static const std::string s_xnor  =  "xnor";
+                                           static const std::string s_in    =    "in";
+                                           static const std::string s_like  =  "like";
+                                           static const std::string s_ilike = "ilike";
+                                           static const std::string s_and1  =     "&";
+                                           static const std::string s_or1   =     "|";
+                                           static const std::string s_not   =   "not";
+
+                                           if (details::imatch(current_token().value,s_and))
+                                           {
+                                              current_state.set(e_level03, e_level04, details::e_and);
+                                              break;
+                                           }
+                                           else if (details::imatch(current_token().value,s_and1))
+                                           {
+                                              #ifndef exprtk_disable_sc_andor
+                                              current_state.set(e_level03, e_level04, details::e_scand);
+                                              #else
+                                              current_state.set(e_level03, e_level04, details::e_and);
+                                              #endif
+                                              break;
+                                           }
+                                           else if (details::imatch(current_token().value,s_nand))
+                                           {
+                                              current_state.set(e_level03, e_level04, details::e_nand);
+                                              break;
+                                           }
+                                           else if (details::imatch(current_token().value,s_or))
+                                           {
+                                              current_state.set(e_level01, e_level02, details::e_or);
+                                              break;
+                                           }
+                                           else if (details::imatch(current_token().value,s_or1))
+                                           {
+                                              #ifndef exprtk_disable_sc_andor
+                                              current_state.set(e_level01, e_level02, details::e_scor);
+                                              #else
+                                              current_state.set(e_level01, e_level02, details::e_or);
+                                              #endif
+                                              break;
+                                           }
+                                           else if (details::imatch(current_token().value,s_nor))
+                                           {
+                                              current_state.set(e_level01, e_level02, details::e_nor);
+                                              break;
+                                           }
+                                           else if (details::imatch(current_token().value,s_xor))
+                                           {
+                                              current_state.set(e_level01, e_level02, details::e_xor);
+                                              break;
+                                           }
+                                           else if (details::imatch(current_token().value,s_xnor))
+                                           {
+                                              current_state.set(e_level01, e_level02, details::e_xnor);
+                                              break;
+                                           }
+                                           else if (details::imatch(current_token().value,s_in))
+                                           {
+                                              current_state.set(e_level04, e_level04, details::e_in);
+                                              break;
+                                           }
+                                           else if (details::imatch(current_token().value,s_like))
+                                           {
+                                              current_state.set(e_level04, e_level04, details::e_like);
+                                              break;
+                                           }
+                                           else if (details::imatch(current_token().value,s_ilike))
+                                           {
+                                              current_state.set(e_level04, e_level04, details::e_ilike);
+                                              break;
+                                           }
+                                           else if (details::imatch(current_token().value,s_not))
+                                           {
+                                              break;
+                                           }
+                                        }
+
+                                        break_loop = true;
+            }
+
+            if (break_loop)
+            {
+               parse_pending_string_rangesize(expression);
+               break;
+            }
+            else if (current_state.left < precedence)
+               break;
+
+            const lexer::token prev_token = current_token();
+
+            next_token();
+
+            expression_node_ptr right_branch   = error_node();
+            expression_node_ptr new_expression = error_node();
+
+            if (is_invalid_logic_operation(current_state.operation))
+            {
+               free_node(node_allocator_,expression);
+
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             prev_token,
+                             "ERR009 - Invalid or disabled logic operation '" + details::to_str(current_state.operation) + "'",
+                             exprtk_error_location));
+
+               return error_node();
+            }
+            else if (is_invalid_arithmetic_operation(current_state.operation))
+            {
+               free_node(node_allocator_,expression);
+
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             prev_token,
+                             "ERR010 - Invalid or disabled arithmetic operation '" + details::to_str(current_state.operation) + "'",
+                             exprtk_error_location));
+
+               return error_node();
+            }
+            else if (is_invalid_inequality_operation(current_state.operation))
+            {
+               free_node(node_allocator_,expression);
+
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             prev_token,
+                             "ERR011 - Invalid inequality operation '" + details::to_str(current_state.operation) + "'",
+                             exprtk_error_location));
+
+               return error_node();
+            }
+            else if (is_invalid_assignment_operation(current_state.operation))
+            {
+               free_node(node_allocator_,expression);
+
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             prev_token,
+                             "ERR012 - Invalid or disabled assignment operation '" + details::to_str(current_state.operation) + "'",
+                             exprtk_error_location));
+
+               return error_node();
+            }
+
+            if (0 != (right_branch = parse_expression(current_state.right)))
+            {
+               if (
+                    details::is_return_node(  expression) ||
+                    details::is_return_node(right_branch)
+                  )
+               {
+                  free_node(node_allocator_,   expression);
+                  free_node(node_allocator_, right_branch);
+
+                  set_error(
+                     make_error(parser_error::e_syntax,
+                                prev_token,
+                                "ERR013 - Return statements cannot be part of sub-expressions",
+                                exprtk_error_location));
+
+                  return error_node();
+               }
+
+               new_expression = expression_generator_
+                                  (
+                                    current_state.operation,
+                                    expression,
+                                    right_branch
+                                  );
+            }
+
+            if (0 == new_expression)
+            {
+               if (error_list_.empty())
+               {
+                  set_error(
+                     make_error(parser_error::e_syntax,
+                                prev_token,
+                                !synthesis_error_.empty() ?
+                                synthesis_error_ :
+                                "ERR014 - General parsing error at token: '" + prev_token.value + "'",
+                                exprtk_error_location));
+               }
+
+               free_node(node_allocator_,   expression);
+               free_node(node_allocator_, right_branch);
+
+               return error_node();
+            }
+            else
+            {
+               if (
+                    token_is(token_t::e_ternary,prsrhlpr_t::e_hold) &&
+                    (precedence == e_level00)
+                  )
+               {
+                  expression = parse_ternary_conditional_statement(new_expression);
+               }
+               else
+                  expression = new_expression;
+
+               parse_pending_string_rangesize(expression);
+            }
+         }
+
+         return expression;
+      }
+
+      bool simplify_unary_negation_branch(expression_node_ptr& node)
+      {
+         {
+            typedef details::unary_branch_node<T,details::neg_op<T> > ubn_t;
+            ubn_t* n = dynamic_cast<ubn_t*>(node);
+
+            if (n)
+            {
+               expression_node_ptr un_r = n->branch(0);
+               n->release();
+               free_node(node_allocator_,node);
+               node = un_r;
+
+               return true;
+            }
+         }
+
+         {
+            typedef details::unary_variable_node<T,details::neg_op<T> > uvn_t;
+
+            uvn_t* n = dynamic_cast<uvn_t*>(node);
+
+            if (n)
+            {
+               const T& v = n->v();
+               expression_node_ptr return_node = error_node();
+
+               if (
+                    (0 != (return_node = symtab_store_.get_variable(v))) ||
+                    (0 != (return_node = sem_         .get_variable(v)))
+                  )
+               {
+                  free_node(node_allocator_,node);
+                  node = return_node;
+
+                  return true;
+               }
+               else
+               {
+                  set_error(
+                     make_error(parser_error::e_syntax,
+                                current_token(),
+                                "ERR015 - Failed to find variable node in symbol table",
+                                exprtk_error_location));
+
+                  free_node(node_allocator_,node);
+
+                  return false;
+               }
+            }
+         }
+
+         return false;
+      }
+
+      static inline expression_node_ptr error_node()
+      {
+         return reinterpret_cast<expression_node_ptr>(0);
+      }
+
+      template <typename Type, std::size_t N>
+      struct scoped_delete
+      {
+         typedef Type* ptr_t;
+
+         scoped_delete(parser<T>& pr, ptr_t& p)
+         : delete_ptr(true),
+           parser_(pr),
+           p_(&p)
+         {}
+
+         scoped_delete(parser<T>& pr, ptr_t (&p)[N])
+         : delete_ptr(true),
+           parser_(pr),
+           p_(&p[0])
+         {}
+
+        ~scoped_delete()
+         {
+            if (delete_ptr)
+            {
+               for (std::size_t i = 0; i < N; ++i)
+               {
+                  free_node(parser_.node_allocator_,p_[i]);
+               }
+            }
+         }
+
+         bool delete_ptr;
+         parser<T>& parser_;
+         ptr_t* p_;
+
+      private:
+
+         scoped_delete<Type,N>& operator=(const scoped_delete<Type,N>&);
+      };
+
+      template <typename Type>
+      struct scoped_deq_delete
+      {
+         typedef Type* ptr_t;
+
+         scoped_deq_delete(parser<T>& pr, std::deque<ptr_t>& deq)
+         : delete_ptr(true),
+           parser_(pr),
+           deq_(deq)
+         {}
+
+        ~scoped_deq_delete()
+         {
+            if (delete_ptr && !deq_.empty())
+            {
+               for (std::size_t i = 0; i < deq_.size(); ++i)
+               {
+                  free_node(parser_.node_allocator_,deq_[i]);
+               }
+
+               deq_.clear();
+            }
+         }
+
+         bool delete_ptr;
+         parser<T>& parser_;
+         std::deque<ptr_t>& deq_;
+
+      private:
+
+         scoped_deq_delete<Type>& operator=(const scoped_deq_delete<Type>&);
+      };
+
+      template <typename Type>
+      struct scoped_vec_delete
+      {
+         typedef Type* ptr_t;
+
+         scoped_vec_delete(parser<T>& pr, std::vector<ptr_t>& vec)
+         : delete_ptr(true),
+           parser_(pr),
+           vec_(vec)
+         {}
+
+        ~scoped_vec_delete()
+         {
+            if (delete_ptr && !vec_.empty())
+            {
+               for (std::size_t i = 0; i < vec_.size(); ++i)
+               {
+                  free_node(parser_.node_allocator_,vec_[i]);
+               }
+
+               vec_.clear();
+            }
+         }
+
+         bool delete_ptr;
+         parser<T>& parser_;
+         std::vector<ptr_t>& vec_;
+
+      private:
+
+         scoped_vec_delete<Type>& operator=(const scoped_vec_delete<Type>&);
+      };
+
+      struct scoped_bool_negator
+      {
+         explicit scoped_bool_negator(bool& bb)
+         : b(bb)
+         { b = !b; }
+
+        ~scoped_bool_negator()
+         { b = !b; }
+
+         bool& b;
+      };
+
+      struct scoped_bool_or_restorer
+      {
+         explicit scoped_bool_or_restorer(bool& bb)
+         : b(bb),
+           original_value_(bb)
+         {}
+
+        ~scoped_bool_or_restorer()
+         {
+            b = b || original_value_;
+         }
+
+         bool& b;
+         bool original_value_;
+      };
+
+      inline expression_node_ptr parse_function_invocation(ifunction<T>* function, const std::string& function_name)
+      {
+         expression_node_ptr func_node = reinterpret_cast<expression_node_ptr>(0);
+
+         switch (function->param_count)
+         {
+            case  0 : func_node = parse_function_call_0  (function,function_name); break;
+            case  1 : func_node = parse_function_call< 1>(function,function_name); break;
+            case  2 : func_node = parse_function_call< 2>(function,function_name); break;
+            case  3 : func_node = parse_function_call< 3>(function,function_name); break;
+            case  4 : func_node = parse_function_call< 4>(function,function_name); break;
+            case  5 : func_node = parse_function_call< 5>(function,function_name); break;
+            case  6 : func_node = parse_function_call< 6>(function,function_name); break;
+            case  7 : func_node = parse_function_call< 7>(function,function_name); break;
+            case  8 : func_node = parse_function_call< 8>(function,function_name); break;
+            case  9 : func_node = parse_function_call< 9>(function,function_name); break;
+            case 10 : func_node = parse_function_call<10>(function,function_name); break;
+            case 11 : func_node = parse_function_call<11>(function,function_name); break;
+            case 12 : func_node = parse_function_call<12>(function,function_name); break;
+            case 13 : func_node = parse_function_call<13>(function,function_name); break;
+            case 14 : func_node = parse_function_call<14>(function,function_name); break;
+            case 15 : func_node = parse_function_call<15>(function,function_name); break;
+            case 16 : func_node = parse_function_call<16>(function,function_name); break;
+            case 17 : func_node = parse_function_call<17>(function,function_name); break;
+            case 18 : func_node = parse_function_call<18>(function,function_name); break;
+            case 19 : func_node = parse_function_call<19>(function,function_name); break;
+            case 20 : func_node = parse_function_call<20>(function,function_name); break;
+            default : {
+                         set_error(
+                            make_error(parser_error::e_syntax,
+                                       current_token(),
+                                       "ERR016 - Invalid number of parameters for function: '" + function_name + "'",
+                                       exprtk_error_location));
+
+                         return error_node();
+                      }
+         }
+
+         if (func_node)
+            return func_node;
+         else
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR017 - Failed to generate call to function: '" + function_name + "'",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+      }
+
+      template <std::size_t NumberofParameters>
+      inline expression_node_ptr parse_function_call(ifunction<T>* function, const std::string& function_name)
+      {
+         #ifdef _MSC_VER
+            #pragma warning(push)
+            #pragma warning(disable: 4127)
+         #endif
+         if (0 == NumberofParameters)
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR018 - Expecting ifunction '" + function_name + "' to have non-zero parameter count",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+         #ifdef _MSC_VER
+            #pragma warning(pop)
+         #endif
+
+         expression_node_ptr branch[NumberofParameters];
+         expression_node_ptr result  = error_node();
+
+         std::fill_n(branch, NumberofParameters, reinterpret_cast<expression_node_ptr>(0));
+
+         scoped_delete<expression_node_t,NumberofParameters> sd((*this),branch);
+
+         next_token();
+
+         if (!token_is(token_t::e_lbracket))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR019 - Expecting argument list for function: '" + function_name + "'",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+
+         for (int i = 0; i < static_cast<int>(NumberofParameters); ++i)
+         {
+            branch[i] = parse_expression();
+
+            if (0 == branch[i])
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR020 - Failed to parse argument " + details::to_str(i) + " for function: '" + function_name + "'",
+                             exprtk_error_location));
+
+               return error_node();
+            }
+            else if (i < static_cast<int>(NumberofParameters - 1))
+            {
+               if (!token_is(token_t::e_comma))
+               {
+                  set_error(
+                     make_error(parser_error::e_syntax,
+                                current_token(),
+                                "ERR021 - Invalid number of arguments for function: '" + function_name + "'",
+                                exprtk_error_location));
+
+                  return error_node();
+               }
+            }
+         }
+
+         if (!token_is(token_t::e_rbracket))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR022 - Invalid number of arguments for function: '" + function_name + "'",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+         else
+            result = expression_generator_.function(function,branch);
+
+         sd.delete_ptr = false;
+
+         return result;
+      }
+
+      inline expression_node_ptr parse_function_call_0(ifunction<T>* function, const std::string& function_name)
+      {
+         expression_node_ptr result = expression_generator_.function(function);
+
+         state_.side_effect_present = function->has_side_effects();
+
+         next_token();
+
+         if (
+               token_is(token_t::e_lbracket) &&
+              !token_is(token_t::e_rbracket)
+            )
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR023 - Expecting '()' to proceed call to function: '" + function_name + "'",
+                          exprtk_error_location));
+
+            free_node(node_allocator_,result);
+
+            return error_node();
+         }
+         else
+            return result;
+      }
+
+      template <std::size_t MaxNumberofParameters>
+      inline std::size_t parse_base_function_call(expression_node_ptr (&param_list)[MaxNumberofParameters], const std::string& function_name = "")
+      {
+         std::fill_n(param_list, MaxNumberofParameters, reinterpret_cast<expression_node_ptr>(0));
+
+         scoped_delete<expression_node_t,MaxNumberofParameters> sd((*this),param_list);
+
+         next_token();
+
+         if (!token_is(token_t::e_lbracket))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR024 - Expected a '(' at start of function call to '" + function_name  +
+                          "', instead got: '" + current_token().value + "'",
+                          exprtk_error_location));
+
+            return 0;
+         }
+
+         if (token_is(token_t::e_rbracket, e_hold))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR025 - Expected at least one input parameter for function call '" + function_name + "'",
+                          exprtk_error_location));
+
+            return 0;
+         }
+
+         std::size_t param_index = 0;
+
+         for (; param_index < MaxNumberofParameters; ++param_index)
+         {
+            param_list[param_index] = parse_expression();
+
+            if (0 == param_list[param_index])
+               return 0;
+            else if (token_is(token_t::e_rbracket))
+            {
+               sd.delete_ptr = false;
+               break;
+            }
+            else if (token_is(token_t::e_comma))
+               continue;
+            else
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR026 - Expected a ',' between function input parameters, instead got: '" + current_token().value + "'",
+                             exprtk_error_location));
+
+               return 0;
+            }
+         }
+
+         if (sd.delete_ptr)
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR027 - Invalid number of input parameters passed to function '" + function_name  + "'",
+                          exprtk_error_location));
+
+            return 0;
+         }
+
+         return (param_index + 1);
+      }
+
+      inline expression_node_ptr parse_base_operation()
+      {
+         typedef std::pair<base_ops_map_t::iterator,base_ops_map_t::iterator> map_range_t;
+
+         const std::string operation_name   = current_token().value;
+         const token_t     diagnostic_token = current_token();
+
+         map_range_t itr_range = base_ops_map_.equal_range(operation_name);
+
+         if (0 == std::distance(itr_range.first,itr_range.second))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          diagnostic_token,
+                          "ERR028 - No entry found for base operation: " + operation_name,
+                          exprtk_error_location));
+
+            return error_node();
+         }
+
+         static const std::size_t MaxNumberofParameters = 4;
+         expression_node_ptr param_list[MaxNumberofParameters] = {0};
+
+         const std::size_t parameter_count = parse_base_function_call(param_list, operation_name);
+
+         if ((parameter_count > 0) && (parameter_count <= MaxNumberofParameters))
+         {
+            for (base_ops_map_t::iterator itr = itr_range.first; itr != itr_range.second; ++itr)
+            {
+               const details::base_operation_t& operation = itr->second;
+
+               if (operation.num_params == parameter_count)
+               {
+                  switch (parameter_count)
+                  {
+                     #define base_opr_case(N)                                         \
+                     case N : {                                                       \
+                                 expression_node_ptr pl##N[N] = {0};                  \
+                                 std::copy(param_list, param_list + N, pl##N);        \
+                                 lodge_symbol(operation_name, e_st_function);         \
+                                 return expression_generator_(operation.type, pl##N); \
+                              }                                                       \
+
+                     base_opr_case(1)
+                     base_opr_case(2)
+                     base_opr_case(3)
+                     base_opr_case(4)
+                     #undef base_opr_case
+                  }
+               }
+            }
+         }
+
+         for (std::size_t i = 0; i < MaxNumberofParameters; ++i)
+         {
+            free_node(node_allocator_, param_list[i]);
+         }
+
+         set_error(
+            make_error(parser_error::e_syntax,
+                       diagnostic_token,
+                       "ERR029 - Invalid number of input parameters for call to function: '" + operation_name + "'",
+                       exprtk_error_location));
+
+         return error_node();
+      }
+
+      inline expression_node_ptr parse_conditional_statement_01(expression_node_ptr condition)
+      {
+         // Parse: [if][(][condition][,][consequent][,][alternative][)]
+
+         expression_node_ptr consequent  = error_node();
+         expression_node_ptr alternative = error_node();
+
+         bool result = true;
+
+         if (!token_is(token_t::e_comma))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR030 - Expected ',' between if-statement condition and consequent",
+                          exprtk_error_location));
+            result = false;
+         }
+         else if (0 == (consequent = parse_expression()))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR031 - Failed to parse consequent for if-statement",
+                          exprtk_error_location));
+            result = false;
+         }
+         else if (!token_is(token_t::e_comma))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR032 - Expected ',' between if-statement consequent and alternative",
+                          exprtk_error_location));
+            result = false;
+         }
+         else if (0 == (alternative = parse_expression()))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR033 - Failed to parse alternative for if-statement",
+                          exprtk_error_location));
+            result = false;
+         }
+         else if (!token_is(token_t::e_rbracket))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR034 - Expected ')' at the end of if-statement",
+                          exprtk_error_location));
+            result = false;
+         }
+
+         #ifndef exprtk_disable_string_capabilities
+         if (result)
+         {
+            const bool consq_is_str = is_generally_string_node( consequent);
+            const bool alter_is_str = is_generally_string_node(alternative);
+
+            if (consq_is_str || alter_is_str)
+            {
+               if (consq_is_str && alter_is_str)
+               {
+                  return expression_generator_
+                           .conditional_string(condition, consequent, alternative);
+               }
+
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR035 - Return types of ternary if-statement differ",
+                             exprtk_error_location));
+
+               result = false;
+            }
+         }
+         #endif
+
+         if (!result)
+         {
+            free_node(node_allocator_,  condition);
+            free_node(node_allocator_, consequent);
+            free_node(node_allocator_,alternative);
+
+            return error_node();
+         }
+         else
+            return expression_generator_
+                      .conditional(condition, consequent, alternative);
+      }
+
+      inline expression_node_ptr parse_conditional_statement_02(expression_node_ptr condition)
+      {
+         expression_node_ptr consequent  = error_node();
+         expression_node_ptr alternative = error_node();
+
+         bool result = true;
+
+         if (token_is(token_t::e_lcrlbracket,prsrhlpr_t::e_hold))
+         {
+            if (0 == (consequent = parse_multi_sequence("if-statement-01")))
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR036 - Failed to parse body of consequent for if-statement",
+                             exprtk_error_location));
+
+               result = false;
+            }
+         }
+         else
+         {
+            if (
+                 settings_.commutative_check_enabled() &&
+                 token_is(token_t::e_mul,prsrhlpr_t::e_hold)
+               )
+            {
+               next_token();
+            }
+
+            if (0 != (consequent = parse_expression()))
+            {
+               if (!token_is(token_t::e_eof))
+               {
+                  set_error(
+                     make_error(parser_error::e_syntax,
+                                current_token(),
+                                "ERR037 - Expected ';' at the end of the consequent for if-statement",
+                                exprtk_error_location));
+
+                  result = false;
+               }
+            }
+            else
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR038 - Failed to parse body of consequent for if-statement",
+                             exprtk_error_location));
+
+               result = false;
+            }
+         }
+
+         if (result)
+         {
+            if (details::imatch(current_token().value,"else"))
+            {
+               next_token();
+
+               if (token_is(token_t::e_lcrlbracket,prsrhlpr_t::e_hold))
+               {
+                  if (0 == (alternative = parse_multi_sequence("else-statement-01")))
+                  {
+                     set_error(
+                        make_error(parser_error::e_syntax,
+                                   current_token(),
+                                   "ERR039 - Failed to parse body of the 'else' for if-statement",
+                                   exprtk_error_location));
+
+                     result = false;
+                  }
+               }
+               else if (details::imatch(current_token().value,"if"))
+               {
+                  if (0 == (alternative = parse_conditional_statement()))
+                  {
+                     set_error(
+                        make_error(parser_error::e_syntax,
+                                   current_token(),
+                                   "ERR040 - Failed to parse body of if-else statement",
+                                   exprtk_error_location));
+
+                     result = false;
+                  }
+               }
+               else if (0 != (alternative = parse_expression()))
+               {
+                  if (!token_is(token_t::e_eof))
+                  {
+                     set_error(
+                        make_error(parser_error::e_syntax,
+                                   current_token(),
+                                   "ERR041 - Expected ';' at the end of the 'else-if' for the if-statement",
+                                   exprtk_error_location));
+
+                     result = false;
+                  }
+               }
+               else
+               {
+                  set_error(
+                     make_error(parser_error::e_syntax,
+                                current_token(),
+                                "ERR042 - Failed to parse body of the 'else' for if-statement",
+                                exprtk_error_location));
+
+                  result = false;
+               }
+            }
+         }
+
+         #ifndef exprtk_disable_string_capabilities
+         if (result)
+         {
+            const bool consq_is_str = is_generally_string_node( consequent);
+            const bool alter_is_str = is_generally_string_node(alternative);
+
+            if (consq_is_str || alter_is_str)
+            {
+               if (consq_is_str && alter_is_str)
+               {
+                  return expression_generator_
+                           .conditional_string(condition, consequent, alternative);
+               }
+
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR043 - Return types of ternary if-statement differ",
+                             exprtk_error_location));
+
+               result = false;
+            }
+         }
+         #endif
+
+         if (!result)
+         {
+            free_node(node_allocator_,   condition);
+            free_node(node_allocator_,  consequent);
+            free_node(node_allocator_, alternative);
+
+            return error_node();
+         }
+         else
+            return expression_generator_
+                      .conditional(condition, consequent, alternative);
+      }
+
+      inline expression_node_ptr parse_conditional_statement()
+      {
+         expression_node_ptr condition = error_node();
+
+         next_token();
+
+         if (!token_is(token_t::e_lbracket))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR044 - Expected '(' at start of if-statement, instead got: '" + current_token().value + "'",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+         else if (0 == (condition = parse_expression()))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR045 - Failed to parse condition for if-statement",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+         else if (token_is(token_t::e_comma,prsrhlpr_t::e_hold))
+         {
+            // if (x,y,z)
+            return parse_conditional_statement_01(condition);
+         }
+         else if (token_is(token_t::e_rbracket))
+         {
+            // 00. if (x) y;
+            // 01. if (x) y; else z;
+            // 02. if (x) y; else {z0; ... zn;}
+            // 03. if (x) y; else if (z) w;
+            // 04. if (x) y; else if (z) w; else u;
+            // 05. if (x) y; else if (z) w; else {u0; ... un;}
+            // 06. if (x) y; else if (z) {w0; ... wn;}
+            // 07. if (x) {y0; ... yn;}
+            // 08. if (x) {y0; ... yn;} else z;
+            // 09. if (x) {y0; ... yn;} else {z0; ... zn;};
+            // 10. if (x) {y0; ... yn;} else if (z) w;
+            // 11. if (x) {y0; ... yn;} else if (z) w; else u;
+            // 12. if (x) {y0; ... nex;} else if (z) w; else {u0 ... un;}
+            // 13. if (x) {y0; ... yn;} else if (z) {w0; ... wn;}
+            return parse_conditional_statement_02(condition);
+         }
+
+         set_error(
+            make_error(parser_error::e_syntax,
+                       current_token(),
+                       "ERR046 - Invalid if-statement",
+                       exprtk_error_location));
+
+         free_node(node_allocator_,condition);
+
+         return error_node();
+      }
+
+      inline expression_node_ptr parse_ternary_conditional_statement(expression_node_ptr condition)
+      {
+         // Parse: [condition][?][consequent][:][alternative]
+         expression_node_ptr consequent  = error_node();
+         expression_node_ptr alternative = error_node();
+
+         bool result = true;
+
+         if (0 == condition)
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR047 - Encountered invalid condition branch for ternary if-statement",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+         else if (!token_is(token_t::e_ternary))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR048 - Expected '?' after condition of ternary if-statement",
+                          exprtk_error_location));
+
+            result = false;
+         }
+         else if (0 == (consequent = parse_expression()))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR049 - Failed to parse consequent for ternary if-statement",
+                          exprtk_error_location));
+
+            result = false;
+         }
+         else if (!token_is(token_t::e_colon))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR050 - Expected ':' between ternary if-statement consequent and alternative",
+                          exprtk_error_location));
+
+            result = false;
+         }
+         else if (0 == (alternative = parse_expression()))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR051 - Failed to parse alternative for ternary if-statement",
+                          exprtk_error_location));
+
+            result = false;
+         }
+
+         #ifndef exprtk_disable_string_capabilities
+         if (result)
+         {
+            const bool consq_is_str = is_generally_string_node( consequent);
+            const bool alter_is_str = is_generally_string_node(alternative);
+
+            if (consq_is_str || alter_is_str)
+            {
+               if (consq_is_str && alter_is_str)
+               {
+                  return expression_generator_
+                           .conditional_string(condition, consequent, alternative);
+               }
+
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR052 - Return types of ternary if-statement differ",
+                             exprtk_error_location));
+
+               result = false;
+            }
+         }
+         #endif
+
+         if (!result)
+         {
+            free_node(node_allocator_,   condition);
+            free_node(node_allocator_,  consequent);
+            free_node(node_allocator_, alternative);
+
+            return error_node();
+         }
+         else
+            return expression_generator_
+                      .conditional(condition, consequent, alternative);
+      }
+
+      inline expression_node_ptr parse_not_statement()
+      {
+         if (settings_.logic_disabled("not"))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR053 - Invalid or disabled logic operation 'not'",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+
+         return parse_base_operation();
+      }
+
+      inline expression_node_ptr parse_while_loop()
+      {
+         // Parse: [while][(][test expr][)][{][expression][}]
+         expression_node_ptr condition   = error_node();
+         expression_node_ptr branch      = error_node();
+         expression_node_ptr result_node = error_node();
+
+         bool result = true;
+
+         next_token();
+
+         if (!token_is(token_t::e_lbracket))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR054 - Expected '(' at start of while-loop condition statement",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+         else if (0 == (condition = parse_expression()))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR055 - Failed to parse condition for while-loop",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+         else if (!token_is(token_t::e_rbracket))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR056 - Expected ')' at end of while-loop condition statement",
+                          exprtk_error_location));
+
+            result = false;
+         }
+
+         brkcnt_list_.push_front(false);
+
+         if (result)
+         {
+            if (0 == (branch = parse_multi_sequence("while-loop")))
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR057 - Failed to parse body of while-loop"));
+               result = false;
+            }
+            else if (0 == (result_node = expression_generator_.while_loop(condition,
+                                                                          branch,
+                                                                          brkcnt_list_.front())))
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR058 - Failed to synthesize while-loop",
+                             exprtk_error_location));
+
+               result = false;
+            }
+         }
+
+         if (!result)
+         {
+            free_node(node_allocator_,      branch);
+            free_node(node_allocator_,   condition);
+            free_node(node_allocator_, result_node);
+
+            brkcnt_list_.pop_front();
+
+            return error_node();
+         }
+         else
+            return result_node;
+      }
+
+      inline expression_node_ptr parse_repeat_until_loop()
+      {
+         // Parse: [repeat][{][expression][}][until][(][test expr][)]
+         expression_node_ptr condition = error_node();
+         expression_node_ptr branch    = error_node();
+         next_token();
+
+         std::vector<expression_node_ptr> arg_list;
+         std::vector<bool> side_effect_list;
+
+         scoped_vec_delete<expression_node_t> sdd((*this),arg_list);
+
+         brkcnt_list_.push_front(false);
+
+         if (details::imatch(current_token().value,"until"))
+         {
+            next_token();
+            branch = node_allocator_.allocate<details::null_node<T> >();
+         }
+         else
+         {
+            const token_t::token_type seperator = token_t::e_eof;
+
+            scope_handler sh(*this);
+
+            scoped_bool_or_restorer sbr(state_.side_effect_present);
+
+            for ( ; ; )
+            {
+               state_.side_effect_present = false;
+
+               expression_node_ptr arg = parse_expression();
+
+               if (0 == arg)
+                  return error_node();
+               else
+               {
+                  arg_list.push_back(arg);
+                  side_effect_list.push_back(state_.side_effect_present);
+               }
+
+               if (details::imatch(current_token().value,"until"))
+               {
+                  next_token();
+                  break;
+               }
+
+               const bool is_next_until = peek_token_is(token_t::e_symbol) &&
+                                          peek_token_is("until");
+
+               if (!token_is(seperator) && is_next_until)
+               {
+                  set_error(
+                     make_error(parser_error::e_syntax,
+                                current_token(),
+                                "ERR059 - Expected '" + token_t::to_str(seperator) + "' in body of repeat until loop",
+                                exprtk_error_location));
+
+                  return error_node();
+               }
+
+               if (details::imatch(current_token().value,"until"))
+               {
+                  next_token();
+                  break;
+               }
+            }
+
+            branch = simplify(arg_list,side_effect_list);
+
+            sdd.delete_ptr = (0 == branch);
+
+            if (sdd.delete_ptr)
+            {
+               brkcnt_list_.pop_front();
+
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR060 - Failed to parse body of repeat until loop",
+                             exprtk_error_location));
+
+               return error_node();
+            }
+         }
+
+         if (!token_is(token_t::e_lbracket))
+         {
+            brkcnt_list_.pop_front();
+
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR061 - Expected '(' before condition statement of repeat until loop",
+                          exprtk_error_location));
+
+            free_node(node_allocator_,branch);
+
+            return error_node();
+         }
+         else if (0 == (condition = parse_expression()))
+         {
+            brkcnt_list_.pop_front();
+
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR062 - Failed to parse condition for repeat until loop",
+                          exprtk_error_location));
+
+            free_node(node_allocator_,branch);
+
+            return error_node();
+         }
+         else if (!token_is(token_t::e_rbracket))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR063 - Expected ')' after condition of repeat until loop",
+                          exprtk_error_location));
+
+            free_node(node_allocator_,    branch);
+            free_node(node_allocator_, condition);
+
+            brkcnt_list_.pop_front();
+
+            return error_node();
+         }
+
+         expression_node_ptr result;
+
+         result = expression_generator_
+                     .repeat_until_loop(condition, branch, brkcnt_list_.front());
+
+         if (0 == result)
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR064 - Failed to synthesize repeat until loop",
+                          exprtk_error_location));
+
+            free_node(node_allocator_,condition);
+
+            brkcnt_list_.pop_front();
+
+            return error_node();
+         }
+         else
+         {
+            brkcnt_list_.pop_front();
+            return result;
+         }
+      }
+
+      inline expression_node_ptr parse_for_loop()
+      {
+         expression_node_ptr initialiser = error_node();
+         expression_node_ptr condition   = error_node();
+         expression_node_ptr incrementor = error_node();
+         expression_node_ptr loop_body   = error_node();
+
+         scope_element* se = 0;
+         bool result       = true;
+
+         next_token();
+
+         scope_handler sh(*this);
+
+         if (!token_is(token_t::e_lbracket))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR065 - Expected '(' at start of for-loop",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+
+         if (!token_is(token_t::e_eof))
+         {
+            if (
+                 !token_is(token_t::e_symbol,prsrhlpr_t::e_hold) &&
+                 details::imatch(current_token().value,"var")
+               )
+            {
+               next_token();
+
+               if (!token_is(token_t::e_symbol,prsrhlpr_t::e_hold))
+               {
+                  set_error(
+                     make_error(parser_error::e_syntax,
+                                current_token(),
+                                "ERR066 - Expected a variable at the start of initialiser section of for-loop",
+                                exprtk_error_location));
+
+                  return error_node();
+               }
+               else if (!peek_token_is(token_t::e_assign))
+               {
+                  set_error(
+                     make_error(parser_error::e_syntax,
+                                current_token(),
+                                "ERR067 - Expected variable assignment of initialiser section of for-loop",
+                                exprtk_error_location));
+
+                  return error_node();
+               }
+
+               const std::string loop_counter_symbol = current_token().value;
+
+               se = &sem_.get_element(loop_counter_symbol);
+
+               if ((se->name == loop_counter_symbol) && se->active)
+               {
+                  set_error(
+                     make_error(parser_error::e_syntax,
+                                current_token(),
+                                "ERR068 - For-loop variable '" + loop_counter_symbol+ "' is being shadowed by a previous declaration",
+                                exprtk_error_location));
+
+                  return error_node();
+               }
+               else if (!symtab_store_.is_variable(loop_counter_symbol))
+               {
+                  if (
+                       !se->active &&
+                       (se->name == loop_counter_symbol) &&
+                       (se->type ==  scope_element::e_variable)
+                     )
+                  {
+                     se->active = true;
+                     se->ref_count++;
+                  }
+                  else
+                  {
+                     scope_element nse;
+                     nse.name      = loop_counter_symbol;
+                     nse.active    = true;
+                     nse.ref_count = 1;
+                     nse.type      = scope_element::e_variable;
+                     nse.depth     = state_.scope_depth;
+                     nse.data      = new T(T(0));
+                     nse.var_node  = node_allocator_.allocate<variable_node_t>(*(T*)(nse.data));
+
+                     if (!sem_.add_element(nse))
+                     {
+                        set_error(
+                           make_error(parser_error::e_syntax,
+                                      current_token(),
+                                      "ERR069 - Failed to add new local variable '" + loop_counter_symbol + "' to SEM",
+                                      exprtk_error_location));
+
+                        sem_.free_element(nse);
+
+                        result = false;
+                     }
+                     else
+                     {
+                        exprtk_debug(("parse_for_loop() - INFO - Added new local variable: %s\n",nse.name.c_str()));
+
+                        state_.activate_side_effect("parse_for_loop()");
+                     }
+                  }
+               }
+            }
+
+            if (0 == (initialiser = parse_expression()))
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR070 - Failed to parse initialiser of for-loop",
+                             exprtk_error_location));
+
+               result = false;
+            }
+            else if (!token_is(token_t::e_eof))
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR071 - Expected ';' after initialiser of for-loop",
+                             exprtk_error_location));
+
+               result = false;
+            }
+         }
+
+         if (!token_is(token_t::e_eof))
+         {
+            if (0 == (condition = parse_expression()))
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR072 - Failed to parse condition of for-loop",
+                             exprtk_error_location));
+
+               result = false;
+            }
+            else if (!token_is(token_t::e_eof))
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR073 - Expected ';' after condition section of for-loop",
+                             exprtk_error_location));
+
+               result = false;
+            }
+         }
+
+         if (!token_is(token_t::e_rbracket))
+         {
+            if (0 == (incrementor = parse_expression()))
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR074 - Failed to parse incrementor of for-loop",
+                             exprtk_error_location));
+
+               result = false;
+            }
+            else if (!token_is(token_t::e_rbracket))
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR075 - Expected ')' after incrementor section of for-loop",
+                             exprtk_error_location));
+
+               result = false;
+            }
+         }
+
+         if (result)
+         {
+            brkcnt_list_.push_front(false);
+
+            if (0 == (loop_body = parse_multi_sequence("for-loop")))
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR076 - Failed to parse body of for-loop",
+                             exprtk_error_location));
+
+               result = false;
+            }
+         }
+
+         if (!result)
+         {
+            if (se)
+            {
+               se->ref_count--;
+            }
+
+            free_node(node_allocator_, initialiser);
+            free_node(node_allocator_,   condition);
+            free_node(node_allocator_, incrementor);
+            free_node(node_allocator_,   loop_body);
+
+            if (!brkcnt_list_.empty())
+            {
+               brkcnt_list_.pop_front();
+            }
+
+            return error_node();
+         }
+         else
+         {
+            expression_node_ptr result_node =
+               expression_generator_.for_loop(initialiser,
+                                              condition,
+                                              incrementor,
+                                              loop_body,
+                                              brkcnt_list_.front());
+            brkcnt_list_.pop_front();
+
+            return result_node;
+         }
+      }
+
+      inline expression_node_ptr parse_switch_statement()
+      {
+         std::vector<expression_node_ptr> arg_list;
+         expression_node_ptr result = error_node();
+
+         if (!details::imatch(current_token().value,"switch"))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR077 - Expected keyword 'switch'",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+
+         scoped_vec_delete<expression_node_t> svd((*this),arg_list);
+
+         next_token();
+
+         if (!token_is(token_t::e_lcrlbracket))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR078 - Expected '{' for call to switch statement",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+
+         for ( ; ; )
+         {
+            if (!details::imatch("case",current_token().value))
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR079 - Expected either a 'case' or 'default' statement",
+                             exprtk_error_location));
+
+               return error_node();
+            }
+
+            next_token();
+
+            expression_node_ptr condition = parse_expression();
+
+            if (0 == condition)
+               return error_node();
+            else if (!token_is(token_t::e_colon))
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR080 - Expected ':' for case of switch statement",
+                             exprtk_error_location));
+
+               return error_node();
+            }
+
+            expression_node_ptr consequent = parse_expression();
+
+            if (0 == consequent)
+               return error_node();
+            else if (!token_is(token_t::e_eof))
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR081 - Expected ';' at end of case for switch statement",
+                             exprtk_error_location));
+
+               return error_node();
+            }
+
+            // Can we optimise away the case statement?
+            if (is_constant_node(condition) && is_false(condition))
+            {
+               free_node(node_allocator_,  condition);
+               free_node(node_allocator_, consequent);
+            }
+            else
+            {
+               arg_list.push_back( condition);
+               arg_list.push_back(consequent);
+            }
+
+            if (details::imatch("default",current_token().value))
+            {
+               next_token();
+               if (!token_is(token_t::e_colon))
+               {
+                  set_error(
+                     make_error(parser_error::e_syntax,
+                                current_token(),
+                                "ERR082 - Expected ':' for default of switch statement",
+                                exprtk_error_location));
+
+                  return error_node();
+               }
+
+               expression_node_ptr default_statement = error_node();
+
+               if (token_is(token_t::e_lcrlbracket,prsrhlpr_t::e_hold))
+                  default_statement = parse_multi_sequence("switch-default");
+               else
+                  default_statement = parse_expression();
+
+               if (0 == default_statement)
+                  return error_node();
+               else if (!token_is(token_t::e_eof))
+               {
+                  free_node(node_allocator_,default_statement);
+
+                  set_error(
+                     make_error(parser_error::e_syntax,
+                                current_token(),
+                                "ERR083 - Expected ';' at end of default for switch statement",
+                                exprtk_error_location));
+
+                  return error_node();
+               }
+
+               arg_list.push_back(default_statement);
+               break;
+            }
+         }
+
+         if (!token_is(token_t::e_rcrlbracket))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR084 - Expected '}' at end of switch statement",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+
+         result = expression_generator_.switch_statement(arg_list);
+
+         svd.delete_ptr = (0 == result);
+
+         return result;
+      }
+
+      inline expression_node_ptr parse_multi_switch_statement()
+      {
+         std::vector<expression_node_ptr> arg_list;
+
+         if (!details::imatch(current_token().value,"[*]"))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR085 - Expected token '[*]'",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+
+         scoped_vec_delete<expression_node_t> svd((*this),arg_list);
+
+         next_token();
+
+         if (!token_is(token_t::e_lcrlbracket))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR086 - Expected '{' for call to [*] statement",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+
+         for ( ; ; )
+         {
+            if (!details::imatch("case",current_token().value))
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR087 - Expected a 'case' statement for multi-switch",
+                             exprtk_error_location));
+
+               return error_node();
+            }
+
+            next_token();
+
+            expression_node_ptr condition = parse_expression();
+
+            if (0 == condition)
+               return error_node();
+
+            if (!token_is(token_t::e_colon))
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR088 - Expected ':' for case of [*] statement",
+                             exprtk_error_location));
+
+               return error_node();
+            }
+
+            expression_node_ptr consequent = parse_expression();
+
+            if (0 == consequent)
+               return error_node();
+
+            if (!token_is(token_t::e_eof))
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR089 - Expected ';' at end of case for [*] statement",
+                             exprtk_error_location));
+
+               return error_node();
+            }
+
+            // Can we optimise away the case statement?
+            if (is_constant_node(condition) && is_false(condition))
+            {
+               free_node(node_allocator_,  condition);
+               free_node(node_allocator_, consequent);
+            }
+            else
+            {
+               arg_list.push_back( condition);
+               arg_list.push_back(consequent);
+            }
+
+            if (token_is(token_t::e_rcrlbracket,prsrhlpr_t::e_hold))
+            {
+               break;
+            }
+         }
+
+         if (!token_is(token_t::e_rcrlbracket))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR090 - Expected '}' at end of [*] statement",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+
+         const expression_node_ptr result = expression_generator_.multi_switch_statement(arg_list);
+
+         svd.delete_ptr = (0 == result);
+
+         return result;
+      }
+
+      inline expression_node_ptr parse_vararg_function()
+      {
+         std::vector<expression_node_ptr> arg_list;
+
+         details::operator_type opt_type = details::e_default;
+         const std::string symbol = current_token().value;
+
+         if (details::imatch(symbol,"~"))
+         {
+            next_token();
+            return parse_multi_sequence();
+         }
+         else if (details::imatch(symbol,"[*]"))
+         {
+            return parse_multi_switch_statement();
+         }
+         else if (details::imatch(symbol, "avg" )) opt_type = details::e_avg ;
+         else if (details::imatch(symbol, "mand")) opt_type = details::e_mand;
+         else if (details::imatch(symbol, "max" )) opt_type = details::e_max ;
+         else if (details::imatch(symbol, "min" )) opt_type = details::e_min ;
+         else if (details::imatch(symbol, "mor" )) opt_type = details::e_mor ;
+         else if (details::imatch(symbol, "mul" )) opt_type = details::e_prod;
+         else if (details::imatch(symbol, "sum" )) opt_type = details::e_sum ;
+         else
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR091 - Unsupported vararg function: " + symbol,
+                          exprtk_error_location));
+
+            return error_node();
+         }
+
+         scoped_vec_delete<expression_node_t> sdd((*this),arg_list);
+
+         lodge_symbol(symbol, e_st_function);
+
+         next_token();
+
+         if (!token_is(token_t::e_lbracket))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR092 - Expected '(' for call to vararg function: " + symbol,
+                          exprtk_error_location));
+
+            return error_node();
+         }
+
+         for ( ; ; )
+         {
+            expression_node_ptr arg = parse_expression();
+
+            if (0 == arg)
+               return error_node();
+            else
+               arg_list.push_back(arg);
+
+            if (token_is(token_t::e_rbracket))
+               break;
+            else if (!token_is(token_t::e_comma))
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR093 - Expected ',' for call to vararg function: " + symbol,
+                             exprtk_error_location));
+
+               return error_node();
+            }
+         }
+
+         const expression_node_ptr result = expression_generator_.vararg_function(opt_type,arg_list);
+
+         sdd.delete_ptr = (0 == result);
+         return result;
+      }
+
+      #ifndef exprtk_disable_string_capabilities
+      inline expression_node_ptr parse_string_range_statement(expression_node_ptr& expression)
+      {
+         if (!token_is(token_t::e_lsqrbracket))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR094 - Expected '[' as start of string range definition",
+                          exprtk_error_location));
+
+            free_node(node_allocator_,expression);
+
+            return error_node();
+         }
+         else if (token_is(token_t::e_rsqrbracket))
+         {
+            return node_allocator_.allocate<details::string_size_node<T> >(expression);
+         }
+
+         range_t rp;
+
+         if (!parse_range(rp,true))
+         {
+            free_node(node_allocator_,expression);
+
+            return error_node();
+         }
+
+         expression_node_ptr result = expression_generator_(expression,rp);
+
+         if (0 == result)
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR095 - Failed to generate string range node",
+                          exprtk_error_location));
+
+            free_node(node_allocator_,expression);
+         }
+
+         rp.clear();
+
+         return result;
+      }
+      #else
+      inline expression_node_ptr parse_string_range_statement(expression_node_ptr&)
+      {
+         return error_node();
+      }
+      #endif
+
+      inline void parse_pending_string_rangesize(expression_node_ptr& expression)
+      {
+         // Allow no more than 100 range calls, eg: s[][][]...[][]
+         const std::size_t max_rangesize_parses = 100;
+
+         std::size_t i = 0;
+
+         while
+            (
+              (0 != expression)                     &&
+              (i++ < max_rangesize_parses)          &&
+              error_list_.empty()                   &&
+              is_generally_string_node(expression)  &&
+              token_is(token_t::e_lsqrbracket,prsrhlpr_t::e_hold)
+            )
+         {
+            expression = parse_string_range_statement(expression);
+         }
+      }
+
+      template <typename Allocator1,
+                typename Allocator2,
+                template <typename, typename> class Sequence>
+      inline expression_node_ptr simplify(Sequence<expression_node_ptr,Allocator1>& expression_list,
+                                          Sequence<bool,Allocator2>& side_effect_list,
+                                          const bool specialise_on_final_type = false)
+      {
+         if (expression_list.empty())
+            return error_node();
+         else if (1 == expression_list.size())
+            return expression_list[0];
+
+         Sequence<expression_node_ptr,Allocator1> tmp_expression_list;
+
+         bool return_node_present = false;
+
+         for (std::size_t i = 0; i < (expression_list.size() - 1); ++i)
+         {
+            if (is_variable_node(expression_list[i]))
+               continue;
+            else if (
+                      is_return_node  (expression_list[i]) ||
+                      is_break_node   (expression_list[i]) ||
+                      is_continue_node(expression_list[i])
+                    )
+            {
+               tmp_expression_list.push_back(expression_list[i]);
+
+               // Remove all subexpressions after first short-circuit
+               // node has been encountered.
+
+               for (std::size_t j = i + 1; j < expression_list.size(); ++j)
+               {
+                  free_node(node_allocator_,expression_list[j]);
+               }
+
+               return_node_present = true;
+
+               break;
+            }
+            else if (
+                      is_constant_node(expression_list[i]) ||
+                      is_null_node    (expression_list[i]) ||
+                      !side_effect_list[i]
+                    )
+            {
+               free_node(node_allocator_,expression_list[i]);
+               continue;
+            }
+            else
+               tmp_expression_list.push_back(expression_list[i]);
+         }
+
+         if (!return_node_present)
+         {
+            tmp_expression_list.push_back(expression_list.back());
+         }
+
+         expression_list.swap(tmp_expression_list);
+
+         if (tmp_expression_list.size() > expression_list.size())
+         {
+            exprtk_debug(("simplify() - Reduced subexpressions from %d to %d\n",
+                          static_cast<int>(tmp_expression_list.size()),
+                          static_cast<int>(expression_list    .size())));
+         }
+
+         if (
+              return_node_present          ||
+              side_effect_list.back()      ||
+              (expression_list.size() > 1)
+            )
+            state_.activate_side_effect("simplify()");
+
+         if (1 == expression_list.size())
+            return expression_list[0];
+         else if (specialise_on_final_type && is_generally_string_node(expression_list.back()))
+            return expression_generator_.vararg_function(details::e_smulti,expression_list);
+         else
+            return expression_generator_.vararg_function(details::e_multi,expression_list);
+      }
+
+      inline expression_node_ptr parse_multi_sequence(const std::string& source = "")
+      {
+         token_t::token_type close_bracket = token_t::e_rcrlbracket;
+         token_t::token_type seperator     = token_t::e_eof;
+
+         if (!token_is(token_t::e_lcrlbracket))
+         {
+            if (token_is(token_t::e_lbracket))
+            {
+               close_bracket = token_t::e_rbracket;
+               seperator     = token_t::e_comma;
+            }
+            else
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR096 - Expected '" + token_t::to_str(close_bracket) + "' for call to multi-sequence" +
+                             ((!source.empty()) ? std::string(" section of " + source): ""),
+                             exprtk_error_location));
+
+               return error_node();
+            }
+         }
+         else if (token_is(token_t::e_rcrlbracket))
+         {
+            return node_allocator_.allocate<details::null_node<T> >();
+         }
+
+         std::vector<expression_node_ptr> arg_list;
+         std::vector<bool> side_effect_list;
+
+         expression_node_ptr result = error_node();
+
+         scoped_vec_delete<expression_node_t> sdd((*this),arg_list);
+
+         scope_handler sh(*this);
+
+         scoped_bool_or_restorer sbr(state_.side_effect_present);
+
+         for ( ; ; )
+         {
+            state_.side_effect_present = false;
+
+            expression_node_ptr arg = parse_expression();
+
+            if (0 == arg)
+               return error_node();
+            else
+            {
+               arg_list.push_back(arg);
+               side_effect_list.push_back(state_.side_effect_present);
+            }
+
+            if (token_is(close_bracket))
+               break;
+
+            const bool is_next_close = peek_token_is(close_bracket);
+
+            if (!token_is(seperator) && is_next_close)
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR097 - Expected '" + details::to_str(seperator) + "' for call to multi-sequence section of " + source,
+                             exprtk_error_location));
+
+               return error_node();
+            }
+
+            if (token_is(close_bracket))
+               break;
+         }
+
+         result = simplify(arg_list,side_effect_list,source.empty());
+
+         sdd.delete_ptr = (0 == result);
+         return result;
+      }
+
+      inline bool parse_range(range_t& rp, const bool skip_lsqr = false)
+      {
+         // Examples of valid ranges:
+         // 1. [1:5]     -> 1..5
+         // 2. [ :5]     -> 0..5
+         // 3. [1: ]     -> 1..end
+         // 4. [x:y]     -> x..y where x <= y
+         // 5. [x+1:y/2] -> x+1..y/2 where x+1 <= y/2
+         // 6. [ :y]     -> 0..y where 0 <= y
+         // 7. [x: ]     -> x..end where x <= end
+
+         rp.clear();
+
+         if (!skip_lsqr && !token_is(token_t::e_lsqrbracket))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR098 - Expected '[' for start of range",
+                          exprtk_error_location));
+
+            return false;
+         }
+
+         if (token_is(token_t::e_colon))
+         {
+            rp.n0_c.first  = true;
+            rp.n0_c.second = 0;
+            rp.cache.first = 0;
+         }
+         else
+         {
+            expression_node_ptr r0 = parse_expression();
+
+            if (0 == r0)
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR099 - Failed parse begin section of range",
+                             exprtk_error_location));
+
+               return false;
+            }
+            else if (is_constant_node(r0))
+            {
+               const T r0_value = r0->value();
+
+               if (r0_value >= T(0))
+               {
+                  rp.n0_c.first  = true;
+                  rp.n0_c.second = static_cast<std::size_t>(details::numeric::to_int64(r0_value));
+                  rp.cache.first = rp.n0_c.second;
+               }
+
+               free_node(node_allocator_,r0);
+
+               if (r0_value < T(0))
+               {
+                  set_error(
+                     make_error(parser_error::e_syntax,
+                                current_token(),
+                                "ERR100 - Range lower bound less than zero! Constraint: r0 >= 0",
+                                exprtk_error_location));
+
+                  return false;
+               }
+            }
+            else
+            {
+               rp.n0_e.first  = true;
+               rp.n0_e.second = r0;
+            }
+
+            if (!token_is(token_t::e_colon))
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR101 - Expected ':' for break  in range",
+                             exprtk_error_location));
+
+               rp.free();
+
+               return false;
+            }
+         }
+
+         if (token_is(token_t::e_rsqrbracket))
+         {
+            rp.n1_c.first  = true;
+            rp.n1_c.second = std::numeric_limits<std::size_t>::max();
+         }
+         else
+         {
+            expression_node_ptr r1 = parse_expression();
+
+            if (0 == r1)
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR102 - Failed parse end section of range",
+                             exprtk_error_location));
+
+               rp.free();
+
+               return false;
+            }
+            else if (is_constant_node(r1))
+            {
+               const T r1_value = r1->value();
+
+               if (r1_value >= T(0))
+               {
+                  rp.n1_c.first   = true;
+                  rp.n1_c.second  = static_cast<std::size_t>(details::numeric::to_int64(r1_value));
+                  rp.cache.second = rp.n1_c.second;
+               }
+
+               free_node(node_allocator_,r1);
+
+               if (r1_value < T(0))
+               {
+                  set_error(
+                     make_error(parser_error::e_syntax,
+                                current_token(),
+                                "ERR103 - Range upper bound less than zero! Constraint: r1 >= 0",
+                                exprtk_error_location));
+
+                  return false;
+               }
+            }
+            else
+            {
+               rp.n1_e.first  = true;
+               rp.n1_e.second = r1;
+            }
+
+            if (!token_is(token_t::e_rsqrbracket))
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR104 - Expected ']' for start of range",
+                             exprtk_error_location));
+
+               rp.free();
+
+               return false;
+            }
+         }
+
+         if (rp.const_range())
+         {
+            std::size_t r0 = 0;
+            std::size_t r1 = 0;
+
+            const bool rp_result = rp(r0,r1);
+
+            if (!rp_result || (r0 > r1))
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR105 - Invalid range, Constraint: r0 <= r1",
+                             exprtk_error_location));
+
+               return false;
+            }
+         }
+
+         return true;
+      }
+
+      inline void lodge_symbol(const std::string& symbol,
+                               const symbol_type st)
+      {
+         dec_.add_symbol(symbol,st);
+      }
+
+      #ifndef exprtk_disable_string_capabilities
+      inline expression_node_ptr parse_string()
+      {
+         const std::string symbol = current_token().value;
+
+         typedef details::stringvar_node<T>* strvar_node_t;
+
+         expression_node_ptr result   = error_node();
+         strvar_node_t const_str_node = static_cast<strvar_node_t>(0);
+
+         scope_element& se = sem_.get_active_element(symbol);
+
+         if (scope_element::e_string == se.type)
+         {
+            se.active = true;
+            result    = se.str_node;
+            lodge_symbol(symbol, e_st_local_string);
+         }
+         else
+         {
+            if (!symtab_store_.is_conststr_stringvar(symbol))
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR106 - Unknown string symbol",
+                             exprtk_error_location));
+
+               return error_node();
+            }
+
+            result = symtab_store_.get_stringvar(symbol);
+
+            if (symtab_store_.is_constant_string(symbol))
+            {
+               const_str_node = static_cast<strvar_node_t>(result);
+               result = expression_generator_(const_str_node->str());
+            }
+
+            lodge_symbol(symbol, e_st_string);
+         }
+
+         if (peek_token_is(token_t::e_lsqrbracket))
+         {
+            next_token();
+
+            if (peek_token_is(token_t::e_rsqrbracket))
+            {
+               next_token();
+               next_token();
+
+               if (const_str_node)
+               {
+                  free_node(node_allocator_,result);
+
+                  return expression_generator_(T(const_str_node->size()));
+               }
+               else
+                  return node_allocator_.allocate<details::stringvar_size_node<T> >
+                            (static_cast<details::stringvar_node<T>*>(result)->ref());
+            }
+
+            range_t rp;
+
+            if (!parse_range(rp))
+            {
+               free_node(node_allocator_,result);
+
+               return error_node();
+            }
+            else if (const_str_node)
+            {
+               free_node(node_allocator_,result);
+               result = expression_generator_(const_str_node->ref(),rp);
+            }
+            else
+               result = expression_generator_(static_cast<details::stringvar_node<T>*>
+                           (result)->ref(), rp);
+
+            if (result)
+               rp.clear();
+         }
+         else
+            next_token();
+
+         return result;
+      }
+      #else
+      inline expression_node_ptr parse_string()
+      {
+         return error_node();
+      }
+      #endif
+
+      #ifndef exprtk_disable_string_capabilities
+      inline expression_node_ptr parse_const_string()
+      {
+         const std::string   const_str = current_token().value;
+         expression_node_ptr result    = expression_generator_(const_str);
+
+         if (peek_token_is(token_t::e_lsqrbracket))
+         {
+            next_token();
+
+            if (peek_token_is(token_t::e_rsqrbracket))
+            {
+               next_token();
+               next_token();
+
+               free_node(node_allocator_,result);
+
+               return expression_generator_(T(const_str.size()));
+            }
+
+            range_t rp;
+
+            if (!parse_range(rp))
+            {
+               free_node(node_allocator_,result);
+
+               return error_node();
+            }
+
+            free_node(node_allocator_,result);
+
+            if (rp.n1_c.first && (rp.n1_c.second == std::numeric_limits<std::size_t>::max()))
+            {
+               rp.n1_c.second  = const_str.size() - 1;
+               rp.cache.second = rp.n1_c.second;
+            }
+
+            if (
+                 (rp.n0_c.first && (rp.n0_c.second >= const_str.size())) ||
+                 (rp.n1_c.first && (rp.n1_c.second >= const_str.size()))
+               )
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR107 - Overflow in range for string: '" + const_str + "'[" +
+                             (rp.n0_c.first ? details::to_str(static_cast<int>(rp.n0_c.second)) : "?") + ":" +
+                             (rp.n1_c.first ? details::to_str(static_cast<int>(rp.n1_c.second)) : "?") + "]",
+                             exprtk_error_location));
+
+               return error_node();
+            }
+
+            result = expression_generator_(const_str,rp);
+
+            if (result)
+               rp.clear();
+         }
+         else
+            next_token();
+
+         return result;
+      }
+      #else
+      inline expression_node_ptr parse_const_string()
+      {
+         return error_node();
+      }
+      #endif
+
+      inline expression_node_ptr parse_vector()
+      {
+         const std::string symbol = current_token().value;
+
+         vector_holder_ptr vec = vector_holder_ptr(0);
+
+         const scope_element& se = sem_.get_active_element(symbol);
+
+         if (
+              !details::imatch(se.name, symbol) ||
+              (se.depth > state_.scope_depth)   ||
+              (scope_element::e_vector != se.type)
+            )
+         {
+            if (0 == (vec = symtab_store_.get_vector(symbol)))
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR108 - Symbol '" + symbol+ " not a vector",
+                             exprtk_error_location));
+
+               return error_node();
+            }
+         }
+         else
+            vec = se.vec_node;
+
+         expression_node_ptr index_expr = error_node();
+
+         next_token();
+
+         if (!token_is(token_t::e_lsqrbracket))
+         {
+            return node_allocator_.allocate<vector_node_t>(vec);
+         }
+         else if (token_is(token_t::e_rsqrbracket))
+         {
+            return expression_generator_(T(vec->size()));
+         }
+         else if (0 == (index_expr = parse_expression()))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR109 - Failed to parse index for vector: '" + symbol + "'",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+         else if (!token_is(token_t::e_rsqrbracket))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR110 - Expected ']' for index of vector: '" + symbol + "'",
+                          exprtk_error_location));
+
+            free_node(node_allocator_,index_expr);
+
+            return error_node();
+         }
+
+         // Perform compile-time range check
+         if (details::is_constant_node(index_expr))
+         {
+            const std::size_t index    = static_cast<std::size_t>(details::numeric::to_int32(index_expr->value()));
+            const std::size_t vec_size = vec->size();
+
+            if (index >= vec_size)
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR111 - Index of " + details::to_str(index) + " out of range for "
+                             "vector '" + symbol + "' of size " + details::to_str(vec_size),
+                             exprtk_error_location));
+
+               free_node(node_allocator_,index_expr);
+
+               return error_node();
+            }
+         }
+
+         return expression_generator_.vector_element(symbol, vec, index_expr);
+      }
+
+      inline expression_node_ptr parse_vararg_function_call(ivararg_function<T>* vararg_function, const std::string& vararg_function_name)
+      {
+         std::vector<expression_node_ptr> arg_list;
+
+         expression_node_ptr result = error_node();
+
+         scoped_vec_delete<expression_node_t> sdd((*this),arg_list);
+
+         next_token();
+
+         if (token_is(token_t::e_lbracket))
+         {
+            if (token_is(token_t::e_rbracket))
+            {
+               if (!vararg_function->allow_zero_parameters())
+               {
+                  set_error(
+                     make_error(parser_error::e_syntax,
+                                current_token(),
+                                "ERR112 - Zero parameter call to vararg function: "
+                                + vararg_function_name + " not allowed",
+                                exprtk_error_location));
+
+                  return error_node();
+               }
+            }
+            else
+            {
+               for ( ; ; )
+               {
+                  expression_node_ptr arg = parse_expression();
+
+                  if (0 == arg)
+                     return error_node();
+                  else
+                     arg_list.push_back(arg);
+
+                  if (token_is(token_t::e_rbracket))
+                     break;
+                  else if (!token_is(token_t::e_comma))
+                  {
+                     set_error(
+                        make_error(parser_error::e_syntax,
+                                   current_token(),
+                                   "ERR113 - Expected ',' for call to vararg function: "
+                                   + vararg_function_name,
+                                   exprtk_error_location));
+
+                     return error_node();
+                  }
+               }
+            }
+         }
+         else if (!vararg_function->allow_zero_parameters())
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR114 - Zero parameter call to vararg function: "
+                          + vararg_function_name + " not allowed",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+
+         if (arg_list.size() < vararg_function->min_num_args())
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR115 - Invalid number of parameters to call to vararg function: "
+                          + vararg_function_name + ", require at least "
+                          + details::to_str(static_cast<int>(vararg_function->min_num_args())) + " parameters",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+         else if (arg_list.size() > vararg_function->max_num_args())
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR116 - Invalid number of parameters to call to vararg function: "
+                          + vararg_function_name + ", require no more than "
+                          + details::to_str(static_cast<int>(vararg_function->max_num_args())) + " parameters",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+
+         result = expression_generator_.vararg_function_call(vararg_function,arg_list);
+
+         sdd.delete_ptr = (0 == result);
+
+         return result;
+      }
+
+      class type_checker
+      {
+      public:
+
+         enum return_type_t
+         {
+            e_overload = ' ',
+            e_numeric  = 'T',
+            e_string   = 'S'
+         };
+
+         struct function_prototype_t
+         {
+             return_type_t return_type;
+             std::string   param_seq;
+         };
+
+         typedef parser<T> parser_t;
+         typedef std::vector<function_prototype_t> function_definition_list_t;
+
+         type_checker(parser_t& p,
+                      const std::string& func_name,
+                      const std::string& func_prototypes,
+                      const return_type_t default_return_type)
+         : invalid_state_(true),
+           parser_(p),
+           function_name_(func_name),
+           default_return_type_(default_return_type)
+         {
+            parse_function_prototypes(func_prototypes);
+         }
+
+         void set_default_return_type(const std::string& return_type)
+         {
+            default_return_type_ = return_type;
+         }
+
+         bool verify(const std::string& param_seq, std::size_t& pseq_index)
+         {
+            if (function_definition_list_.empty())
+               return true;
+
+            std::vector<std::pair<std::size_t,char> > error_list;
+
+            for (std::size_t i = 0; i < function_definition_list_.size(); ++i)
+            {
+               details::char_t diff_value = 0;
+               std::size_t     diff_index = 0;
+
+               const bool result = details::sequence_match(function_definition_list_[i].param_seq,
+                                                           param_seq,
+                                                           diff_index, diff_value);
+
+              if (result)
+              {
+                 pseq_index = i;
+                 return true;
+              }
+              else
+                 error_list.push_back(std::make_pair(diff_index, diff_value));
+            }
+
+            if (1 == error_list.size())
+            {
+               parser_.
+                  set_error(
+                     make_error(parser_error::e_syntax,
+                                parser_.current_token(),
+                                "ERR117 - Failed parameter type check for function '" + function_name_ + "', "
+                                "Expected '" + function_definition_list_[0].param_seq +
+                                "'  call set: '" + param_seq + "'",
+                                exprtk_error_location));
+            }
+            else
+            {
+               // find first with largest diff_index;
+               std::size_t max_diff_index = 0;
+
+               for (std::size_t i = 1; i < error_list.size(); ++i)
+               {
+                  if (error_list[i].first > error_list[max_diff_index].first)
+                  {
+                     max_diff_index = i;
+                  }
+               }
+
+               parser_.
+                  set_error(
+                     make_error(parser_error::e_syntax,
+                                parser_.current_token(),
+                                "ERR118 - Failed parameter type check for function '" + function_name_ + "', "
+                                "Best match: '" + function_definition_list_[max_diff_index].param_seq +
+                                "'  call set: '" + param_seq + "'",
+                                exprtk_error_location));
+            }
+
+            return false;
+         }
+
+         std::size_t paramseq_count() const
+         {
+            return function_definition_list_.size();
+         }
+
+         std::string paramseq(const std::size_t& index) const
+         {
+            return function_definition_list_[index].param_seq;
+         }
+
+         return_type_t return_type(const std::size_t& index) const
+         {
+            return function_definition_list_[index].return_type;
+         }
+
+         bool invalid() const
+         {
+            return !invalid_state_;
+         }
+
+         bool allow_zero_parameters() const
+         {
+
+            for (std::size_t i = 0; i < function_definition_list_.size(); ++i)
+            {
+               if (std::string::npos != function_definition_list_[i].param_seq.find("Z"))
+               {
+                  return true;
+               }
+            }
+
+            return false;
+         }
+
+      private:
+
+         std::vector<std::string> split_param_seq(const std::string& param_seq, const details::char_t delimiter = '|') const
+         {
+             std::string::const_iterator current_begin = param_seq.begin();
+             std::string::const_iterator iter          = param_seq.begin();
+
+             std::vector<std::string> result;
+
+             while (iter != param_seq.end())
+             {
+                 if (*iter == delimiter)
+                 {
+                     result.push_back(std::string(current_begin, iter));
+                     current_begin = ++iter;
+                 }
+                 else
+                     ++iter;
+             }
+
+             if (current_begin != iter)
+             {
+                 result.push_back(std::string(current_begin, iter));
+             }
+
+             return result;
+         }
+
+         inline bool is_valid_token(std::string param_seq,
+                                    function_prototype_t& funcproto) const
+         {
+            // Determine return type
+            funcproto.return_type = default_return_type_;
+
+            if (param_seq.size() > 2)
+            {
+               if (':' == param_seq[1])
+               {
+                  // Note: Only overloaded igeneric functions can have return
+                  // type definitions.
+                  if (type_checker::e_overload != default_return_type_)
+                     return false;
+
+                  switch (param_seq[0])
+                  {
+                     case 'T' : funcproto.return_type = type_checker::e_numeric;
+                                break;
+
+                     case 'S' : funcproto.return_type = type_checker::e_string;
+                                break;
+
+                     default  : return false;
+                  }
+
+                  param_seq.erase(0,2);
+               }
+            }
+
+            if (
+                 (std::string::npos != param_seq.find("?*")) ||
+                 (std::string::npos != param_seq.find("**"))
+               )
+            {
+               return false;
+            }
+            else if (
+                      (std::string::npos == param_seq.find_first_not_of("STV*?|")) ||
+                      ("Z" == param_seq)
+                    )
+            {
+               funcproto.param_seq = param_seq;
+               return true;
+            }
+
+            return false;
+         }
+
+         void parse_function_prototypes(const std::string& func_prototypes)
+         {
+            if (func_prototypes.empty())
+               return;
+
+            std::vector<std::string> param_seq_list = split_param_seq(func_prototypes);
+
+            typedef std::map<std::string,std::size_t> param_seq_map_t;
+            param_seq_map_t param_seq_map;
+
+            for (std::size_t i = 0; i < param_seq_list.size(); ++i)
+            {
+               function_prototype_t func_proto;
+
+               if (!is_valid_token(param_seq_list[i], func_proto))
+               {
+                  invalid_state_ = false;
+
+                  parser_.
+                     set_error(
+                        make_error(parser_error::e_syntax,
+                                   parser_.current_token(),
+                                   "ERR119 - Invalid parameter sequence of '" + param_seq_list[i] +
+                                   "' for function: " + function_name_,
+                                   exprtk_error_location));
+                  return;
+               }
+
+               param_seq_map_t::const_iterator seq_itr = param_seq_map.find(param_seq_list[i]);
+
+               if (param_seq_map.end() != seq_itr)
+               {
+                  invalid_state_ = false;
+
+                  parser_.
+                     set_error(
+                        make_error(parser_error::e_syntax,
+                                   parser_.current_token(),
+                                   "ERR120 - Function '" + function_name_ + "' has a parameter sequence conflict between " +
+                                   "pseq_idx[" + details::to_str(seq_itr->second) + "] and" +
+                                   "pseq_idx[" + details::to_str(i) + "] " +
+                                   "param seq: " + param_seq_list[i],
+                                   exprtk_error_location));
+                  return;
+               }
+
+               function_definition_list_.push_back(func_proto);
+            }
+         }
+
+         type_checker(const type_checker&);
+         type_checker& operator=(const type_checker&);
+
+         bool invalid_state_;
+         parser_t& parser_;
+         std::string function_name_;
+         const return_type_t default_return_type_;
+         function_definition_list_t function_definition_list_;
+      };
+
+      inline expression_node_ptr parse_generic_function_call(igeneric_function<T>* function, const std::string& function_name)
+      {
+         std::vector<expression_node_ptr> arg_list;
+
+         scoped_vec_delete<expression_node_t> sdd((*this),arg_list);
+
+         next_token();
+
+         std::string param_type_list;
+
+         type_checker tc((*this), function_name, function->parameter_sequence, type_checker::e_string);
+
+         if (tc.invalid())
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR121 - Type checker instantiation failure for generic function: " + function_name,
+                          exprtk_error_location));
+
+            return error_node();
+         }
+
+         if (token_is(token_t::e_lbracket))
+         {
+            if (token_is(token_t::e_rbracket))
+            {
+               if (
+                    !function->allow_zero_parameters() &&
+                    !tc       .allow_zero_parameters()
+                  )
+               {
+                  set_error(
+                     make_error(parser_error::e_syntax,
+                                current_token(),
+                                "ERR122 - Zero parameter call to generic function: "
+                                + function_name + " not allowed",
+                                exprtk_error_location));
+
+                  return error_node();
+               }
+            }
+            else
+            {
+               for ( ; ; )
+               {
+                  expression_node_ptr arg = parse_expression();
+
+                  if (0 == arg)
+                     return error_node();
+
+                  if (is_ivector_node(arg))
+                     param_type_list += 'V';
+                  else if (is_generally_string_node(arg))
+                     param_type_list += 'S';
+                  else // Everything else is assumed to be a scalar returning expression
+                     param_type_list += 'T';
+
+                  arg_list.push_back(arg);
+
+                  if (token_is(token_t::e_rbracket))
+                     break;
+                  else if (!token_is(token_t::e_comma))
+                  {
+                     set_error(
+                        make_error(parser_error::e_syntax,
+                                   current_token(),
+                                   "ERR123 - Expected ',' for call to generic function: " + function_name,
+                                   exprtk_error_location));
+
+                     return error_node();
+                  }
+               }
+            }
+         }
+         else if (
+                   !function->parameter_sequence.empty() &&
+                   function->allow_zero_parameters    () &&
+                   !tc      .allow_zero_parameters    ()
+                 )
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR124 - Zero parameter call to generic function: "
+                          + function_name + " not allowed",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+
+         std::size_t param_seq_index = 0;
+
+         if (
+              state_.type_check_enabled &&
+              !tc.verify(param_type_list, param_seq_index)
+            )
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR125 - Invalid input parameter sequence for call to generic function: " + function_name,
+                          exprtk_error_location));
+
+            return error_node();
+         }
+
+         expression_node_ptr result = error_node();
+
+         if (tc.paramseq_count() <= 1)
+            result = expression_generator_
+                       .generic_function_call(function, arg_list);
+         else
+            result = expression_generator_
+                       .generic_function_call(function, arg_list, param_seq_index);
+
+         sdd.delete_ptr = (0 == result);
+
+         return result;
+      }
+
+      inline bool parse_igeneric_function_params(std::string& param_type_list,
+                                                 std::vector<expression_node_ptr>& arg_list,
+                                                 const std::string& function_name,
+                                                 igeneric_function<T>* function,
+                                                 const type_checker& tc)
+      {
+         if (token_is(token_t::e_lbracket))
+         {
+            if (token_is(token_t::e_rbracket))
+            {
+               if (
+                    !function->allow_zero_parameters() &&
+                    !tc       .allow_zero_parameters()
+                  )
+               {
+                  set_error(
+                     make_error(parser_error::e_syntax,
+                                current_token(),
+                                "ERR126 - Zero parameter call to generic function: "
+                                + function_name + " not allowed",
+                                exprtk_error_location));
+
+                  return false;
+               }
+            }
+            else
+            {
+               for ( ; ; )
+               {
+                  expression_node_ptr arg = parse_expression();
+
+                  if (0 == arg)
+                     return false;
+
+                  if (is_ivector_node(arg))
+                     param_type_list += 'V';
+                  else if (is_generally_string_node(arg))
+                     param_type_list += 'S';
+                  else // Everything else is a scalar returning expression
+                     param_type_list += 'T';
+
+                  arg_list.push_back(arg);
+
+                  if (token_is(token_t::e_rbracket))
+                     break;
+                  else if (!token_is(token_t::e_comma))
+                  {
+                     set_error(
+                        make_error(parser_error::e_syntax,
+                                   current_token(),
+                                   "ERR127 - Expected ',' for call to string function: " + function_name,
+                                   exprtk_error_location));
+
+                     return false;
+                  }
+               }
+            }
+
+            return true;
+         }
+         else
+            return false;
+      }
+
+      #ifndef exprtk_disable_string_capabilities
+      inline expression_node_ptr parse_string_function_call(igeneric_function<T>* function, const std::string& function_name)
+      {
+         // Move pass the function name
+         next_token();
+
+         std::string param_type_list;
+
+         type_checker tc((*this), function_name, function->parameter_sequence, type_checker::e_string);
+
+         if (
+              (!function->parameter_sequence.empty()) &&
+              (0 == tc.paramseq_count())
+            )
+         {
+            return error_node();
+         }
+
+         std::vector<expression_node_ptr> arg_list;
+         scoped_vec_delete<expression_node_t> sdd((*this),arg_list);
+
+         if (!parse_igeneric_function_params(param_type_list, arg_list, function_name, function, tc))
+         {
+            return error_node();
+         }
+
+         std::size_t param_seq_index = 0;
+
+         if (!tc.verify(param_type_list, param_seq_index))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR128 - Invalid input parameter sequence for call to string function: " + function_name,
+                          exprtk_error_location));
+
+            return error_node();
+         }
+
+         expression_node_ptr result = error_node();
+
+         if (tc.paramseq_count() <= 1)
+            result = expression_generator_
+                       .string_function_call(function, arg_list);
+         else
+            result = expression_generator_
+                       .string_function_call(function, arg_list, param_seq_index);
+
+         sdd.delete_ptr = (0 == result);
+
+         return result;
+      }
+
+      inline expression_node_ptr parse_overload_function_call(igeneric_function<T>* function, const std::string& function_name)
+      {
+         // Move pass the function name
+         next_token();
+
+         std::string param_type_list;
+
+         type_checker tc((*this), function_name, function->parameter_sequence, type_checker::e_overload);
+
+         if (
+              (!function->parameter_sequence.empty()) &&
+              (0 == tc.paramseq_count())
+            )
+         {
+            return error_node();
+         }
+
+         std::vector<expression_node_ptr> arg_list;
+         scoped_vec_delete<expression_node_t> sdd((*this),arg_list);
+
+         if (!parse_igeneric_function_params(param_type_list, arg_list, function_name, function, tc))
+         {
+            return error_node();
+         }
+
+         std::size_t param_seq_index = 0;
+
+         if (!tc.verify(param_type_list, param_seq_index))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR129 - Invalid input parameter sequence for call to overloaded function: " + function_name,
+                          exprtk_error_location));
+
+            return error_node();
+         }
+
+         expression_node_ptr result = error_node();
+
+         if (type_checker::e_numeric == tc.return_type(param_seq_index))
+         {
+            if (tc.paramseq_count() <= 1)
+               result = expression_generator_
+                          .generic_function_call(function, arg_list);
+            else
+               result = expression_generator_
+                          .generic_function_call(function, arg_list, param_seq_index);
+         }
+         else if (type_checker::e_string == tc.return_type(param_seq_index))
+         {
+            if (tc.paramseq_count() <= 1)
+               result = expression_generator_
+                          .string_function_call(function, arg_list);
+            else
+               result = expression_generator_
+                          .string_function_call(function, arg_list, param_seq_index);
+         }
+         else
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR130 - Invalid return type for call to overloaded function: " + function_name,
+                          exprtk_error_location));
+         }
+
+         sdd.delete_ptr = (0 == result);
+         return result;
+      }
+      #endif
+
+      template <typename Type, std::size_t NumberOfParameters>
+      struct parse_special_function_impl
+      {
+         static inline expression_node_ptr process(parser<Type>& p, const details::operator_type opt_type, const std::string& sf_name)
+         {
+            expression_node_ptr branch[NumberOfParameters];
+            expression_node_ptr result = error_node();
+
+            std::fill_n(branch,NumberOfParameters,reinterpret_cast<expression_node_ptr>(0));
+
+            scoped_delete<expression_node_t,NumberOfParameters> sd(p,branch);
+
+            p.next_token();
+
+            if (!p.token_is(token_t::e_lbracket))
+            {
+               p.set_error(
+                    make_error(parser_error::e_syntax,
+                               p.current_token(),
+                               "ERR131 - Expected '(' for special function '" + sf_name + "'",
+                               exprtk_error_location));
+
+               return error_node();
+            }
+
+            for (std::size_t i = 0; i < NumberOfParameters; ++i)
+            {
+               branch[i] = p.parse_expression();
+
+               if (0 == branch[i])
+               {
+                  return p.error_node();
+               }
+               else if (i < (NumberOfParameters - 1))
+               {
+                  if (!p.token_is(token_t::e_comma))
+                  {
+                     p.set_error(
+                          make_error(parser_error::e_syntax,
+                                     p.current_token(),
+                                     "ERR132 - Expected ',' before next parameter of special function '" + sf_name + "'",
+                                     exprtk_error_location));
+
+                     return p.error_node();
+                  }
+               }
+            }
+
+            if (!p.token_is(token_t::e_rbracket))
+            {
+               p.set_error(
+                    make_error(parser_error::e_syntax,
+                               p.current_token(),
+                               "ERR133 - Invalid number of parameters for special function '" + sf_name + "'",
+                               exprtk_error_location));
+
+               return p.error_node();
+            }
+            else
+               result = p.expression_generator_.special_function(opt_type,branch);
+
+            sd.delete_ptr = (0 == result);
+
+            return result;
+         }
+      };
+
+      inline expression_node_ptr parse_special_function()
+      {
+         const std::string sf_name = current_token().value;
+
+         // Expect: $fDD(expr0,expr1,expr2) or $fDD(expr0,expr1,expr2,expr3)
+         if (
+              !details::is_digit(sf_name[2]) ||
+              !details::is_digit(sf_name[3])
+            )
+         {
+            set_error(
+               make_error(parser_error::e_token,
+                          current_token(),
+                          "ERR134 - Invalid special function[1]: " + sf_name,
+                          exprtk_error_location));
+
+            return error_node();
+         }
+
+         const int id = (sf_name[2] - '0') * 10 +
+                        (sf_name[3] - '0');
+
+         if (id >= details::e_sffinal)
+         {
+            set_error(
+               make_error(parser_error::e_token,
+                          current_token(),
+                          "ERR135 - Invalid special function[2]: " + sf_name,
+                          exprtk_error_location));
+
+            return error_node();
+         }
+
+         const int sf_3_to_4                   = details::e_sf48;
+         const details::operator_type opt_type = details::operator_type(id + 1000);
+         const std::size_t NumberOfParameters  = (id < (sf_3_to_4 - 1000)) ? 3U : 4U;
+
+         switch (NumberOfParameters)
+         {
+            case 3  : return parse_special_function_impl<T,3>::process((*this), opt_type, sf_name);
+            case 4  : return parse_special_function_impl<T,4>::process((*this), opt_type, sf_name);
+            default : return error_node();
+         }
+      }
+
+      inline expression_node_ptr parse_null_statement()
+      {
+         next_token();
+         return node_allocator_.allocate<details::null_node<T> >();
+      }
+
+      #ifndef exprtk_disable_break_continue
+      inline expression_node_ptr parse_break_statement()
+      {
+         if (state_.parsing_break_stmt)
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR136 - Break call within a break call is not allowed",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+
+         scoped_bool_negator sbn(state_.parsing_break_stmt);
+
+         if (!brkcnt_list_.empty())
+         {
+            next_token();
+
+            brkcnt_list_.front() = true;
+
+            expression_node_ptr return_expr = error_node();
+
+            if (token_is(token_t::e_lsqrbracket))
+            {
+               if (0 == (return_expr = parse_expression()))
+               {
+                  set_error(
+                     make_error(parser_error::e_syntax,
+                                current_token(),
+                                "ERR137 - Failed to parse return expression for 'break' statement",
+                                exprtk_error_location));
+
+                  return error_node();
+               }
+               else if (!token_is(token_t::e_rsqrbracket))
+               {
+                  set_error(
+                     make_error(parser_error::e_syntax,
+                                current_token(),
+                                "ERR138 - Expected ']' at the completion of break's return expression",
+                                exprtk_error_location));
+
+                  free_node(node_allocator_,return_expr);
+
+                  return error_node();
+               }
+            }
+
+            state_.activate_side_effect("parse_break_statement()");
+
+            return node_allocator_.allocate<details::break_node<T> >(return_expr);
+         }
+         else
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR139 - Invalid use of 'break', allowed only in the scope of a loop",
+                          exprtk_error_location));
+         }
+
+         return error_node();
+      }
+
+      inline expression_node_ptr parse_continue_statement()
+      {
+         if (!brkcnt_list_.empty())
+         {
+            next_token();
+
+            brkcnt_list_.front() = true;
+            state_.activate_side_effect("parse_continue_statement()");
+
+            return node_allocator_.allocate<details::continue_node<T> >();
+         }
+         else
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR140 - Invalid use of 'continue', allowed only in the scope of a loop",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+      }
+      #endif
+
+      inline expression_node_ptr parse_define_vector_statement(const std::string& vec_name)
+      {
+         expression_node_ptr size_expr = error_node();
+
+         if (!token_is(token_t::e_lsqrbracket))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR141 - Expected '[' as part of vector size definition",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+         else if (0 == (size_expr = parse_expression()))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR142 - Failed to determine size of vector '" + vec_name + "'",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+         else if (!is_constant_node(size_expr))
+         {
+            free_node(node_allocator_,size_expr);
+
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR143 - Expected a literal number as size of vector '" + vec_name + "'",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+
+         const T vector_size = size_expr->value();
+
+         free_node(node_allocator_,size_expr);
+
+         const T max_vector_size = T(2000000000.0);
+
+         if (
+              (vector_size <= T(0)) ||
+              std::not_equal_to<T>()
+              (T(0),vector_size - details::numeric::trunc(vector_size)) ||
+              (vector_size > max_vector_size)
+            )
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR144 - Invalid vector size. Must be an integer in the range [0,2e9], size: " +
+                          details::to_str(details::numeric::to_int32(vector_size)),
+                          exprtk_error_location));
+
+            return error_node();
+         }
+
+         std::vector<expression_node_ptr> vec_initilizer_list;
+
+         scoped_vec_delete<expression_node_t> svd((*this),vec_initilizer_list);
+
+         bool single_value_initialiser = false;
+         bool vec_to_vec_initialiser   = false;
+         bool null_initialisation      = false;
+
+         if (!token_is(token_t::e_rsqrbracket))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR145 - Expected ']' as part of vector size definition",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+         else if (!token_is(token_t::e_eof))
+         {
+            if (!token_is(token_t::e_assign))
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR146 - Expected ':=' as part of vector definition",
+                             exprtk_error_location));
+
+               return error_node();
+            }
+            else if (token_is(token_t::e_lsqrbracket))
+            {
+               expression_node_ptr initialiser = parse_expression();
+
+               if (0 == initialiser)
+               {
+                  set_error(
+                     make_error(parser_error::e_syntax,
+                                current_token(),
+                                "ERR147 - Failed to parse single vector initialiser",
+                                exprtk_error_location));
+
+                  return error_node();
+               }
+
+               vec_initilizer_list.push_back(initialiser);
+
+               if (!token_is(token_t::e_rsqrbracket))
+               {
+                  set_error(
+                     make_error(parser_error::e_syntax,
+                                current_token(),
+                                "ERR148 - Expected ']' to close single value vector initialiser",
+                                exprtk_error_location));
+
+                  return error_node();
+               }
+
+               single_value_initialiser = true;
+            }
+            else if (!token_is(token_t::e_lcrlbracket))
+            {
+               expression_node_ptr initialiser = error_node();
+
+               // Is this a vector to vector assignment and initialisation?
+               if (token_t::e_symbol == current_token().type)
+               {
+                  // Is it a locally defined vector?
+                  scope_element& se = sem_.get_active_element(current_token().value);
+
+                  if (scope_element::e_vector == se.type)
+                  {
+                     if (0 != (initialiser = parse_expression()))
+                        vec_initilizer_list.push_back(initialiser);
+                     else
+                        return error_node();
+                  }
+                  // Are we dealing with a user defined vector?
+                  else if (symtab_store_.is_vector(current_token().value))
+                  {
+                     lodge_symbol(current_token().value, e_st_vector);
+
+                     if (0 != (initialiser = parse_expression()))
+                        vec_initilizer_list.push_back(initialiser);
+                     else
+                        return error_node();
+                  }
+                  // Are we dealing with a null initialisation vector definition?
+                  else if (token_is(token_t::e_symbol,"null"))
+                     null_initialisation = true;
+               }
+
+               if (!null_initialisation)
+               {
+                  if (0 == initialiser)
+                  {
+                     set_error(
+                        make_error(parser_error::e_syntax,
+                                   current_token(),
+                                   "ERR149 - Expected '{' as part of vector initialiser list",
+                                   exprtk_error_location));
+
+                     return error_node();
+                  }
+                  else
+                     vec_to_vec_initialiser = true;
+               }
+            }
+            else if (!token_is(token_t::e_rcrlbracket))
+            {
+               for ( ; ; )
+               {
+                  expression_node_ptr initialiser = parse_expression();
+
+                  if (0 == initialiser)
+                  {
+                     set_error(
+                        make_error(parser_error::e_syntax,
+                                   current_token(),
+                                   "ERR150 - Expected '{' as part of vector initialiser list",
+                                   exprtk_error_location));
+
+                     return error_node();
+                  }
+                  else
+                     vec_initilizer_list.push_back(initialiser);
+
+                  if (token_is(token_t::e_rcrlbracket))
+                     break;
+
+                  const bool is_next_close = peek_token_is(token_t::e_rcrlbracket);
+
+                  if (!token_is(token_t::e_comma) && is_next_close)
+                  {
+                     set_error(
+                        make_error(parser_error::e_syntax,
+                                   current_token(),
+                                   "ERR151 - Expected ',' between vector initialisers",
+                                   exprtk_error_location));
+
+                     return error_node();
+                  }
+
+                  if (token_is(token_t::e_rcrlbracket))
+                     break;
+               }
+            }
+
+            if (
+                 !token_is(token_t::e_rbracket   , prsrhlpr_t::e_hold) &&
+                 !token_is(token_t::e_rcrlbracket, prsrhlpr_t::e_hold) &&
+                 !token_is(token_t::e_rsqrbracket, prsrhlpr_t::e_hold)
+               )
+            {
+               if (!token_is(token_t::e_eof))
+               {
+                  set_error(
+                     make_error(parser_error::e_syntax,
+                                current_token(),
+                                "ERR152 - Expected ';' at end of vector definition",
+                                exprtk_error_location));
+
+                  return error_node();
+               }
+            }
+
+            if (vec_initilizer_list.size() > vector_size)
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR153 - Initialiser list larger than the number of elements in the vector: '" + vec_name + "'",
+                             exprtk_error_location));
+
+               return error_node();
+            }
+         }
+
+         typename symbol_table_t::vector_holder_ptr vec_holder = typename symbol_table_t::vector_holder_ptr(0);
+
+         const std::size_t vec_size = static_cast<std::size_t>(details::numeric::to_int32(vector_size));
+
+         scope_element& se = sem_.get_element(vec_name);
+
+         if (se.name == vec_name)
+         {
+            if (se.active)
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR154 - Illegal redefinition of local vector: '" + vec_name + "'",
+                             exprtk_error_location));
+
+               return error_node();
+            }
+            else if (
+                      (se.size == vec_size) &&
+                      (scope_element::e_vector == se.type)
+                    )
+            {
+               vec_holder = se.vec_node;
+               se.active  = true;
+               se.depth   = state_.scope_depth;
+               se.ref_count++;
+            }
+         }
+
+         if (0 == vec_holder)
+         {
+            scope_element nse;
+            nse.name      = vec_name;
+            nse.active    = true;
+            nse.ref_count = 1;
+            nse.type      = scope_element::e_vector;
+            nse.depth     = state_.scope_depth;
+            nse.size      = vec_size;
+            nse.data      = new T[vec_size];
+            nse.vec_node  = new typename scope_element::vector_holder_t((T*)(nse.data),nse.size);
+
+            if (!sem_.add_element(nse))
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR155 - Failed to add new local vector '" + vec_name + "' to SEM",
+                             exprtk_error_location));
+
+               sem_.free_element(nse);
+
+               return error_node();
+            }
+
+            vec_holder = nse.vec_node;
+
+            exprtk_debug(("parse_define_vector_statement() - INFO - Added new local vector: %s[%d]\n",
+                          nse.name.c_str(),
+                          static_cast<int>(nse.size)));
+         }
+
+         state_.activate_side_effect("parse_define_vector_statement()");
+
+         lodge_symbol(vec_name, e_st_local_vector);
+
+         expression_node_ptr result = error_node();
+
+         if (null_initialisation)
+            result = expression_generator_(T(0.0));
+         else if (vec_to_vec_initialiser)
+         {
+            expression_node_ptr vec_node = node_allocator_.allocate<vector_node_t>(vec_holder);
+
+            result = expression_generator_(
+                        details::e_assign,
+                        vec_node,
+                        vec_initilizer_list[0]);
+         }
+         else
+            result = node_allocator_
+                        .allocate<details::vector_assignment_node<T> >(
+                           (*vec_holder)[0],
+                           vec_size,
+                           vec_initilizer_list,
+                           single_value_initialiser);
+
+         svd.delete_ptr = (0 == result);
+
+         return result;
+      }
+
+      #ifndef exprtk_disable_string_capabilities
+      inline expression_node_ptr parse_define_string_statement(const std::string& str_name, expression_node_ptr initialisation_expression)
+      {
+         stringvar_node_t* str_node = reinterpret_cast<stringvar_node_t*>(0);
+
+         scope_element& se = sem_.get_element(str_name);
+
+         if (se.name == str_name)
+         {
+            if (se.active)
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR156 - Illegal redefinition of local variable: '" + str_name + "'",
+                             exprtk_error_location));
+
+               free_node(node_allocator_,initialisation_expression);
+
+               return error_node();
+            }
+            else if (scope_element::e_string == se.type)
+            {
+               str_node  = se.str_node;
+               se.active = true;
+               se.depth  = state_.scope_depth;
+               se.ref_count++;
+            }
+         }
+
+         if (0 == str_node)
+         {
+            scope_element nse;
+            nse.name      = str_name;
+            nse.active    = true;
+            nse.ref_count = 1;
+            nse.type      = scope_element::e_string;
+            nse.depth     = state_.scope_depth;
+            nse.data      = new std::string;
+            nse.str_node  = new stringvar_node_t(*(std::string*)(nse.data));
+
+            if (!sem_.add_element(nse))
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR157 - Failed to add new local string variable '" + str_name + "' to SEM",
+                             exprtk_error_location));
+
+               free_node(node_allocator_,initialisation_expression);
+
+               sem_.free_element(nse);
+
+               return error_node();
+            }
+
+            str_node = nse.str_node;
+
+            exprtk_debug(("parse_define_string_statement() - INFO - Added new local string variable: %s\n",nse.name.c_str()));
+         }
+
+         lodge_symbol(str_name, e_st_local_string);
+
+         state_.activate_side_effect("parse_define_string_statement()");
+
+         expression_node_ptr branch[2] = {0};
+
+         branch[0] = str_node;
+         branch[1] = initialisation_expression;
+
+         return expression_generator_(details::e_assign,branch);
+      }
+      #else
+      inline expression_node_ptr parse_define_string_statement(const std::string&, expression_node_ptr)
+      {
+         return error_node();
+      }
+      #endif
+
+      inline bool local_variable_is_shadowed(const std::string& symbol)
+      {
+         const scope_element& se = sem_.get_element(symbol);
+         return (se.name == symbol) && se.active;
+      }
+
+      inline expression_node_ptr parse_define_var_statement()
+      {
+         if (settings_.vardef_disabled())
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR158 - Illegal variable definition",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+         else if (!details::imatch(current_token().value,"var"))
+         {
+            return error_node();
+         }
+         else
+            next_token();
+
+         const std::string var_name = current_token().value;
+
+         expression_node_ptr initialisation_expression = error_node();
+
+         if (!token_is(token_t::e_symbol))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR159 - Expected a symbol for variable definition",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+         else if (details::is_reserved_symbol(var_name))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR160 - Illegal redefinition of reserved keyword: '" + var_name + "'",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+         else if (symtab_store_.symbol_exists(var_name))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR161 - Illegal redefinition of variable '" + var_name + "'",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+         else if (local_variable_is_shadowed(var_name))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR162 - Illegal redefinition of local variable: '" + var_name + "'",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+         else if (token_is(token_t::e_lsqrbracket,prsrhlpr_t::e_hold))
+         {
+            return parse_define_vector_statement(var_name);
+         }
+         else if (token_is(token_t::e_lcrlbracket,prsrhlpr_t::e_hold))
+         {
+            return parse_uninitialised_var_statement(var_name);
+         }
+         else if (token_is(token_t::e_assign))
+         {
+            if (0 == (initialisation_expression = parse_expression()))
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR163 - Failed to parse initialisation expression",
+                             exprtk_error_location));
+
+               return error_node();
+            }
+         }
+
+         if (
+              !token_is(token_t::e_rbracket   , prsrhlpr_t::e_hold) &&
+              !token_is(token_t::e_rcrlbracket, prsrhlpr_t::e_hold) &&
+              !token_is(token_t::e_rsqrbracket, prsrhlpr_t::e_hold)
+            )
+         {
+            if (!token_is(token_t::e_eof,prsrhlpr_t::e_hold))
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR164 - Expected ';' after variable definition",
+                             exprtk_error_location));
+
+               free_node(node_allocator_,initialisation_expression);
+
+               return error_node();
+            }
+         }
+
+         if (
+              (0 != initialisation_expression) &&
+              details::is_generally_string_node(initialisation_expression)
+            )
+         {
+            return parse_define_string_statement(var_name,initialisation_expression);
+         }
+
+         expression_node_ptr var_node = reinterpret_cast<expression_node_ptr>(0);
+
+         scope_element& se = sem_.get_element(var_name);
+
+         if (se.name == var_name)
+         {
+            if (se.active)
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR165 - Illegal redefinition of local variable: '" + var_name + "'",
+                             exprtk_error_location));
+
+               free_node(node_allocator_, initialisation_expression);
+
+               return error_node();
+            }
+            else if (scope_element::e_variable == se.type)
+            {
+               var_node  = se.var_node;
+               se.active = true;
+               se.depth  = state_.scope_depth;
+               se.ref_count++;
+            }
+         }
+
+         if (0 == var_node)
+         {
+            scope_element nse;
+            nse.name      = var_name;
+            nse.active    = true;
+            nse.ref_count = 1;
+            nse.type      = scope_element::e_variable;
+            nse.depth     = state_.scope_depth;
+            nse.data      = new T(T(0));
+            nse.var_node  = node_allocator_.allocate<variable_node_t>(*(T*)(nse.data));
+
+            if (!sem_.add_element(nse))
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR166 - Failed to add new local variable '" + var_name + "' to SEM",
+                             exprtk_error_location));
+
+               free_node(node_allocator_, initialisation_expression);
+
+               sem_.free_element(nse);
+
+               return error_node();
+            }
+
+            var_node = nse.var_node;
+
+            exprtk_debug(("parse_define_var_statement() - INFO - Added new local variable: %s\n",nse.name.c_str()));
+         }
+
+         state_.activate_side_effect("parse_define_var_statement()");
+
+         lodge_symbol(var_name, e_st_local_variable);
+
+         expression_node_ptr branch[2] = {0};
+
+         branch[0] = var_node;
+         branch[1] = initialisation_expression ? initialisation_expression : expression_generator_(T(0));
+
+         return expression_generator_(details::e_assign,branch);
+      }
+
+      inline expression_node_ptr parse_uninitialised_var_statement(const std::string& var_name)
+      {
+         if (
+              !token_is(token_t::e_lcrlbracket) ||
+              !token_is(token_t::e_rcrlbracket)
+            )
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR167 - Expected a '{}' for uninitialised var definition",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+         else if (!token_is(token_t::e_eof,prsrhlpr_t::e_hold))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR168 - Expected ';' after uninitialised variable definition",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+
+         expression_node_ptr var_node = reinterpret_cast<expression_node_ptr>(0);
+
+         scope_element& se = sem_.get_element(var_name);
+
+         if (se.name == var_name)
+         {
+            if (se.active)
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR169 - Illegal redefinition of local variable: '" + var_name + "'",
+                             exprtk_error_location));
+
+               return error_node();
+            }
+            else if (scope_element::e_variable == se.type)
+            {
+               var_node  = se.var_node;
+               se.active = true;
+               se.ref_count++;
+            }
+         }
+
+         if (0 == var_node)
+         {
+            scope_element nse;
+            nse.name      = var_name;
+            nse.active    = true;
+            nse.ref_count = 1;
+            nse.type      = scope_element::e_variable;
+            nse.depth     = state_.scope_depth;
+            nse.ip_index  = sem_.next_ip_index();
+            nse.data      = new T(T(0));
+            nse.var_node  = node_allocator_.allocate<variable_node_t>(*(T*)(nse.data));
+
+            if (!sem_.add_element(nse))
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR170 - Failed to add new local variable '" + var_name + "' to SEM",
+                             exprtk_error_location));
+
+               sem_.free_element(nse);
+
+               return error_node();
+            }
+
+            exprtk_debug(("parse_uninitialised_var_statement() - INFO - Added new local variable: %s\n",
+                          nse.name.c_str()));
+         }
+
+         lodge_symbol(var_name, e_st_local_variable);
+
+         state_.activate_side_effect("parse_uninitialised_var_statement()");
+
+         return expression_generator_(T(0));
+      }
+
+      inline expression_node_ptr parse_swap_statement()
+      {
+         if (!details::imatch(current_token().value,"swap"))
+         {
+            return error_node();
+         }
+         else
+            next_token();
+
+         if (!token_is(token_t::e_lbracket))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR171 - Expected '(' at start of swap statement",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+
+         expression_node_ptr variable0 = error_node();
+         expression_node_ptr variable1 = error_node();
+
+         bool variable0_generated = false;
+         bool variable1_generated = false;
+
+         const std::string var0_name = current_token().value;
+
+         if (!token_is(token_t::e_symbol,prsrhlpr_t::e_hold))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR172 - Expected a symbol for variable or vector element definition",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+         else if (peek_token_is(token_t::e_lsqrbracket))
+         {
+            if (0 == (variable0 = parse_vector()))
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR173 - First parameter to swap is an invalid vector element: '" + var0_name + "'",
+                             exprtk_error_location));
+
+               return error_node();
+            }
+
+            variable0_generated = true;
+         }
+         else
+         {
+            if (symtab_store_.is_variable(var0_name))
+            {
+               variable0 = symtab_store_.get_variable(var0_name);
+            }
+
+            scope_element& se = sem_.get_element(var0_name);
+
+            if (
+                 (se.active)            &&
+                 (se.name == var0_name) &&
+                 (scope_element::e_variable == se.type)
+               )
+            {
+               variable0 = se.var_node;
+            }
+
+            lodge_symbol(var0_name, e_st_variable);
+
+            if (0 == variable0)
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR174 - First parameter to swap is an invalid variable: '" + var0_name + "'",
+                             exprtk_error_location));
+
+               return error_node();
+            }
+            else
+               next_token();
+         }
+
+         if (!token_is(token_t::e_comma))
+         {
+            set_error(
+                make_error(parser_error::e_syntax,
+                           current_token(),
+                           "ERR175 - Expected ',' between parameters to swap",
+                           exprtk_error_location));
+
+            if (variable0_generated)
+            {
+               free_node(node_allocator_,variable0);
+            }
+
+            return error_node();
+         }
+
+         const std::string var1_name = current_token().value;
+
+         if (!token_is(token_t::e_symbol,prsrhlpr_t::e_hold))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR176 - Expected a symbol for variable or vector element definition",
+                          exprtk_error_location));
+
+            if (variable0_generated)
+            {
+               free_node(node_allocator_,variable0);
+            }
+
+            return error_node();
+         }
+         else if (peek_token_is(token_t::e_lsqrbracket))
+         {
+            if (0 == (variable1 = parse_vector()))
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR177 - Second parameter to swap is an invalid vector element: '" + var1_name + "'",
+                             exprtk_error_location));
+
+               if (variable0_generated)
+               {
+                  free_node(node_allocator_,variable0);
+               }
+
+               return error_node();
+            }
+
+            variable1_generated = true;
+         }
+         else
+         {
+            if (symtab_store_.is_variable(var1_name))
+            {
+               variable1 = symtab_store_.get_variable(var1_name);
+            }
+
+            scope_element& se = sem_.get_element(var1_name);
+
+            if (
+                 (se.active) &&
+                 (se.name == var1_name) &&
+                 (scope_element::e_variable == se.type)
+               )
+            {
+               variable1 = se.var_node;
+            }
+
+            lodge_symbol(var1_name, e_st_variable);
+
+            if (0 == variable1)
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR178 - Second parameter to swap is an invalid variable: '" + var1_name + "'",
+                             exprtk_error_location));
+
+               if (variable0_generated)
+               {
+                  free_node(node_allocator_,variable0);
+               }
+
+               return error_node();
+            }
+            else
+               next_token();
+         }
+
+         if (!token_is(token_t::e_rbracket))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR179 - Expected ')' at end of swap statement",
+                          exprtk_error_location));
+
+            if (variable0_generated)
+            {
+               free_node(node_allocator_,variable0);
+            }
+
+            if (variable1_generated)
+            {
+               free_node(node_allocator_,variable1);
+            }
+
+            return error_node();
+         }
+
+         typedef details::variable_node<T>* variable_node_ptr;
+
+         variable_node_ptr v0 = variable_node_ptr(0);
+         variable_node_ptr v1 = variable_node_ptr(0);
+
+         expression_node_ptr result = error_node();
+
+         if (
+              (0 != (v0 = dynamic_cast<variable_node_ptr>(variable0))) &&
+              (0 != (v1 = dynamic_cast<variable_node_ptr>(variable1)))
+            )
+         {
+            result = node_allocator_.allocate<details::swap_node<T> >(v0, v1);
+
+            if (variable0_generated)
+            {
+               free_node(node_allocator_,variable0);
+            }
+
+            if (variable1_generated)
+            {
+               free_node(node_allocator_,variable1);
+            }
+         }
+         else
+            result = node_allocator_.allocate<details::swap_generic_node<T> >
+                        (variable0, variable1);
+
+         state_.activate_side_effect("parse_swap_statement()");
+
+         return result;
+      }
+
+      #ifndef exprtk_disable_return_statement
+      inline expression_node_ptr parse_return_statement()
+      {
+         if (state_.parsing_return_stmt)
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR180 - Return call within a return call is not allowed",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+
+         scoped_bool_negator sbn(state_.parsing_return_stmt);
+
+         std::vector<expression_node_ptr> arg_list;
+
+         scoped_vec_delete<expression_node_t> sdd((*this),arg_list);
+
+         if (!details::imatch(current_token().value,"return"))
+         {
+            return error_node();
+         }
+         else
+            next_token();
+
+         if (!token_is(token_t::e_lsqrbracket))
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR181 - Expected '[' at start of return statement",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+         else if (!token_is(token_t::e_rsqrbracket))
+         {
+            for ( ; ; )
+            {
+               expression_node_ptr arg = parse_expression();
+
+               if (0 == arg)
+                  return error_node();
+
+               arg_list.push_back(arg);
+
+               if (token_is(token_t::e_rsqrbracket))
+                  break;
+               else if (!token_is(token_t::e_comma))
+               {
+                  set_error(
+                     make_error(parser_error::e_syntax,
+                                current_token(),
+                                "ERR182 - Expected ',' between values during call to return",
+                                exprtk_error_location));
+
+                  return error_node();
+               }
+            }
+         }
+         else if (settings_.zero_return_disabled())
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR183 - Zero parameter return statement not allowed",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+
+         const lexer::token prev_token = current_token();
+
+         if (token_is(token_t::e_rsqrbracket))
+         {
+            if (!arg_list.empty())
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             prev_token,
+                             "ERR184 - Invalid ']' found during return call",
+                             exprtk_error_location));
+
+               return error_node();
+            }
+         }
+
+         std::string ret_param_type_list;
+
+         for (std::size_t i = 0; i < arg_list.size(); ++i)
+         {
+            if (0 == arg_list[i])
+               return error_node();
+            else if (is_ivector_node(arg_list[i]))
+               ret_param_type_list += 'V';
+            else if (is_generally_string_node(arg_list[i]))
+               ret_param_type_list += 'S';
+            else
+               ret_param_type_list += 'T';
+         }
+
+         dec_.retparam_list_.push_back(ret_param_type_list);
+
+         expression_node_ptr result = expression_generator_.return_call(arg_list);
+
+         sdd.delete_ptr = (0 == result);
+
+         state_.return_stmt_present = true;
+
+         state_.activate_side_effect("parse_return_statement()");
+
+         return result;
+      }
+      #else
+      inline expression_node_ptr parse_return_statement()
+      {
+         return error_node();
+      }
+      #endif
+
+      inline bool post_variable_process(const std::string& symbol)
+      {
+         if (
+              peek_token_is(token_t::e_lbracket   ) ||
+              peek_token_is(token_t::e_lcrlbracket) ||
+              peek_token_is(token_t::e_lsqrbracket)
+            )
+         {
+            if (!settings_.commutative_check_enabled())
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR185 - Invalid sequence of variable '"+ symbol + "' and bracket",
+                             exprtk_error_location));
+
+               return false;
+            }
+
+            lexer().insert_front(token_t::e_mul);
+         }
+
+         return true;
+      }
+
+      inline bool post_bracket_process(const typename token_t::token_type& token, expression_node_ptr& branch)
+      {
+         bool implied_mul = false;
+
+         if (is_generally_string_node(branch))
+            return true;
+
+         const lexer::parser_helper::token_advance_mode hold = prsrhlpr_t::e_hold;
+
+         switch (token)
+         {
+            case token_t::e_lcrlbracket : implied_mul = token_is(token_t::e_lbracket   ,hold) ||
+                                                        token_is(token_t::e_lcrlbracket,hold) ||
+                                                        token_is(token_t::e_lsqrbracket,hold) ;
+                                          break;
+
+            case token_t::e_lbracket    : implied_mul = token_is(token_t::e_lbracket   ,hold) ||
+                                                        token_is(token_t::e_lcrlbracket,hold) ||
+                                                        token_is(token_t::e_lsqrbracket,hold) ;
+                                          break;
+
+            case token_t::e_lsqrbracket : implied_mul = token_is(token_t::e_lbracket   ,hold) ||
+                                                        token_is(token_t::e_lcrlbracket,hold) ||
+                                                        token_is(token_t::e_lsqrbracket,hold) ;
+                                          break;
+
+            default                     : return true;
+         }
+
+         if (implied_mul)
+         {
+            if (!settings_.commutative_check_enabled())
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR186 - Invalid sequence of brackets",
+                             exprtk_error_location));
+
+               return false;
+            }
+            else if (token_t::e_eof != current_token().type)
+            {
+               lexer().insert_front(current_token().type);
+               lexer().insert_front(token_t::e_mul);
+               next_token();
+            }
+         }
+
+         return true;
+      }
+
+      inline expression_node_ptr parse_symtab_symbol()
+      {
+         const std::string symbol = current_token().value;
+
+         // Are we dealing with a variable or a special constant?
+         expression_node_ptr variable = symtab_store_.get_variable(symbol);
+
+         if (variable)
+         {
+            if (symtab_store_.is_constant_node(symbol))
+            {
+               variable = expression_generator_(variable->value());
+            }
+
+            if (!post_variable_process(symbol))
+               return error_node();
+
+            lodge_symbol(symbol, e_st_variable);
+            next_token();
+
+            return variable;
+         }
+
+         // Are we dealing with a locally defined variable, vector or string?
+         if (!sem_.empty())
+         {
+            scope_element& se = sem_.get_active_element(symbol);
+
+            if (se.active && details::imatch(se.name, symbol))
+            {
+               if (scope_element::e_variable == se.type)
+               {
+                  se.active = true;
+                  lodge_symbol(symbol, e_st_local_variable);
+
+                  if (!post_variable_process(symbol))
+                     return error_node();
+
+                  next_token();
+
+                  return se.var_node;
+               }
+               else if (scope_element::e_vector == se.type)
+               {
+                  return parse_vector();
+               }
+               #ifndef exprtk_disable_string_capabilities
+               else if (scope_element::e_string == se.type)
+               {
+                  return parse_string();
+               }
+               #endif
+            }
+         }
+
+         #ifndef exprtk_disable_string_capabilities
+         // Are we dealing with a string variable?
+         if (symtab_store_.is_stringvar(symbol))
+         {
+            return parse_string();
+         }
+         #endif
+
+         {
+            // Are we dealing with a function?
+            ifunction<T>* function = symtab_store_.get_function(symbol);
+
+            if (function)
+            {
+               lodge_symbol(symbol, e_st_function);
+
+               expression_node_ptr func_node =
+                                      parse_function_invocation(function,symbol);
+
+               if (func_node)
+                  return func_node;
+               else
+               {
+                  set_error(
+                     make_error(parser_error::e_syntax,
+                                current_token(),
+                                "ERR187 - Failed to generate node for function: '" + symbol + "'",
+                                exprtk_error_location));
+
+                  return error_node();
+               }
+            }
+         }
+
+         {
+            // Are we dealing with a vararg function?
+            ivararg_function<T>* vararg_function = symtab_store_.get_vararg_function(symbol);
+
+            if (vararg_function)
+            {
+               lodge_symbol(symbol, e_st_function);
+
+               expression_node_ptr vararg_func_node =
+                                      parse_vararg_function_call(vararg_function, symbol);
+
+               if (vararg_func_node)
+                  return vararg_func_node;
+               else
+               {
+                  set_error(
+                     make_error(parser_error::e_syntax,
+                                current_token(),
+                                "ERR188 - Failed to generate node for vararg function: '" + symbol + "'",
+                                exprtk_error_location));
+
+                  return error_node();
+               }
+            }
+         }
+
+         {
+            // Are we dealing with a vararg generic function?
+            igeneric_function<T>* generic_function = symtab_store_.get_generic_function(symbol);
+
+            if (generic_function)
+            {
+               lodge_symbol(symbol, e_st_function);
+
+               expression_node_ptr genericfunc_node =
+                                      parse_generic_function_call(generic_function, symbol);
+
+               if (genericfunc_node)
+                  return genericfunc_node;
+               else
+               {
+                  set_error(
+                     make_error(parser_error::e_syntax,
+                                current_token(),
+                                "ERR189 - Failed to generate node for generic function: '" + symbol + "'",
+                                exprtk_error_location));
+
+                  return error_node();
+               }
+            }
+         }
+
+         #ifndef exprtk_disable_string_capabilities
+         {
+            // Are we dealing with a vararg string returning function?
+            igeneric_function<T>* string_function = symtab_store_.get_string_function(symbol);
+
+            if (string_function)
+            {
+               lodge_symbol(symbol, e_st_function);
+
+               expression_node_ptr stringfunc_node =
+                                      parse_string_function_call(string_function, symbol);
+
+               if (stringfunc_node)
+                  return stringfunc_node;
+               else
+               {
+                  set_error(
+                     make_error(parser_error::e_syntax,
+                                current_token(),
+                                "ERR190 - Failed to generate node for string function: '" + symbol + "'",
+                                exprtk_error_location));
+
+                  return error_node();
+               }
+            }
+         }
+
+         {
+            // Are we dealing with a vararg overloaded scalar/string returning function?
+            igeneric_function<T>* overload_function = symtab_store_.get_overload_function(symbol);
+
+            if (overload_function)
+            {
+               lodge_symbol(symbol, e_st_function);
+
+               expression_node_ptr overloadfunc_node =
+                                      parse_overload_function_call(overload_function, symbol);
+
+               if (overloadfunc_node)
+                  return overloadfunc_node;
+               else
+               {
+                  set_error(
+                     make_error(parser_error::e_syntax,
+                                current_token(),
+                                "ERR191 - Failed to generate node for overload function: '" + symbol + "'",
+                                exprtk_error_location));
+
+                  return error_node();
+               }
+            }
+         }
+         #endif
+
+         // Are we dealing with a vector?
+         if (symtab_store_.is_vector(symbol))
+         {
+            lodge_symbol(symbol, e_st_vector);
+            return parse_vector();
+         }
+
+         if (details::is_reserved_symbol(symbol))
+         {
+               if (
+                    settings_.function_enabled(symbol) ||
+                    !details::is_base_function(symbol)
+                  )
+               {
+                  set_error(
+                     make_error(parser_error::e_syntax,
+                                current_token(),
+                                "ERR192 - Invalid use of reserved symbol '" + symbol + "'",
+                                exprtk_error_location));
+
+                  return error_node();
+               }
+         }
+
+         // Should we handle unknown symbols?
+         if (resolve_unknown_symbol_ && unknown_symbol_resolver_)
+         {
+            if (!(settings_.rsrvd_sym_usr_disabled() && details::is_reserved_symbol(symbol)))
+            {
+               symbol_table_t& symtab = symtab_store_.get_symbol_table();
+
+               std::string error_message;
+
+               if (unknown_symbol_resolver::e_usrmode_default == unknown_symbol_resolver_->mode)
+               {
+                  T default_value = T(0);
+
+                  typename unknown_symbol_resolver::usr_symbol_type usr_symbol_type = unknown_symbol_resolver::e_usr_unknown_type;
+
+                  if (unknown_symbol_resolver_->process(symbol, usr_symbol_type, default_value, error_message))
+                  {
+                     bool create_result = false;
+
+                     switch (usr_symbol_type)
+                     {
+                        case unknown_symbol_resolver::e_usr_variable_type : create_result = symtab.create_variable(symbol, default_value);
+                                                                            break;
+
+                        case unknown_symbol_resolver::e_usr_constant_type : create_result = symtab.add_constant(symbol, default_value);
+                                                                            break;
+
+                        default                                           : create_result = false;
+                     }
+
+                     if (create_result)
+                     {
+                        expression_node_ptr var = symtab_store_.get_variable(symbol);
+
+                        if (var)
+                        {
+                           if (symtab_store_.is_constant_node(symbol))
+                           {
+                              var = expression_generator_(var->value());
+                           }
+
+                           lodge_symbol(symbol, e_st_variable);
+
+                           if (!post_variable_process(symbol))
+                              return error_node();
+
+                           next_token();
+
+                           return var;
+                        }
+                     }
+                  }
+
+                  set_error(
+                     make_error(parser_error::e_symtab,
+                                current_token(),
+                                "ERR193 - Failed to create variable: '" + symbol + "'" +
+                                (error_message.empty() ? "" : " - " + error_message),
+                                exprtk_error_location));
+
+               }
+               else if (unknown_symbol_resolver::e_usrmode_extended == unknown_symbol_resolver_->mode)
+               {
+                  if (unknown_symbol_resolver_->process(symbol, symtab, error_message))
+                  {
+                     expression_node_ptr result = parse_symtab_symbol();
+
+                     if (result)
+                     {
+                        return result;
+                     }
+                  }
+
+                  set_error(
+                     make_error(parser_error::e_symtab,
+                                current_token(),
+                                "ERR194 - Failed to resolve symbol: '" + symbol + "'" +
+                                (error_message.empty() ? "" : " - " + error_message),
+                                exprtk_error_location));
+               }
+
+               return error_node();
+            }
+         }
+
+         set_error(
+            make_error(parser_error::e_syntax,
+                       current_token(),
+                       "ERR195 - Undefined symbol: '" + symbol + "'",
+                       exprtk_error_location));
+
+         return error_node();
+      }
+
+      inline expression_node_ptr parse_symbol()
+      {
+         static const std::string symbol_if       = "if"      ;
+         static const std::string symbol_while    = "while"   ;
+         static const std::string symbol_repeat   = "repeat"  ;
+         static const std::string symbol_for      = "for"     ;
+         static const std::string symbol_switch   = "switch"  ;
+         static const std::string symbol_null     = "null"    ;
+         static const std::string symbol_break    = "break"   ;
+         static const std::string symbol_continue = "continue";
+         static const std::string symbol_var      = "var"     ;
+         static const std::string symbol_swap     = "swap"    ;
+         static const std::string symbol_return   = "return"  ;
+         static const std::string symbol_not      = "not"     ;
+
+         if (valid_vararg_operation(current_token().value))
+         {
+            return parse_vararg_function();
+         }
+         else if (details::imatch(current_token().value, symbol_not))
+         {
+            return parse_not_statement();
+         }
+         else if (valid_base_operation(current_token().value))
+         {
+            return parse_base_operation();
+         }
+         else if (
+                   details::imatch(current_token().value, symbol_if) &&
+                   settings_.control_struct_enabled(current_token().value)
+                 )
+         {
+            return parse_conditional_statement();
+         }
+         else if (
+                   details::imatch(current_token().value, symbol_while) &&
+                   settings_.control_struct_enabled(current_token().value)
+                 )
+         {
+            return parse_while_loop();
+         }
+         else if (
+                   details::imatch(current_token().value, symbol_repeat) &&
+                   settings_.control_struct_enabled(current_token().value)
+                 )
+         {
+            return parse_repeat_until_loop();
+         }
+         else if (
+                   details::imatch(current_token().value, symbol_for) &&
+                   settings_.control_struct_enabled(current_token().value)
+                 )
+         {
+            return parse_for_loop();
+         }
+         else if (
+                   details::imatch(current_token().value, symbol_switch) &&
+                   settings_.control_struct_enabled(current_token().value)
+                 )
+         {
+            return parse_switch_statement();
+         }
+         else if (details::is_valid_sf_symbol(current_token().value))
+         {
+            return parse_special_function();
+         }
+         else if (details::imatch(current_token().value, symbol_null))
+         {
+            return parse_null_statement();
+         }
+         #ifndef exprtk_disable_break_continue
+         else if (details::imatch(current_token().value, symbol_break))
+         {
+            return parse_break_statement();
+         }
+         else if (details::imatch(current_token().value, symbol_continue))
+         {
+            return parse_continue_statement();
+         }
+         #endif
+         else if (details::imatch(current_token().value, symbol_var))
+         {
+            return parse_define_var_statement();
+         }
+         else if (details::imatch(current_token().value, symbol_swap))
+         {
+            return parse_swap_statement();
+         }
+         #ifndef exprtk_disable_return_statement
+         else if (
+                   details::imatch(current_token().value, symbol_return) &&
+                   settings_.control_struct_enabled(current_token().value)
+                 )
+         {
+            return parse_return_statement();
+         }
+         #endif
+         else if (symtab_store_.valid() || !sem_.empty())
+         {
+            return parse_symtab_symbol();
+         }
+         else
+         {
+            set_error(
+               make_error(parser_error::e_symtab,
+                          current_token(),
+                          "ERR196 - Variable or function detected, yet symbol-table is invalid, Symbol: " + current_token().value,
+                          exprtk_error_location));
+
+            return error_node();
+         }
+      }
+
+      inline expression_node_ptr parse_branch(precedence_level precedence = e_level00)
+      {
+         expression_node_ptr branch = error_node();
+
+         if (token_t::e_number == current_token().type)
+         {
+            T numeric_value = T(0);
+
+            if (details::string_to_real(current_token().value, numeric_value))
+            {
+               expression_node_ptr literal_exp = expression_generator_(numeric_value);
+
+               if (0 == literal_exp)
+               {
+                  set_error(
+                     make_error(parser_error::e_numeric,
+                                current_token(),
+                                "ERR197 - Failed generate node for scalar: '" + current_token().value + "'",
+                                exprtk_error_location));
+
+                  return error_node();
+               }
+
+               next_token();
+               branch = literal_exp;
+            }
+            else
+            {
+               set_error(
+                  make_error(parser_error::e_numeric,
+                             current_token(),
+                             "ERR198 - Failed to convert '" + current_token().value + "' to a number",
+                             exprtk_error_location));
+
+               return error_node();
+            }
+         }
+         else if (token_t::e_symbol == current_token().type)
+         {
+            branch = parse_symbol();
+         }
+         #ifndef exprtk_disable_string_capabilities
+         else if (token_t::e_string == current_token().type)
+         {
+            branch = parse_const_string();
+         }
+         #endif
+         else if (token_t::e_lbracket == current_token().type)
+         {
+            next_token();
+
+            if (0 == (branch = parse_expression()))
+               return error_node();
+            else if (!token_is(token_t::e_rbracket))
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR199 - Expected ')' instead of: '" + current_token().value + "'",
+                             exprtk_error_location));
+
+               free_node(node_allocator_,branch);
+
+               return error_node();
+            }
+            else if (!post_bracket_process(token_t::e_lbracket,branch))
+            {
+               free_node(node_allocator_,branch);
+
+               return error_node();
+            }
+         }
+         else if (token_t::e_lsqrbracket == current_token().type)
+         {
+            next_token();
+
+            if (0 == (branch = parse_expression()))
+               return error_node();
+            else if (!token_is(token_t::e_rsqrbracket))
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR200 - Expected ']' instead of: '" + current_token().value + "'",
+                             exprtk_error_location));
+
+               free_node(node_allocator_,branch);
+
+               return error_node();
+            }
+            else if (!post_bracket_process(token_t::e_lsqrbracket,branch))
+            {
+               free_node(node_allocator_,branch);
+
+               return error_node();
+            }
+         }
+         else if (token_t::e_lcrlbracket == current_token().type)
+         {
+            next_token();
+
+            if (0 == (branch = parse_expression()))
+               return error_node();
+            else if (!token_is(token_t::e_rcrlbracket))
+            {
+               set_error(
+                  make_error(parser_error::e_syntax,
+                             current_token(),
+                             "ERR201 - Expected '}' instead of: '" + current_token().value + "'",
+                             exprtk_error_location));
+
+               free_node(node_allocator_,branch);
+
+               return error_node();
+            }
+            else if (!post_bracket_process(token_t::e_lcrlbracket,branch))
+            {
+               free_node(node_allocator_,branch);
+
+               return error_node();
+            }
+         }
+         else if (token_t::e_sub == current_token().type)
+         {
+            next_token();
+            branch = parse_expression(e_level11);
+
+            if (
+                 branch &&
+                 !(
+                    details::is_neg_unary_node    (branch) &&
+                    simplify_unary_negation_branch(branch)
+                  )
+               )
+            {
+               branch = expression_generator_(details::e_neg,branch);
+            }
+         }
+         else if (token_t::e_add == current_token().type)
+         {
+            next_token();
+            branch = parse_expression(e_level13);
+         }
+         else if (token_t::e_eof == current_token().type)
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR202 - Premature end of expression[1]",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+         else
+         {
+            set_error(
+               make_error(parser_error::e_syntax,
+                          current_token(),
+                          "ERR203 - Premature end of expression[2]",
+                          exprtk_error_location));
+
+            return error_node();
+         }
+
+         if (
+              branch                    &&
+              (e_level00 == precedence) &&
+              token_is(token_t::e_ternary,prsrhlpr_t::e_hold)
+            )
+         {
+            branch = parse_ternary_conditional_statement(branch);
+         }
+
+         parse_pending_string_rangesize(branch);
+
+         return branch;
+      }
+
+      template <typename Type>
+      class expression_generator
+      {
+      public:
+
+         typedef details::expression_node<Type>* expression_node_ptr;
+         typedef expression_node_ptr (*synthesize_functor_t)(expression_generator<T>&, const details::operator_type& operation, expression_node_ptr (&branch)[2]);
+         typedef std::map<std::string,synthesize_functor_t> synthesize_map_t;
+         typedef typename exprtk::parser<Type> parser_t;
+         typedef const Type& vtype;
+         typedef const Type  ctype;
+
+         inline void init_synthesize_map()
+         {
+            #ifndef exprtk_disable_enhanced_features
+            synthesize_map_["(v)o(v)"] = synthesize_vov_expression::process;
+            synthesize_map_["(c)o(v)"] = synthesize_cov_expression::process;
+            synthesize_map_["(v)o(c)"] = synthesize_voc_expression::process;
+
+            #define register_synthezier(S)                      \
+            synthesize_map_[S ::node_type::id()] = S ::process; \
+
+            register_synthezier(synthesize_vovov_expression0)
+            register_synthezier(synthesize_vovov_expression1)
+            register_synthezier(synthesize_vovoc_expression0)
+            register_synthezier(synthesize_vovoc_expression1)
+            register_synthezier(synthesize_vocov_expression0)
+            register_synthezier(synthesize_vocov_expression1)
+            register_synthezier(synthesize_covov_expression0)
+            register_synthezier(synthesize_covov_expression1)
+            register_synthezier(synthesize_covoc_expression0)
+            register_synthezier(synthesize_covoc_expression1)
+            register_synthezier(synthesize_cocov_expression1)
+            register_synthezier(synthesize_vococ_expression0)
+
+            register_synthezier(synthesize_vovovov_expression0)
+            register_synthezier(synthesize_vovovoc_expression0)
+            register_synthezier(synthesize_vovocov_expression0)
+            register_synthezier(synthesize_vocovov_expression0)
+            register_synthezier(synthesize_covovov_expression0)
+            register_synthezier(synthesize_covocov_expression0)
+            register_synthezier(synthesize_vocovoc_expression0)
+            register_synthezier(synthesize_covovoc_expression0)
+            register_synthezier(synthesize_vococov_expression0)
+
+            register_synthezier(synthesize_vovovov_expression1)
+            register_synthezier(synthesize_vovovoc_expression1)
+            register_synthezier(synthesize_vovocov_expression1)
+            register_synthezier(synthesize_vocovov_expression1)
+            register_synthezier(synthesize_covovov_expression1)
+            register_synthezier(synthesize_covocov_expression1)
+            register_synthezier(synthesize_vocovoc_expression1)
+            register_synthezier(synthesize_covovoc_expression1)
+            register_synthezier(synthesize_vococov_expression1)
+
+            register_synthezier(synthesize_vovovov_expression2)
+            register_synthezier(synthesize_vovovoc_expression2)
+            register_synthezier(synthesize_vovocov_expression2)
+            register_synthezier(synthesize_vocovov_expression2)
+            register_synthezier(synthesize_covovov_expression2)
+            register_synthezier(synthesize_covocov_expression2)
+            register_synthezier(synthesize_vocovoc_expression2)
+            register_synthezier(synthesize_covovoc_expression2)
+
+            register_synthezier(synthesize_vovovov_expression3)
+            register_synthezier(synthesize_vovovoc_expression3)
+            register_synthezier(synthesize_vovocov_expression3)
+            register_synthezier(synthesize_vocovov_expression3)
+            register_synthezier(synthesize_covovov_expression3)
+            register_synthezier(synthesize_covocov_expression3)
+            register_synthezier(synthesize_vocovoc_expression3)
+            register_synthezier(synthesize_covovoc_expression3)
+            register_synthezier(synthesize_vococov_expression3)
+
+            register_synthezier(synthesize_vovovov_expression4)
+            register_synthezier(synthesize_vovovoc_expression4)
+            register_synthezier(synthesize_vovocov_expression4)
+            register_synthezier(synthesize_vocovov_expression4)
+            register_synthezier(synthesize_covovov_expression4)
+            register_synthezier(synthesize_covocov_expression4)
+            register_synthezier(synthesize_vocovoc_expression4)
+            register_synthezier(synthesize_covovoc_expression4)
+            #endif
+         }
+
+         inline void set_parser(parser_t& p)
+         {
+            parser_ = &p;
+         }
+
+         inline void set_uom(unary_op_map_t& unary_op_map)
+         {
+            unary_op_map_ = &unary_op_map;
+         }
+
+         inline void set_bom(binary_op_map_t& binary_op_map)
+         {
+            binary_op_map_ = &binary_op_map;
+         }
+
+         inline void set_ibom(inv_binary_op_map_t& inv_binary_op_map)
+         {
+            inv_binary_op_map_ = &inv_binary_op_map;
+         }
+
+         inline void set_sf3m(sf3_map_t& sf3_map)
+         {
+            sf3_map_ = &sf3_map;
+         }
+
+         inline void set_sf4m(sf4_map_t& sf4_map)
+         {
+            sf4_map_ = &sf4_map;
+         }
+
+         inline void set_allocator(details::node_allocator& na)
+         {
+            node_allocator_ = &na;
+         }
+
+         inline void set_strength_reduction_state(const bool enabled)
+         {
+            strength_reduction_enabled_ = enabled;
+         }
+
+         inline bool strength_reduction_enabled() const
+         {
+            return strength_reduction_enabled_;
+         }
+
+         inline bool valid_operator(const details::operator_type& operation, binary_functor_t& bop)
+         {
+            typename binary_op_map_t::iterator bop_itr = binary_op_map_->find(operation);
+
+            if ((*binary_op_map_).end() == bop_itr)
+               return false;
+
+            bop = bop_itr->second;
+
+            return true;
+         }
+
+         inline bool valid_operator(const details::operator_type& operation, unary_functor_t& uop)
+         {
+            typename unary_op_map_t::iterator uop_itr = unary_op_map_->find(operation);
+
+            if ((*unary_op_map_).end() == uop_itr)
+               return false;
+
+            uop = uop_itr->second;
+
+            return true;
+         }
+
+         inline details::operator_type get_operator(const binary_functor_t& bop) const
+         {
+            return (*inv_binary_op_map_).find(bop)->second;
+         }
+
+         inline expression_node_ptr operator() (const Type& v) const
+         {
+            return node_allocator_->allocate<literal_node_t>(v);
+         }
+
+         #ifndef exprtk_disable_string_capabilities
+         inline expression_node_ptr operator() (const std::string& s) const
+         {
+            return node_allocator_->allocate<string_literal_node_t>(s);
+         }
+
+         inline expression_node_ptr operator() (std::string& s, range_t& rp) const
+         {
+            return node_allocator_->allocate_rr<string_range_node_t>(s,rp);
+         }
+
+         inline expression_node_ptr operator() (const std::string& s, range_t& rp) const
+         {
+            return node_allocator_->allocate_tt<const_string_range_node_t>(s,rp);
+         }
+
+         inline expression_node_ptr operator() (expression_node_ptr branch, range_t& rp) const
+         {
+            if (is_generally_string_node(branch))
+               return node_allocator_->allocate_tt<generic_string_range_node_t>(branch,rp);
+            else
+               return error_node();
+         }
+         #endif
+
+         inline bool unary_optimisable(const details::operator_type& operation) const
+         {
+            return (details::e_abs   == operation) || (details::e_acos  == operation) ||
+                   (details::e_acosh == operation) || (details::e_asin  == operation) ||
+                   (details::e_asinh == operation) || (details::e_atan  == operation) ||
+                   (details::e_atanh == operation) || (details::e_ceil  == operation) ||
+                   (details::e_cos   == operation) || (details::e_cosh  == operation) ||
+                   (details::e_exp   == operation) || (details::e_expm1 == operation) ||
+                   (details::e_floor == operation) || (details::e_log   == operation) ||
+                   (details::e_log10 == operation) || (details::e_log2  == operation) ||
+                   (details::e_log1p == operation) || (details::e_neg   == operation) ||
+                   (details::e_pos   == operation) || (details::e_round == operation) ||
+                   (details::e_sin   == operation) || (details::e_sinc  == operation) ||
+                   (details::e_sinh  == operation) || (details::e_sqrt  == operation) ||
+                   (details::e_tan   == operation) || (details::e_tanh  == operation) ||
+                   (details::e_cot   == operation) || (details::e_sec   == operation) ||
+                   (details::e_csc   == operation) || (details::e_r2d   == operation) ||
+                   (details::e_d2r   == operation) || (details::e_d2g   == operation) ||
+                   (details::e_g2d   == operation) || (details::e_notl  == operation) ||
+                   (details::e_sgn   == operation) || (details::e_erf   == operation) ||
+                   (details::e_erfc  == operation) || (details::e_ncdf  == operation) ||
+                   (details::e_frac  == operation) || (details::e_trunc == operation) ;
+         }
+
+         inline bool sf3_optimisable(const std::string& sf3id, trinary_functor_t& tfunc) const
+         {
+            typename sf3_map_t::const_iterator itr = sf3_map_->find(sf3id);
+
+            if (sf3_map_->end() == itr)
+               return false;
+            else
+               tfunc = itr->second.first;
+
+            return true;
+         }
+
+         inline bool sf4_optimisable(const std::string& sf4id, quaternary_functor_t& qfunc) const
+         {
+            typename sf4_map_t::const_iterator itr = sf4_map_->find(sf4id);
+
+            if (sf4_map_->end() == itr)
+               return false;
+            else
+               qfunc = itr->second.first;
+
+            return true;
+         }
+
+         inline bool sf3_optimisable(const std::string& sf3id, details::operator_type& operation) const
+         {
+            typename sf3_map_t::const_iterator itr = sf3_map_->find(sf3id);
+
+            if (sf3_map_->end() == itr)
+               return false;
+            else
+               operation = itr->second.second;
+
+            return true;
+         }
+
+         inline bool sf4_optimisable(const std::string& sf4id, details::operator_type& operation) const
+         {
+            typename sf4_map_t::const_iterator itr = sf4_map_->find(sf4id);
+
+            if (sf4_map_->end() == itr)
+               return false;
+            else
+               operation = itr->second.second;
+
+            return true;
+         }
+
+         inline expression_node_ptr operator() (const details::operator_type& operation, expression_node_ptr (&branch)[1])
+         {
+            if (0 == branch[0])
+            {
+               return error_node();
+            }
+            else if (details::is_null_node(branch[0]))
+            {
+               return branch[0];
+            }
+            else if (details::is_break_node(branch[0]))
+            {
+               return error_node();
+            }
+            else if (details::is_continue_node(branch[0]))
+            {
+               return error_node();
+            }
+            else if (details::is_constant_node(branch[0]))
+            {
+               return synthesize_expression<unary_node_t,1>(operation,branch);
+            }
+            else if (unary_optimisable(operation) && details::is_variable_node(branch[0]))
+            {
+               return synthesize_uv_expression(operation,branch);
+            }
+            else if (unary_optimisable(operation) && details::is_ivector_node(branch[0]))
+            {
+               return synthesize_uvec_expression(operation,branch);
+            }
+            else
+               return synthesize_unary_expression(operation,branch);
+         }
+
+         inline bool is_assignment_operation(const details::operator_type& operation) const
+         {
+            return (
+                     (details::e_addass == operation) ||
+                     (details::e_subass == operation) ||
+                     (details::e_mulass == operation) ||
+                     (details::e_divass == operation) ||
+                     (details::e_modass == operation)
+                   ) &&
+                   parser_->settings_.assignment_enabled(operation);
+         }
+
+         #ifndef exprtk_disable_string_capabilities
+         inline bool valid_string_operation(const details::operator_type& operation) const
+         {
+            return (details::e_add    == operation) ||
+                   (details::e_lt     == operation) ||
+                   (details::e_lte    == operation) ||
+                   (details::e_gt     == operation) ||
+                   (details::e_gte    == operation) ||
+                   (details::e_eq     == operation) ||
+                   (details::e_ne     == operation) ||
+                   (details::e_in     == operation) ||
+                   (details::e_like   == operation) ||
+                   (details::e_ilike  == operation) ||
+                   (details::e_assign == operation) ||
+                   (details::e_addass == operation) ||
+                   (details::e_swap   == operation) ;
+         }
+         #else
+         inline bool valid_string_operation(const details::operator_type&) const
+         {
+            return false;
+         }
+         #endif
+
+         inline std::string to_str(const details::operator_type& operation) const
+         {
+            switch (operation)
+            {
+               case details::e_add  : return "+"      ;
+               case details::e_sub  : return "-"      ;
+               case details::e_mul  : return "*"      ;
+               case details::e_div  : return "/"      ;
+               case details::e_mod  : return "%"      ;
+               case details::e_pow  : return "^"      ;
+               case details::e_lt   : return "<"      ;
+               case details::e_lte  : return "<="     ;
+               case details::e_gt   : return ">"      ;
+               case details::e_gte  : return ">="     ;
+               case details::e_eq   : return "=="     ;
+               case details::e_ne   : return "!="     ;
+               case details::e_and  : return "and"    ;
+               case details::e_nand : return "nand"   ;
+               case details::e_or   : return "or"     ;
+               case details::e_nor  : return "nor"    ;
+               case details::e_xor  : return "xor"    ;
+               case details::e_xnor : return "xnor"   ;
+               default              : return "UNKNOWN";
+            }
+         }
+
+         inline bool operation_optimisable(const details::operator_type& operation) const
+         {
+            return (details::e_add  == operation) ||
+                   (details::e_sub  == operation) ||
+                   (details::e_mul  == operation) ||
+                   (details::e_div  == operation) ||
+                   (details::e_mod  == operation) ||
+                   (details::e_pow  == operation) ||
+                   (details::e_lt   == operation) ||
+                   (details::e_lte  == operation) ||
+                   (details::e_gt   == operation) ||
+                   (details::e_gte  == operation) ||
+                   (details::e_eq   == operation) ||
+                   (details::e_ne   == operation) ||
+                   (details::e_and  == operation) ||
+                   (details::e_nand == operation) ||
+                   (details::e_or   == operation) ||
+                   (details::e_nor  == operation) ||
+                   (details::e_xor  == operation) ||
+                   (details::e_xnor == operation) ;
+         }
+
+         inline std::string branch_to_id(expression_node_ptr branch) const
+         {
+            static const std::string null_str   ("(null)" );
+            static const std::string const_str  ("(c)"    );
+            static const std::string var_str    ("(v)"    );
+            static const std::string vov_str    ("(vov)"  );
+            static const std::string cov_str    ("(cov)"  );
+            static const std::string voc_str    ("(voc)"  );
+            static const std::string str_str    ("(s)"    );
+            static const std::string strrng_str ("(rngs)" );
+            static const std::string cs_str     ("(cs)"   );
+            static const std::string cstrrng_str("(crngs)");
+
+            if (details::is_null_node(branch))
+               return null_str;
+            else if (details::is_constant_node(branch))
+               return const_str;
+            else if (details::is_variable_node(branch))
+               return var_str;
+            else if (details::is_vov_node(branch))
+               return vov_str;
+            else if (details::is_cov_node(branch))
+               return cov_str;
+            else if (details::is_voc_node(branch))
+               return voc_str;
+            else if (details::is_string_node(branch))
+               return str_str;
+            else if (details::is_const_string_node(branch))
+               return cs_str;
+            else if (details::is_string_range_node(branch))
+               return strrng_str;
+            else if (details::is_const_string_range_node(branch))
+               return cstrrng_str;
+            else if (details::is_t0ot1ot2_node(branch))
+               return "(" + dynamic_cast<details::T0oT1oT2_base_node<T>*>(branch)->type_id() + ")";
+            else if (details::is_t0ot1ot2ot3_node(branch))
+               return "(" + dynamic_cast<details::T0oT1oT2oT3_base_node<T>*>(branch)->type_id() + ")";
+            else
+               return "ERROR";
+         }
+
+         inline std::string branch_to_id(expression_node_ptr (&branch)[2]) const
+         {
+            return branch_to_id(branch[0]) + std::string("o") + branch_to_id(branch[1]);
+         }
+
+         inline bool cov_optimisable(const details::operator_type& operation, expression_node_ptr (&branch)[2]) const
+         {
+            if (!operation_optimisable(operation))
+               return false;
+            else
+               return details::is_constant_node(branch[0]) &&
+                      details::is_variable_node(branch[1]) ;
+         }
+
+         inline bool voc_optimisable(const details::operator_type& operation, expression_node_ptr (&branch)[2]) const
+         {
+            if (!operation_optimisable(operation))
+               return false;
+            else
+               return details::is_variable_node(branch[0]) &&
+                      details::is_constant_node(branch[1]) ;
+         }
+
+         inline bool vov_optimisable(const details::operator_type& operation, expression_node_ptr (&branch)[2]) const
+         {
+            if (!operation_optimisable(operation))
+               return false;
+            else
+               return details::is_variable_node(branch[0]) &&
+                      details::is_variable_node(branch[1]) ;
+         }
+
+         inline bool cob_optimisable(const details::operator_type& operation, expression_node_ptr (&branch)[2]) const
+         {
+            if (!operation_optimisable(operation))
+               return false;
+            else
+               return details::is_constant_node(branch[0]) &&
+                     !details::is_constant_node(branch[1]) ;
+         }
+
+         inline bool boc_optimisable(const details::operator_type& operation, expression_node_ptr (&branch)[2]) const
+         {
+            if (!operation_optimisable(operation))
+               return false;
+            else
+               return !details::is_constant_node(branch[0]) &&
+                       details::is_constant_node(branch[1]) ;
+         }
+
+         inline bool cocob_optimisable(const details::operator_type& operation, expression_node_ptr (&branch)[2]) const
+         {
+            if (
+                 (details::e_add == operation) ||
+                 (details::e_sub == operation) ||
+                 (details::e_mul == operation) ||
+                 (details::e_div == operation)
+               )
+            {
+               return (details::is_constant_node(branch[0]) && details::is_cob_node(branch[1])) ||
+                      (details::is_constant_node(branch[1]) && details::is_cob_node(branch[0])) ;
+            }
+            else
+               return false;
+         }
+
+         inline bool coboc_optimisable(const details::operator_type& operation, expression_node_ptr (&branch)[2]) const
+         {
+            if (
+                 (details::e_add == operation) ||
+                 (details::e_sub == operation) ||
+                 (details::e_mul == operation) ||
+                 (details::e_div == operation)
+               )
+            {
+               return (details::is_constant_node(branch[0]) && details::is_boc_node(branch[1])) ||
+                      (details::is_constant_node(branch[1]) && details::is_boc_node(branch[0])) ;
+            }
+            else
+               return false;
+         }
+
+         inline bool uvouv_optimisable(const details::operator_type& operation, expression_node_ptr (&branch)[2]) const
+         {
+            if (!operation_optimisable(operation))
+               return false;
+            else
+               return details::is_uv_node(branch[0]) &&
+                      details::is_uv_node(branch[1]) ;
+         }
+
+         inline bool vob_optimisable(const details::operator_type& operation, expression_node_ptr (&branch)[2]) const
+         {
+            if (!operation_optimisable(operation))
+               return false;
+            else
+               return details::is_variable_node(branch[0]) &&
+                     !details::is_variable_node(branch[1]) ;
+         }
+
+         inline bool bov_optimisable(const details::operator_type& operation, expression_node_ptr (&branch)[2]) const
+         {
+            if (!operation_optimisable(operation))
+               return false;
+            else
+               return !details::is_variable_node(branch[0]) &&
+                       details::is_variable_node(branch[1]) ;
+         }
+
+         inline bool binext_optimisable(const details::operator_type& operation, expression_node_ptr (&branch)[2]) const
+         {
+            if (!operation_optimisable(operation))
+               return false;
+            else
+               return !details::is_constant_node(branch[0]) ||
+                      !details::is_constant_node(branch[1]) ;
+         }
+
+         inline bool is_invalid_assignment_op(const details::operator_type& operation, expression_node_ptr (&branch)[2]) const
+         {
+            if (is_assignment_operation(operation))
+            {
+               const bool b1_is_genstring = details::is_generally_string_node(branch[1]);
+
+               if (details::is_string_node(branch[0]))
+                  return !b1_is_genstring;
+               else
+                  return (
+                           !details::is_variable_node          (branch[0]) &&
+                           !details::is_vector_elem_node       (branch[0]) &&
+                           !details::is_rebasevector_elem_node (branch[0]) &&
+                           !details::is_rebasevector_celem_node(branch[0]) &&
+                           !details::is_vector_node            (branch[0])
+                         )
+                         || b1_is_genstring;
+            }
+            else
+               return false;
+         }
+
+         inline bool is_constpow_operation(const details::operator_type& operation, expression_node_ptr(&branch)[2]) const
+         {
+            if (
+                 !details::is_constant_node(branch[1]) ||
+                  details::is_constant_node(branch[0]) ||
+                  details::is_variable_node(branch[0]) ||
+                  details::is_vector_node  (branch[0]) ||
+                  details::is_generally_string_node(branch[0])
+               )
+               return false;
+
+            const Type c = static_cast<details::literal_node<Type>*>(branch[1])->value();
+
+            return cardinal_pow_optimisable(operation, c);
+         }
+
+         inline bool is_invalid_break_continue_op(expression_node_ptr (&branch)[2]) const
+         {
+            return (
+                     details::is_break_node   (branch[0]) ||
+                     details::is_break_node   (branch[1]) ||
+                     details::is_continue_node(branch[0]) ||
+                     details::is_continue_node(branch[1])
+                   );
+         }
+
+         inline bool is_invalid_string_op(const details::operator_type& operation, expression_node_ptr (&branch)[2]) const
+         {
+            const bool b0_string = is_generally_string_node(branch[0]);
+            const bool b1_string = is_generally_string_node(branch[1]);
+
+            bool result = false;
+
+            if (b0_string != b1_string)
+               result = true;
+            else if (!valid_string_operation(operation) && b0_string && b1_string)
+               result = true;
+
+            if (result)
+            {
+               parser_->set_synthesis_error("Invalid string operation");
+            }
+
+            return result;
+         }
+
+         inline bool is_invalid_string_op(const details::operator_type& operation, expression_node_ptr (&branch)[3]) const
+         {
+            const bool b0_string = is_generally_string_node(branch[0]);
+            const bool b1_string = is_generally_string_node(branch[1]);
+            const bool b2_string = is_generally_string_node(branch[2]);
+
+            bool result = false;
+
+            if ((b0_string != b1_string) || (b1_string != b2_string))
+               result = true;
+            else if ((details::e_inrange != operation) && b0_string && b1_string && b2_string)
+               result = true;
+
+            if (result)
+            {
+               parser_->set_synthesis_error("Invalid string operation");
+            }
+
+            return result;
+         }
+
+         inline bool is_string_operation(const details::operator_type& operation, expression_node_ptr (&branch)[2]) const
+         {
+            const bool b0_string = is_generally_string_node(branch[0]);
+            const bool b1_string = is_generally_string_node(branch[1]);
+
+            return (b0_string && b1_string && valid_string_operation(operation));
+         }
+
+         inline bool is_string_operation(const details::operator_type& operation, expression_node_ptr (&branch)[3]) const
+         {
+            const bool b0_string = is_generally_string_node(branch[0]);
+            const bool b1_string = is_generally_string_node(branch[1]);
+            const bool b2_string = is_generally_string_node(branch[2]);
+
+            return (b0_string && b1_string && b2_string && (details::e_inrange == operation));
+         }
+
+         #ifndef exprtk_disable_sc_andor
+         inline bool is_shortcircuit_expression(const details::operator_type& operation) const
+         {
+            return (
+                     (details::e_scand == operation) ||
+                     (details::e_scor  == operation)
+                   );
+         }
+         #else
+         inline bool is_shortcircuit_expression(const details::operator_type&) const
+         {
+            return false;
+         }
+         #endif
+
+         inline bool is_null_present(expression_node_ptr (&branch)[2]) const
+         {
+            return (
+                     details::is_null_node(branch[0]) ||
+                     details::is_null_node(branch[1])
+                   );
+         }
+
+         inline bool is_vector_eqineq_logic_operation(const details::operator_type& operation, expression_node_ptr (&branch)[2]) const
+         {
+            if (!is_ivector_node(branch[0]) && !is_ivector_node(branch[1]))
+               return false;
+            else
+               return (
+                        (details::e_lt    == operation) ||
+                        (details::e_lte   == operation) ||
+                        (details::e_gt    == operation) ||
+                        (details::e_gte   == operation) ||
+                        (details::e_eq    == operation) ||
+                        (details::e_ne    == operation) ||
+                        (details::e_equal == operation) ||
+                        (details::e_and   == operation) ||
+                        (details::e_nand  == operation) ||
+                        (details::  e_or  == operation) ||
+                        (details:: e_nor  == operation) ||
+                        (details:: e_xor  == operation) ||
+                        (details::e_xnor  == operation)
+                      );
+         }
+
+         inline bool is_vector_arithmetic_operation(const details::operator_type& operation, expression_node_ptr (&branch)[2]) const
+         {
+            if (!is_ivector_node(branch[0]) && !is_ivector_node(branch[1]))
+               return false;
+            else
+               return (
+                        (details::e_add == operation) ||
+                        (details::e_sub == operation) ||
+                        (details::e_mul == operation) ||
+                        (details::e_div == operation) ||
+                        (details::e_pow == operation)
+                      );
+         }
+
+         inline expression_node_ptr operator() (const details::operator_type& operation, expression_node_ptr (&branch)[2])
+         {
+            if ((0 == branch[0]) || (0 == branch[1]))
+            {
+               return error_node();
+            }
+            else if (is_invalid_string_op(operation,branch))
+            {
+               return error_node();
+            }
+            else if (is_invalid_assignment_op(operation,branch))
+            {
+               return error_node();
+            }
+            else if (is_invalid_break_continue_op(branch))
+            {
+               return error_node();
+            }
+            else if (details::e_assign == operation)
+            {
+               return synthesize_assignment_expression(operation, branch);
+            }
+            else if (details::e_swap == operation)
+            {
+               return synthesize_swap_expression(branch);
+            }
+            else if (is_assignment_operation(operation))
+            {
+               return synthesize_assignment_operation_expression(operation, branch);
+            }
+            else if (is_vector_eqineq_logic_operation(operation, branch))
+            {
+               return synthesize_veceqineqlogic_operation_expression(operation, branch);
+            }
+            else if (is_vector_arithmetic_operation(operation, branch))
+            {
+               return synthesize_vecarithmetic_operation_expression(operation, branch);
+            }
+            else if (is_shortcircuit_expression(operation))
+            {
+               return synthesize_shortcircuit_expression(operation, branch);
+            }
+            else if (is_string_operation(operation, branch))
+            {
+               return synthesize_string_expression(operation, branch);
+            }
+            else if (is_null_present(branch))
+            {
+               return synthesize_null_expression(operation, branch);
+            }
+            #ifndef exprtk_disable_cardinal_pow_optimisation
+            else if (is_constpow_operation(operation, branch))
+            {
+               return cardinal_pow_optimisation(branch);
+            }
+            #endif
+
+            expression_node_ptr result = error_node();
+
+            #ifndef exprtk_disable_enhanced_features
+            if (synthesize_expression(operation, branch, result))
+            {
+               return result;
+            }
+            else
+            #endif
+
+            {
+               /*
+                  Possible reductions:
+                  1. c o cob -> cob
+                  2. cob o c -> cob
+                  3. c o boc -> boc
+                  4. boc o c -> boc
+               */
+               result = error_node();
+
+               if (cocob_optimisable(operation, branch))
+               {
+                  result = synthesize_cocob_expression::process((*this), operation, branch);
+               }
+               else if (coboc_optimisable(operation, branch) && (0 == result))
+               {
+                  result = synthesize_coboc_expression::process((*this), operation, branch);
+               }
+
+               if (result)
+                  return result;
+            }
+
+            if (uvouv_optimisable(operation, branch))
+            {
+               return synthesize_uvouv_expression(operation, branch);
+            }
+            else if (vob_optimisable(operation, branch))
+            {
+               return synthesize_vob_expression::process((*this), operation, branch);
+            }
+            else if (bov_optimisable(operation, branch))
+            {
+               return synthesize_bov_expression::process((*this), operation, branch);
+            }
+            else if (cob_optimisable(operation, branch))
+            {
+               return synthesize_cob_expression::process((*this), operation, branch);
+            }
+            else if (boc_optimisable(operation, branch))
+            {
+               return synthesize_boc_expression::process((*this), operation, branch);
+            }
+            #ifndef exprtk_disable_enhanced_features
+            else if (cov_optimisable(operation, branch))
+            {
+               return synthesize_cov_expression::process((*this), operation, branch);
+            }
+            #endif
+            else if (binext_optimisable(operation, branch))
+            {
+               return synthesize_binary_ext_expression::process((*this), operation, branch);
+            }
+            else
+               return synthesize_expression<binary_node_t,2>(operation, branch);
+         }
+
+         inline expression_node_ptr operator() (const details::operator_type& operation, expression_node_ptr (&branch)[3])
+         {
+            if (
+                 (0 == branch[0]) ||
+                 (0 == branch[1]) ||
+                 (0 == branch[2])
+               )
+            {
+               details::free_all_nodes(*node_allocator_,branch);
+
+               return error_node();
+            }
+            else if (is_invalid_string_op(operation, branch))
+            {
+               return error_node();
+            }
+            else if (is_string_operation(operation, branch))
+            {
+               return synthesize_string_expression(operation, branch);
+            }
+            else
+               return synthesize_expression<trinary_node_t,3>(operation, branch);
+         }
+
+         inline expression_node_ptr operator() (const details::operator_type& operation, expression_node_ptr (&branch)[4])
+         {
+            return synthesize_expression<quaternary_node_t,4>(operation,branch);
+         }
+
+         inline expression_node_ptr operator() (const details::operator_type& operation, expression_node_ptr b0)
+         {
+            expression_node_ptr branch[1] = { b0 };
+            return (*this)(operation,branch);
+         }
+
+         inline expression_node_ptr operator() (const details::operator_type& operation, expression_node_ptr& b0, expression_node_ptr& b1)
+         {
+            expression_node_ptr result = error_node();
+
+            if ((0 != b0) && (0 != b1))
+            {
+               expression_node_ptr branch[2] = { b0, b1 };
+               result = expression_generator<Type>::operator()(operation, branch);
+               b0 = branch[0];
+               b1 = branch[1];
+            }
+
+            return result;
+         }
+
+         inline expression_node_ptr conditional(expression_node_ptr condition,
+                                                expression_node_ptr consequent,
+                                                expression_node_ptr alternative) const
+         {
+            if ((0 == condition) || (0 == consequent))
+            {
+               free_node(*node_allocator_,   condition);
+               free_node(*node_allocator_,  consequent);
+               free_node(*node_allocator_, alternative);
+
+               return error_node();
+            }
+            // Can the condition be immediately evaluated? if so optimise.
+            else if (details::is_constant_node(condition))
+            {
+               // True branch
+               if (details::is_true(condition))
+               {
+                  free_node(*node_allocator_,   condition);
+                  free_node(*node_allocator_, alternative);
+
+                  return consequent;
+               }
+               // False branch
+               else
+               {
+                  free_node(*node_allocator_,  condition);
+                  free_node(*node_allocator_, consequent);
+
+                  if (alternative)
+                     return alternative;
+                  else
+                     return node_allocator_->allocate<details::null_node<T> >();
+               }
+            }
+            else if ((0 != consequent) && (0 != alternative))
+            {
+               return node_allocator_->
+                        allocate<conditional_node_t>(condition, consequent, alternative);
+            }
+            else
+               return node_allocator_->
+                        allocate<cons_conditional_node_t>(condition, consequent);
+         }
+
+         #ifndef exprtk_disable_string_capabilities
+         inline expression_node_ptr conditional_string(expression_node_ptr condition,
+                                                       expression_node_ptr consequent,
+                                                       expression_node_ptr alternative) const
+         {
+            if ((0 == condition) || (0 == consequent))
+            {
+               free_node(*node_allocator_,   condition);
+               free_node(*node_allocator_,  consequent);
+               free_node(*node_allocator_, alternative);
+
+               return error_node();
+            }
+            // Can the condition be immediately evaluated? if so optimise.
+            else if (details::is_constant_node(condition))
+            {
+               // True branch
+               if (details::is_true(condition))
+               {
+                  free_node(*node_allocator_,   condition);
+                  free_node(*node_allocator_, alternative);
+
+                  return consequent;
+               }
+               // False branch
+               else
+               {
+                  free_node(*node_allocator_,  condition);
+                  free_node(*node_allocator_, consequent);
+
+                  if (alternative)
+                     return alternative;
+                  else
+                     return node_allocator_->
+                              allocate_c<details::string_literal_node<Type> >("");
+               }
+            }
+            else if ((0 != consequent) && (0 != alternative))
+               return node_allocator_->
+                        allocate<conditional_string_node_t>(condition, consequent, alternative);
+            else
+               return error_node();
+         }
+         #else
+         inline expression_node_ptr conditional_string(expression_node_ptr,
+                                                       expression_node_ptr,
+                                                       expression_node_ptr) const
+         {
+            return error_node();
+         }
+         #endif
+
+         inline expression_node_ptr while_loop(expression_node_ptr& condition,
+                                               expression_node_ptr& branch,
+                                               const bool brkcont = false) const
+         {
+            if (!brkcont && details::is_constant_node(condition))
+            {
+               expression_node_ptr result = error_node();
+               if (details::is_true(condition))
+                  // Infinite loops are not allowed.
+                  result = error_node();
+               else
+                  result = node_allocator_->allocate<details::null_node<Type> >();
+
+               free_node(*node_allocator_, condition);
+               free_node(*node_allocator_,    branch);
+
+               return result;
+            }
+            else if (details::is_null_node(condition))
+            {
+               free_node(*node_allocator_,condition);
+
+               return branch;
+            }
+            else if (!brkcont)
+               return node_allocator_->allocate<while_loop_node_t>(condition,branch);
+            #ifndef exprtk_disable_break_continue
+            else
+               return node_allocator_->allocate<while_loop_bc_node_t>(condition,branch);
+            #else
+               return error_node();
+            #endif
+         }
+
+         inline expression_node_ptr repeat_until_loop(expression_node_ptr& condition,
+                                                      expression_node_ptr& branch,
+                                                      const bool brkcont = false) const
+         {
+            if (!brkcont && details::is_constant_node(condition))
+            {
+               if (
+                    details::is_true(condition) &&
+                    details::is_constant_node(branch)
+                  )
+               {
+                  free_node(*node_allocator_,condition);
+
+                  return branch;
+               }
+
+               free_node(*node_allocator_, condition);
+               free_node(*node_allocator_,    branch);
+
+               return error_node();
+            }
+            else if (details::is_null_node(condition))
+            {
+               free_node(*node_allocator_,condition);
+
+               return branch;
+            }
+            else if (!brkcont)
+               return node_allocator_->allocate<repeat_until_loop_node_t>(condition,branch);
+            #ifndef exprtk_disable_break_continue
+            else
+               return node_allocator_->allocate<repeat_until_loop_bc_node_t>(condition,branch);
+            #else
+               return error_node();
+            #endif
+         }
+
+         inline expression_node_ptr for_loop(expression_node_ptr& initialiser,
+                                             expression_node_ptr& condition,
+                                             expression_node_ptr& incrementor,
+                                             expression_node_ptr& loop_body,
+                                             bool brkcont = false) const
+         {
+            if (!brkcont && details::is_constant_node(condition))
+            {
+               expression_node_ptr result = error_node();
+
+               if (details::is_true(condition))
+                  // Infinite loops are not allowed.
+                  result = error_node();
+               else
+                  result = node_allocator_->allocate<details::null_node<Type> >();
+
+               free_node(*node_allocator_, initialiser);
+               free_node(*node_allocator_,   condition);
+               free_node(*node_allocator_, incrementor);
+               free_node(*node_allocator_,   loop_body);
+
+               return result;
+            }
+            else if (details::is_null_node(condition) || (0 == condition))
+            {
+               free_node(*node_allocator_, initialiser);
+               free_node(*node_allocator_,   condition);
+               free_node(*node_allocator_, incrementor);
+
+               return loop_body;
+            }
+            else if (!brkcont)
+               return node_allocator_->allocate<for_loop_node_t>
+                                       (
+                                         initialiser,
+                                         condition,
+                                         incrementor,
+                                         loop_body
+                                       );
+
+            #ifndef exprtk_disable_break_continue
+            else
+               return node_allocator_->allocate<for_loop_bc_node_t>
+                                       (
+                                         initialiser,
+                                         condition,
+                                         incrementor,
+                                         loop_body
+                                       );
+            #else
+            return error_node();
+            #endif
+         }
+
+         template <typename Allocator,
+                   template <typename, typename> class Sequence>
+         inline expression_node_ptr const_optimise_switch(Sequence<expression_node_ptr,Allocator>& arg_list)
+         {
+            expression_node_ptr result = error_node();
+
+            for (std::size_t i = 0; i < (arg_list.size() / 2); ++i)
+            {
+               expression_node_ptr condition  = arg_list[(2 * i)    ];
+               expression_node_ptr consequent = arg_list[(2 * i) + 1];
+
+               if ((0 == result) && details::is_true(condition))
+               {
+                  result = consequent;
+                  break;
+               }
+            }
+
+            if (0 == result)
+            {
+               result = arg_list.back();
+            }
+
+            for (std::size_t i = 0; i < arg_list.size(); ++i)
+            {
+               expression_node_ptr current_expr = arg_list[i];
+
+               if (current_expr && (current_expr != result))
+               {
+                  free_node(*node_allocator_,current_expr);
+               }
+            }
+
+            return result;
+         }
+
+         template <typename Allocator,
+                   template <typename, typename> class Sequence>
+         inline expression_node_ptr const_optimise_mswitch(Sequence<expression_node_ptr,Allocator>& arg_list)
+         {
+            expression_node_ptr result = error_node();
+
+            for (std::size_t i = 0; i < (arg_list.size() / 2); ++i)
+            {
+               expression_node_ptr condition  = arg_list[(2 * i)    ];
+               expression_node_ptr consequent = arg_list[(2 * i) + 1];
+
+               if (details::is_true(condition))
+               {
+                  result = consequent;
+               }
+            }
+
+            if (0 == result)
+            {
+               T zero = T(0);
+               result = node_allocator_->allocate<literal_node_t>(zero);
+            }
+
+            for (std::size_t i = 0; i < arg_list.size(); ++i)
+            {
+               expression_node_ptr& current_expr = arg_list[i];
+
+               if (current_expr && (current_expr != result))
+               {
+                  free_node(*node_allocator_,current_expr);
+               }
+            }
+
+            return result;
+         }
+
+         struct switch_nodes
+         {
+            typedef std::vector<expression_node_ptr> arg_list_t;
+
+            #define case_stmt(N)                                             \
+            if (is_true(arg[(2 * N)])) { return arg[(2 * N) + 1]->value(); } \
+
+            struct switch_1
+            {
+               static inline T process(const arg_list_t& arg)
+               {
+                  case_stmt(0)
+
+                  return arg.back()->value();
+               }
+            };
+
+            struct switch_2
+            {
+               static inline T process(const arg_list_t& arg)
+               {
+                  case_stmt(0) case_stmt(1)
+
+                  return arg.back()->value();
+               }
+            };
+
+            struct switch_3
+            {
+               static inline T process(const arg_list_t& arg)
+               {
+                  case_stmt(0) case_stmt(1)
+                  case_stmt(2)
+
+                  return arg.back()->value();
+               }
+            };
+
+            struct switch_4
+            {
+               static inline T process(const arg_list_t& arg)
+               {
+                  case_stmt(0) case_stmt(1)
+                  case_stmt(2) case_stmt(3)
+
+                  return arg.back()->value();
+               }
+            };
+
+            struct switch_5
+            {
+               static inline T process(const arg_list_t& arg)
+               {
+                  case_stmt(0) case_stmt(1)
+                  case_stmt(2) case_stmt(3)
+                  case_stmt(4)
+
+                  return arg.back()->value();
+               }
+            };
+
+            struct switch_6
+            {
+               static inline T process(const arg_list_t& arg)
+               {
+                  case_stmt(0) case_stmt(1)
+                  case_stmt(2) case_stmt(3)
+                  case_stmt(4) case_stmt(5)
+
+                  return arg.back()->value();
+               }
+            };
+
+            struct switch_7
+            {
+               static inline T process(const arg_list_t& arg)
+               {
+                  case_stmt(0) case_stmt(1)
+                  case_stmt(2) case_stmt(3)
+                  case_stmt(4) case_stmt(5)
+                  case_stmt(6)
+
+                  return arg.back()->value();
+               }
+            };
+
+            #undef case_stmt
+         };
+
+         template <typename Allocator,
+                   template <typename, typename> class Sequence>
+         inline expression_node_ptr switch_statement(Sequence<expression_node_ptr,Allocator>& arg_list)
+         {
+            if (arg_list.empty())
+               return error_node();
+            else if (
+                      !all_nodes_valid(arg_list)   ||
+                      (arg_list.size() < 3)        ||
+                      ((arg_list.size() % 2) != 1)
+                    )
+            {
+               details::free_all_nodes(*node_allocator_,arg_list);
+
+               return error_node();
+            }
+            else if (is_constant_foldable(arg_list))
+               return const_optimise_switch(arg_list);
+
+            switch ((arg_list.size() - 1) / 2)
+            {
+               #define case_stmt(N)                                                 \
+               case N :                                                             \
+                  return node_allocator_->                                          \
+                            allocate<details::switch_n_node                         \
+                              <Type,typename switch_nodes::switch_##N> >(arg_list); \
+
+               case_stmt(1)
+               case_stmt(2)
+               case_stmt(3)
+               case_stmt(4)
+               case_stmt(5)
+               case_stmt(6)
+               case_stmt(7)
+               #undef case_stmt
+
+               default : return node_allocator_->allocate<details::switch_node<Type> >(arg_list);
+            }
+         }
+
+         template <typename Allocator,
+                   template <typename, typename> class Sequence>
+         inline expression_node_ptr multi_switch_statement(Sequence<expression_node_ptr,Allocator>& arg_list)
+         {
+            if (!all_nodes_valid(arg_list))
+            {
+               details::free_all_nodes(*node_allocator_,arg_list);
+
+               return error_node();
+            }
+            else if (is_constant_foldable(arg_list))
+               return const_optimise_mswitch(arg_list);
+            else
+               return node_allocator_->allocate<details::multi_switch_node<Type> >(arg_list);
+         }
+
+         #define unary_opr_switch_statements            \
+         case_stmt(details::  e_abs, details::  abs_op) \
+         case_stmt(details:: e_acos, details:: acos_op) \
+         case_stmt(details::e_acosh, details::acosh_op) \
+         case_stmt(details:: e_asin, details:: asin_op) \
+         case_stmt(details::e_asinh, details::asinh_op) \
+         case_stmt(details:: e_atan, details:: atan_op) \
+         case_stmt(details::e_atanh, details::atanh_op) \
+         case_stmt(details:: e_ceil, details:: ceil_op) \
+         case_stmt(details::  e_cos, details::  cos_op) \
+         case_stmt(details:: e_cosh, details:: cosh_op) \
+         case_stmt(details::  e_exp, details::  exp_op) \
+         case_stmt(details::e_expm1, details::expm1_op) \
+         case_stmt(details::e_floor, details::floor_op) \
+         case_stmt(details::  e_log, details::  log_op) \
+         case_stmt(details::e_log10, details::log10_op) \
+         case_stmt(details:: e_log2, details:: log2_op) \
+         case_stmt(details::e_log1p, details::log1p_op) \
+         case_stmt(details::  e_neg, details::  neg_op) \
+         case_stmt(details::  e_pos, details::  pos_op) \
+         case_stmt(details::e_round, details::round_op) \
+         case_stmt(details::  e_sin, details::  sin_op) \
+         case_stmt(details:: e_sinc, details:: sinc_op) \
+         case_stmt(details:: e_sinh, details:: sinh_op) \
+         case_stmt(details:: e_sqrt, details:: sqrt_op) \
+         case_stmt(details::  e_tan, details::  tan_op) \
+         case_stmt(details:: e_tanh, details:: tanh_op) \
+         case_stmt(details::  e_cot, details::  cot_op) \
+         case_stmt(details::  e_sec, details::  sec_op) \
+         case_stmt(details::  e_csc, details::  csc_op) \
+         case_stmt(details::  e_r2d, details::  r2d_op) \
+         case_stmt(details::  e_d2r, details::  d2r_op) \
+         case_stmt(details::  e_d2g, details::  d2g_op) \
+         case_stmt(details::  e_g2d, details::  g2d_op) \
+         case_stmt(details:: e_notl, details:: notl_op) \
+         case_stmt(details::  e_sgn, details::  sgn_op) \
+         case_stmt(details::  e_erf, details::  erf_op) \
+         case_stmt(details:: e_erfc, details:: erfc_op) \
+         case_stmt(details:: e_ncdf, details:: ncdf_op) \
+         case_stmt(details:: e_frac, details:: frac_op) \
+         case_stmt(details::e_trunc, details::trunc_op) \
+
+         inline expression_node_ptr synthesize_uv_expression(const details::operator_type& operation,
+                                                             expression_node_ptr (&branch)[1])
+         {
+            T& v = static_cast<details::variable_node<T>*>(branch[0])->ref();
+
+            switch (operation)
+            {
+               #define case_stmt(op0,op1)                                                          \
+               case op0 : return node_allocator_->                                                 \
+                             allocate<typename details::unary_variable_node<Type,op1<Type> > >(v); \
+
+               unary_opr_switch_statements
+               #undef case_stmt
+               default : return error_node();
+            }
+         }
+
+         inline expression_node_ptr synthesize_uvec_expression(const details::operator_type& operation,
+                                                               expression_node_ptr (&branch)[1])
+         {
+            switch (operation)
+            {
+               #define case_stmt(op0,op1)                                                    \
+               case op0 : return node_allocator_->                                           \
+                             allocate<typename details::unary_vector_node<Type,op1<Type> > > \
+                                (operation, branch[0]);                                      \
+
+               unary_opr_switch_statements
+               #undef case_stmt
+               default : return error_node();
+            }
+         }
+
+         inline expression_node_ptr synthesize_unary_expression(const details::operator_type& operation,
+                                                                expression_node_ptr (&branch)[1])
+         {
+            switch (operation)
+            {
+               #define case_stmt(op0,op1)                                                                \
+               case op0 : return node_allocator_->                                                       \
+                             allocate<typename details::unary_branch_node<Type,op1<Type> > >(branch[0]); \
+
+               unary_opr_switch_statements
+               #undef case_stmt
+               default : return error_node();
+            }
+         }
+
+         inline expression_node_ptr const_optimise_sf3(const details::operator_type& operation,
+                                                       expression_node_ptr (&branch)[3])
+         {
+            expression_node_ptr temp_node = error_node();
+
+            switch (operation)
+            {
+               #define case_stmt(op)                                                        \
+               case details::e_sf##op : temp_node = node_allocator_->                       \
+                             allocate<details::sf3_node<Type,details::sf##op##_op<Type> > > \
+                                (operation, branch);                                        \
+                             break;                                                         \
+
+               case_stmt(00) case_stmt(01) case_stmt(02) case_stmt(03)
+               case_stmt(04) case_stmt(05) case_stmt(06) case_stmt(07)
+               case_stmt(08) case_stmt(09) case_stmt(10) case_stmt(11)
+               case_stmt(12) case_stmt(13) case_stmt(14) case_stmt(15)
+               case_stmt(16) case_stmt(17) case_stmt(18) case_stmt(19)
+               case_stmt(20) case_stmt(21) case_stmt(22) case_stmt(23)
+               case_stmt(24) case_stmt(25) case_stmt(26) case_stmt(27)
+               case_stmt(28) case_stmt(29) case_stmt(30) case_stmt(31)
+               case_stmt(32) case_stmt(33) case_stmt(34) case_stmt(35)
+               case_stmt(36) case_stmt(37) case_stmt(38) case_stmt(39)
+               case_stmt(40) case_stmt(41) case_stmt(42) case_stmt(43)
+               case_stmt(44) case_stmt(45) case_stmt(46) case_stmt(47)
+               #undef case_stmt
+               default : return error_node();
+            }
+
+            const T v = temp_node->value();
+
+            details::free_node(*node_allocator_,temp_node);
+
+            return node_allocator_->allocate<literal_node_t>(v);
+         }
+
+         inline expression_node_ptr varnode_optimise_sf3(const details::operator_type& operation, expression_node_ptr (&branch)[3])
+         {
+            typedef details::variable_node<Type>* variable_ptr;
+
+            const Type& v0 = static_cast<variable_ptr>(branch[0])->ref();
+            const Type& v1 = static_cast<variable_ptr>(branch[1])->ref();
+            const Type& v2 = static_cast<variable_ptr>(branch[2])->ref();
+
+            switch (operation)
+            {
+               #define case_stmt(op)                                                                \
+               case details::e_sf##op : return node_allocator_->                                    \
+                             allocate_rrr<details::sf3_var_node<Type,details::sf##op##_op<Type> > > \
+                                (v0, v1, v2);                                                       \
+
+               case_stmt(00) case_stmt(01) case_stmt(02) case_stmt(03)
+               case_stmt(04) case_stmt(05) case_stmt(06) case_stmt(07)
+               case_stmt(08) case_stmt(09) case_stmt(10) case_stmt(11)
+               case_stmt(12) case_stmt(13) case_stmt(14) case_stmt(15)
+               case_stmt(16) case_stmt(17) case_stmt(18) case_stmt(19)
+               case_stmt(20) case_stmt(21) case_stmt(22) case_stmt(23)
+               case_stmt(24) case_stmt(25) case_stmt(26) case_stmt(27)
+               case_stmt(28) case_stmt(29) case_stmt(30) case_stmt(31)
+               case_stmt(32) case_stmt(33) case_stmt(34) case_stmt(35)
+               case_stmt(36) case_stmt(37) case_stmt(38) case_stmt(39)
+               case_stmt(40) case_stmt(41) case_stmt(42) case_stmt(43)
+               case_stmt(44) case_stmt(45) case_stmt(46) case_stmt(47)
+               #undef case_stmt
+               default : return error_node();
+            }
+         }
+
+         inline expression_node_ptr special_function(const details::operator_type& operation, expression_node_ptr (&branch)[3])
+         {
+            if (!all_nodes_valid(branch))
+               return error_node();
+            else if (is_constant_foldable(branch))
+               return const_optimise_sf3(operation,branch);
+            else if (all_nodes_variables(branch))
+               return varnode_optimise_sf3(operation,branch);
+            else
+            {
+               switch (operation)
+               {
+                  #define case_stmt(op)                                                        \
+                  case details::e_sf##op : return node_allocator_->                            \
+                                allocate<details::sf3_node<Type,details::sf##op##_op<Type> > > \
+                                   (operation, branch);                                        \
+
+                  case_stmt(00) case_stmt(01) case_stmt(02) case_stmt(03)
+                  case_stmt(04) case_stmt(05) case_stmt(06) case_stmt(07)
+                  case_stmt(08) case_stmt(09) case_stmt(10) case_stmt(11)
+                  case_stmt(12) case_stmt(13) case_stmt(14) case_stmt(15)
+                  case_stmt(16) case_stmt(17) case_stmt(18) case_stmt(19)
+                  case_stmt(20) case_stmt(21) case_stmt(22) case_stmt(23)
+                  case_stmt(24) case_stmt(25) case_stmt(26) case_stmt(27)
+                  case_stmt(28) case_stmt(29) case_stmt(30) case_stmt(31)
+                  case_stmt(32) case_stmt(33) case_stmt(34) case_stmt(35)
+                  case_stmt(36) case_stmt(37) case_stmt(38) case_stmt(39)
+                  case_stmt(40) case_stmt(41) case_stmt(42) case_stmt(43)
+                  case_stmt(44) case_stmt(45) case_stmt(46) case_stmt(47)
+                  #undef case_stmt
+                  default : return error_node();
+               }
+            }
+         }
+
+         inline expression_node_ptr const_optimise_sf4(const details::operator_type& operation, expression_node_ptr (&branch)[4])
+         {
+            expression_node_ptr temp_node = error_node();
+
+            switch (operation)
+            {
+               #define case_stmt(op)                                                                    \
+               case details::e_sf##op : temp_node = node_allocator_->                                   \
+                                         allocate<details::sf4_node<Type,details::sf##op##_op<Type> > > \
+                                            (operation, branch);                                        \
+                                        break;                                                          \
+
+               case_stmt(48) case_stmt(49) case_stmt(50) case_stmt(51)
+               case_stmt(52) case_stmt(53) case_stmt(54) case_stmt(55)
+               case_stmt(56) case_stmt(57) case_stmt(58) case_stmt(59)
+               case_stmt(60) case_stmt(61) case_stmt(62) case_stmt(63)
+               case_stmt(64) case_stmt(65) case_stmt(66) case_stmt(67)
+               case_stmt(68) case_stmt(69) case_stmt(70) case_stmt(71)
+               case_stmt(72) case_stmt(73) case_stmt(74) case_stmt(75)
+               case_stmt(76) case_stmt(77) case_stmt(78) case_stmt(79)
+               case_stmt(80) case_stmt(81) case_stmt(82) case_stmt(83)
+               case_stmt(84) case_stmt(85) case_stmt(86) case_stmt(87)
+               case_stmt(88) case_stmt(89) case_stmt(90) case_stmt(91)
+               case_stmt(92) case_stmt(93) case_stmt(94) case_stmt(95)
+               case_stmt(96) case_stmt(97) case_stmt(98) case_stmt(99)
+               #undef case_stmt
+               default : return error_node();
+            }
+
+            const T v = temp_node->value();
+
+            details::free_node(*node_allocator_,temp_node);
+
+            return node_allocator_->allocate<literal_node_t>(v);
+         }
+
+         inline expression_node_ptr varnode_optimise_sf4(const details::operator_type& operation, expression_node_ptr (&branch)[4])
+         {
+            typedef details::variable_node<Type>* variable_ptr;
+
+            const Type& v0 = static_cast<variable_ptr>(branch[0])->ref();
+            const Type& v1 = static_cast<variable_ptr>(branch[1])->ref();
+            const Type& v2 = static_cast<variable_ptr>(branch[2])->ref();
+            const Type& v3 = static_cast<variable_ptr>(branch[3])->ref();
+
+            switch (operation)
+            {
+               #define case_stmt(op)                                                                 \
+               case details::e_sf##op : return node_allocator_->                                     \
+                             allocate_rrrr<details::sf4_var_node<Type,details::sf##op##_op<Type> > > \
+                                (v0, v1, v2, v3);                                                    \
+
+               case_stmt(48) case_stmt(49) case_stmt(50) case_stmt(51)
+               case_stmt(52) case_stmt(53) case_stmt(54) case_stmt(55)
+               case_stmt(56) case_stmt(57) case_stmt(58) case_stmt(59)
+               case_stmt(60) case_stmt(61) case_stmt(62) case_stmt(63)
+               case_stmt(64) case_stmt(65) case_stmt(66) case_stmt(67)
+               case_stmt(68) case_stmt(69) case_stmt(70) case_stmt(71)
+               case_stmt(72) case_stmt(73) case_stmt(74) case_stmt(75)
+               case_stmt(76) case_stmt(77) case_stmt(78) case_stmt(79)
+               case_stmt(80) case_stmt(81) case_stmt(82) case_stmt(83)
+               case_stmt(84) case_stmt(85) case_stmt(86) case_stmt(87)
+               case_stmt(88) case_stmt(89) case_stmt(90) case_stmt(91)
+               case_stmt(92) case_stmt(93) case_stmt(94) case_stmt(95)
+               case_stmt(96) case_stmt(97) case_stmt(98) case_stmt(99)
+               #undef case_stmt
+               default : return error_node();
+            }
+         }
+
+         inline expression_node_ptr special_function(const details::operator_type& operation, expression_node_ptr (&branch)[4])
+         {
+            if (!all_nodes_valid(branch))
+               return error_node();
+            else if (is_constant_foldable(branch))
+               return const_optimise_sf4(operation,branch);
+            else if (all_nodes_variables(branch))
+               return varnode_optimise_sf4(operation,branch);
+            switch (operation)
+            {
+               #define case_stmt(op)                                                        \
+               case details::e_sf##op : return node_allocator_->                            \
+                             allocate<details::sf4_node<Type,details::sf##op##_op<Type> > > \
+                                (operation, branch);                                        \
+
+               case_stmt(48) case_stmt(49) case_stmt(50) case_stmt(51)
+               case_stmt(52) case_stmt(53) case_stmt(54) case_stmt(55)
+               case_stmt(56) case_stmt(57) case_stmt(58) case_stmt(59)
+               case_stmt(60) case_stmt(61) case_stmt(62) case_stmt(63)
+               case_stmt(64) case_stmt(65) case_stmt(66) case_stmt(67)
+               case_stmt(68) case_stmt(69) case_stmt(70) case_stmt(71)
+               case_stmt(72) case_stmt(73) case_stmt(74) case_stmt(75)
+               case_stmt(76) case_stmt(77) case_stmt(78) case_stmt(79)
+               case_stmt(80) case_stmt(81) case_stmt(82) case_stmt(83)
+               case_stmt(84) case_stmt(85) case_stmt(86) case_stmt(87)
+               case_stmt(88) case_stmt(89) case_stmt(90) case_stmt(91)
+               case_stmt(92) case_stmt(93) case_stmt(94) case_stmt(95)
+               case_stmt(96) case_stmt(97) case_stmt(98) case_stmt(99)
+               #undef case_stmt
+               default : return error_node();
+            }
+         }
+
+         template <typename Allocator,
+                   template <typename, typename> class Sequence>
+         inline expression_node_ptr const_optimise_varargfunc(const details::operator_type& operation, Sequence<expression_node_ptr,Allocator>& arg_list)
+         {
+            expression_node_ptr temp_node = error_node();
+
+            switch (operation)
+            {
+               #define case_stmt(op0,op1)                                                 \
+               case op0 : temp_node = node_allocator_->                                   \
+                                         allocate<details::vararg_node<Type,op1<Type> > > \
+                                            (arg_list);                                   \
+                          break;                                                          \
+
+               case_stmt(details::e_sum   , details::vararg_add_op  )
+               case_stmt(details::e_prod  , details::vararg_mul_op  )
+               case_stmt(details::e_avg   , details::vararg_avg_op  )
+               case_stmt(details::e_min   , details::vararg_min_op  )
+               case_stmt(details::e_max   , details::vararg_max_op  )
+               case_stmt(details::e_mand  , details::vararg_mand_op )
+               case_stmt(details::e_mor   , details::vararg_mor_op  )
+               case_stmt(details::e_multi , details::vararg_multi_op)
+               #undef case_stmt
+               default : return error_node();
+            }
+
+            const T v = temp_node->value();
+
+            details::free_node(*node_allocator_,temp_node);
+
+            return node_allocator_->allocate<literal_node_t>(v);
+         }
+
+         inline bool special_one_parameter_vararg(const details::operator_type& operation) const
+         {
+            return (
+                     (details::e_sum  == operation) ||
+                     (details::e_prod == operation) ||
+                     (details::e_avg  == operation) ||
+                     (details::e_min  == operation) ||
+                     (details::e_max  == operation)
+                   );
+         }
+
+         template <typename Allocator,
+                   template <typename, typename> class Sequence>
+         inline expression_node_ptr varnode_optimise_varargfunc(const details::operator_type& operation, Sequence<expression_node_ptr,Allocator>& arg_list)
+         {
+            switch (operation)
+            {
+               #define case_stmt(op0,op1)                                                   \
+               case op0 : return node_allocator_->                                          \
+                             allocate<details::vararg_varnode<Type,op1<Type> > >(arg_list); \
+
+               case_stmt(details::e_sum   , details::vararg_add_op  )
+               case_stmt(details::e_prod  , details::vararg_mul_op  )
+               case_stmt(details::e_avg   , details::vararg_avg_op  )
+               case_stmt(details::e_min   , details::vararg_min_op  )
+               case_stmt(details::e_max   , details::vararg_max_op  )
+               case_stmt(details::e_mand  , details::vararg_mand_op )
+               case_stmt(details::e_mor   , details::vararg_mor_op  )
+               case_stmt(details::e_multi , details::vararg_multi_op)
+               #undef case_stmt
+               default : return error_node();
+            }
+         }
+
+         template <typename Allocator,
+                   template <typename, typename> class Sequence>
+         inline expression_node_ptr vectorize_func(const details::operator_type& operation, Sequence<expression_node_ptr,Allocator>& arg_list)
+         {
+            if (1 == arg_list.size())
+            {
+               switch (operation)
+               {
+                  #define case_stmt(op0,op1)                                                      \
+                  case op0 : return node_allocator_->                                             \
+                                allocate<details::vectorize_node<Type,op1<Type> > >(arg_list[0]); \
+
+                  case_stmt(details::e_sum  , details::vec_add_op)
+                  case_stmt(details::e_prod , details::vec_mul_op)
+                  case_stmt(details::e_avg  , details::vec_avg_op)
+                  case_stmt(details::e_min  , details::vec_min_op)
+                  case_stmt(details::e_max  , details::vec_max_op)
+                  #undef case_stmt
+                  default : return error_node();
+               }
+            }
+            else
+               return error_node();
+         }
+
+         template <typename Allocator,
+                   template <typename, typename> class Sequence>
+         inline expression_node_ptr vararg_function(const details::operator_type& operation, Sequence<expression_node_ptr,Allocator>& arg_list)
+         {
+            if (!all_nodes_valid(arg_list))
+            {
+               details::free_all_nodes(*node_allocator_,arg_list);
+
+               return error_node();
+            }
+            else if (is_constant_foldable(arg_list))
+               return const_optimise_varargfunc(operation,arg_list);
+            else if ((arg_list.size() == 1) && details::is_ivector_node(arg_list[0]))
+               return vectorize_func(operation,arg_list);
+            else if ((arg_list.size() == 1) && special_one_parameter_vararg(operation))
+               return arg_list[0];
+            else if (all_nodes_variables(arg_list))
+               return varnode_optimise_varargfunc(operation,arg_list);
+
+            #ifndef exprtk_disable_string_capabilities
+            if (details::e_smulti == operation)
+            {
+               return node_allocator_->
+                 allocate<details::str_vararg_node<Type,details::vararg_multi_op<Type> > >(arg_list);
+            }
+            else
+            #endif
+            {
+               switch (operation)
+               {
+                  #define case_stmt(op0,op1)                                                \
+                  case op0 : return node_allocator_->                                       \
+                                allocate<details::vararg_node<Type,op1<Type> > >(arg_list); \
+
+                  case_stmt(details::e_sum   , details::vararg_add_op  )
+                  case_stmt(details::e_prod  , details::vararg_mul_op  )
+                  case_stmt(details::e_avg   , details::vararg_avg_op  )
+                  case_stmt(details::e_min   , details::vararg_min_op  )
+                  case_stmt(details::e_max   , details::vararg_max_op  )
+                  case_stmt(details::e_mand  , details::vararg_mand_op )
+                  case_stmt(details::e_mor   , details::vararg_mor_op  )
+                  case_stmt(details::e_multi , details::vararg_multi_op)
+                  #undef case_stmt
+                  default : return error_node();
+               }
+            }
+         }
+
+         template <std::size_t N>
+         inline expression_node_ptr function(ifunction_t* f, expression_node_ptr (&b)[N])
+         {
+            typedef typename details::function_N_node<T,ifunction_t,N> function_N_node_t;
+            expression_node_ptr result = synthesize_expression<function_N_node_t,N>(f,b);
+
+            if (0 == result)
+               return error_node();
+            else
+            {
+               // Can the function call be completely optimised?
+               if (details::is_constant_node(result))
+                  return result;
+               else if (!all_nodes_valid(b))
+                  return error_node();
+               else if (N != f->param_count)
+               {
+                  details::free_all_nodes(*node_allocator_,b);
+
+                  return error_node();
+               }
+
+               function_N_node_t* func_node_ptr = static_cast<function_N_node_t*>(result);
+
+               if (func_node_ptr->init_branches(b))
+                  return result;
+               else
+               {
+                  details::free_all_nodes(*node_allocator_,b);
+
+                  return error_node();
+               }
+            }
+         }
+
+         inline expression_node_ptr function(ifunction_t* f)
+         {
+            typedef typename details::function_N_node<Type,ifunction_t,0> function_N_node_t;
+            return node_allocator_->allocate<function_N_node_t>(f);
+         }
+
+         inline expression_node_ptr vararg_function_call(ivararg_function_t* vaf,
+                                                         std::vector<expression_node_ptr>& arg_list)
+         {
+            if (!all_nodes_valid(arg_list))
+            {
+               details::free_all_nodes(*node_allocator_,arg_list);
+
+               return error_node();
+            }
+
+            typedef details::vararg_function_node<Type,ivararg_function_t> alloc_type;
+
+            expression_node_ptr result = node_allocator_->allocate<alloc_type>(vaf,arg_list);
+
+            if (
+                 !arg_list.empty()        &&
+                 !vaf->has_side_effects() &&
+                 is_constant_foldable(arg_list)
+               )
+            {
+               const Type v = result->value();
+               details::free_node(*node_allocator_,result);
+               result = node_allocator_->allocate<literal_node_t>(v);
+            }
+
+            parser_->state_.activate_side_effect("vararg_function_call()");
+
+            return result;
+         }
+
+         inline expression_node_ptr generic_function_call(igeneric_function_t* gf,
+                                                          std::vector<expression_node_ptr>& arg_list,
+                                                          const std::size_t& param_seq_index = std::numeric_limits<std::size_t>::max())
+         {
+            if (!all_nodes_valid(arg_list))
+            {
+               details::free_all_nodes(*node_allocator_,arg_list);
+               return error_node();
+            }
+
+            typedef details::generic_function_node     <Type,igeneric_function_t> alloc_type1;
+            typedef details::multimode_genfunction_node<Type,igeneric_function_t> alloc_type2;
+
+            const std::size_t no_psi = std::numeric_limits<std::size_t>::max();
+
+            expression_node_ptr result = error_node();
+
+            if (no_psi == param_seq_index)
+               result = node_allocator_->allocate<alloc_type1>(arg_list,gf);
+            else
+               result = node_allocator_->allocate<alloc_type2>(gf, param_seq_index, arg_list);
+
+            alloc_type1* genfunc_node_ptr = static_cast<alloc_type1*>(result);
+
+            if (
+                 !arg_list.empty()                  &&
+                 !gf->has_side_effects()            &&
+                 parser_->state_.type_check_enabled &&
+                 is_constant_foldable(arg_list)
+               )
+            {
+               genfunc_node_ptr->init_branches();
+
+               const Type v = result->value();
+
+               details::free_node(*node_allocator_,result);
+
+               return node_allocator_->allocate<literal_node_t>(v);
+            }
+            else if (genfunc_node_ptr->init_branches())
+            {
+               parser_->state_.activate_side_effect("generic_function_call()");
+
+               return result;
+            }
+            else
+            {
+               details::free_node(*node_allocator_, result);
+               details::free_all_nodes(*node_allocator_, arg_list);
+
+               return error_node();
+            }
+         }
+
+         #ifndef exprtk_disable_string_capabilities
+         inline expression_node_ptr string_function_call(igeneric_function_t* gf,
+                                                         std::vector<expression_node_ptr>& arg_list,
+                                                         const std::size_t& param_seq_index = std::numeric_limits<std::size_t>::max())
+         {
+            if (!all_nodes_valid(arg_list))
+            {
+               details::free_all_nodes(*node_allocator_,arg_list);
+               return error_node();
+            }
+
+            typedef details::string_function_node      <Type,igeneric_function_t> alloc_type1;
+            typedef details::multimode_strfunction_node<Type,igeneric_function_t> alloc_type2;
+
+            const std::size_t no_psi = std::numeric_limits<std::size_t>::max();
+
+            expression_node_ptr result = error_node();
+
+            if (no_psi == param_seq_index)
+               result = node_allocator_->allocate<alloc_type1>(gf,arg_list);
+            else
+               result = node_allocator_->allocate<alloc_type2>(gf, param_seq_index, arg_list);
+
+            alloc_type1* strfunc_node_ptr = static_cast<alloc_type1*>(result);
+
+            if (
+                 !arg_list.empty()       &&
+                 !gf->has_side_effects() &&
+                 is_constant_foldable(arg_list)
+               )
+            {
+               strfunc_node_ptr->init_branches();
+
+               const Type v = result->value();
+
+               details::free_node(*node_allocator_,result);
+
+               return node_allocator_->allocate<literal_node_t>(v);
+            }
+            else if (strfunc_node_ptr->init_branches())
+            {
+               parser_->state_.activate_side_effect("string_function_call()");
+
+               return result;
+            }
+            else
+            {
+               details::free_node     (*node_allocator_,result  );
+               details::free_all_nodes(*node_allocator_,arg_list);
+
+               return error_node();
+            }
+         }
+         #endif
+
+         #ifndef exprtk_disable_return_statement
+         inline expression_node_ptr return_call(std::vector<expression_node_ptr>& arg_list)
+         {
+            if (!all_nodes_valid(arg_list))
+            {
+               details::free_all_nodes(*node_allocator_,arg_list);
+               return error_node();
+            }
+
+            typedef details::return_node<Type> alloc_type;
+
+            expression_node_ptr result = node_allocator_->
+                                            allocate_rr<alloc_type>(arg_list,parser_->results_ctx());
+
+            alloc_type* return_node_ptr = static_cast<alloc_type*>(result);
+
+            if (return_node_ptr->init_branches())
+            {
+               parser_->state_.activate_side_effect("return_call()");
+
+               return result;
+            }
+            else
+            {
+               details::free_node     (*node_allocator_,result  );
+               details::free_all_nodes(*node_allocator_,arg_list);
+
+               return error_node();
+            }
+         }
+
+         inline expression_node_ptr return_envelope(expression_node_ptr body,
+                                                    results_context_t* rc,
+                                                    bool*& return_invoked)
+         {
+            typedef details::return_envelope_node<Type> alloc_type;
+
+            expression_node_ptr result = node_allocator_->
+                                            allocate_cr<alloc_type>(body,(*rc));
+
+            return_invoked = static_cast<alloc_type*>(result)->retinvk_ptr();
+
+            return result;
+         }
+         #else
+         inline expression_node_ptr return_call(std::vector<expression_node_ptr>&)
+         {
+            return error_node();
+         }
+
+         inline expression_node_ptr return_envelope(expression_node_ptr,
+                                                    results_context_t*,
+                                                    bool*&)
+         {
+            return error_node();
+         }
+         #endif
+
+         inline expression_node_ptr vector_element(const std::string& symbol,
+                                                   vector_holder_ptr vector_base,
+                                                   expression_node_ptr index)
+         {
+            expression_node_ptr result = error_node();
+
+            if (details::is_constant_node(index))
+            {
+               std::size_t i = static_cast<std::size_t>(details::numeric::to_int64(index->value()));
+
+               details::free_node(*node_allocator_,index);
+
+               if (vector_base->rebaseable())
+               {
+                  return node_allocator_->allocate<rebasevector_celem_node_t>(i,vector_base);
+               }
+
+               scope_element& se = parser_->sem_.get_element(symbol,i);
+
+               if (se.index == i)
+               {
+                  result = se.var_node;
+               }
+               else
+               {
+                  scope_element nse;
+                  nse.name      = symbol;
+                  nse.active    = true;
+                  nse.ref_count = 1;
+                  nse.type      = scope_element::e_vecelem;
+                  nse.index     = i;
+                  nse.depth     = parser_->state_.scope_depth;
+                  nse.data      = 0;
+                  nse.var_node  = node_allocator_->allocate<variable_node_t>((*(*vector_base)[i]));
+
+                  if (!parser_->sem_.add_element(nse))
+                  {
+                     parser_->set_synthesis_error("Failed to add new local vector element to SEM [1]");
+
+                     parser_->sem_.free_element(nse);
+
+                     result = error_node();
+                  }
+
+                  exprtk_debug(("vector_element() - INFO - Added new local vector element: %s\n",nse.name.c_str()));
+
+                  parser_->state_.activate_side_effect("vector_element()");
+
+                  result = nse.var_node;
+               }
+            }
+            else if (vector_base->rebaseable())
+               result = node_allocator_->allocate<rebasevector_elem_node_t>(index,vector_base);
+            else
+               result = node_allocator_->allocate<vector_elem_node_t>(index,vector_base);
+
+            return result;
+         }
+
+      private:
+
+         template <std::size_t N, typename NodePtr>
+         inline bool is_constant_foldable(NodePtr (&b)[N]) const
+         {
+            for (std::size_t i = 0; i < N; ++i)
+            {
+               if (0 == b[i])
+                  return false;
+               else if (!details::is_constant_node(b[i]))
+                  return false;
+            }
+
+            return true;
+         }
+
+         template <typename NodePtr,
+                   typename Allocator,
+                   template <typename, typename> class Sequence>
+         inline bool is_constant_foldable(const Sequence<NodePtr,Allocator>& b) const
+         {
+            for (std::size_t i = 0; i < b.size(); ++i)
+            {
+               if (0 == b[i])
+                  return false;
+               else if (!details::is_constant_node(b[i]))
+                  return false;
+            }
+
+            return true;
+         }
+
+         void lodge_assignment(symbol_type cst, expression_node_ptr node)
+         {
+            parser_->state_.activate_side_effect("lodge_assignment()");
+
+            if (!parser_->dec_.collect_assignments())
+               return;
+
+            std::string symbol_name;
+
+            switch (cst)
+            {
+               case e_st_variable : symbol_name = parser_->symtab_store_
+                                                     .get_variable_name(node);
+                                    break;
+
+               #ifndef exprtk_disable_string_capabilities
+               case e_st_string   : symbol_name = parser_->symtab_store_
+                                                     .get_stringvar_name(node);
+                                    break;
+               #endif
+
+               case e_st_vector   : {
+                                       typedef details::vector_holder<T> vector_holder_t;
+
+                                       vector_holder_t& vh = static_cast<vector_node_t*>(node)->vec_holder();
+
+                                       symbol_name = parser_->symtab_store_.get_vector_name(&vh);
+                                    }
+                                    break;
+
+               case e_st_vecelem  : {
+                                       typedef details::vector_holder<T> vector_holder_t;
+
+                                       vector_holder_t& vh = static_cast<vector_elem_node_t*>(node)->vec_holder();
+
+                                       symbol_name = parser_->symtab_store_.get_vector_name(&vh);
+
+                                       cst = e_st_vector;
+                                    }
+                                    break;
+
+               default            : return;
+            }
+
+            if (!symbol_name.empty())
+            {
+               parser_->dec_.add_assignment(symbol_name,cst);
+            }
+         }
+
+         inline expression_node_ptr synthesize_assignment_expression(const details::operator_type& operation, expression_node_ptr (&branch)[2])
+         {
+            if (details::is_variable_node(branch[0]))
+            {
+               lodge_assignment(e_st_variable,branch[0]);
+
+               return synthesize_expression<assignment_node_t,2>(operation,branch);
+            }
+            else if (details::is_vector_elem_node(branch[0]))
+            {
+               lodge_assignment(e_st_vecelem,branch[0]);
+
+               return synthesize_expression<assignment_vec_elem_node_t, 2>(operation, branch);
+            }
+            else if (details::is_rebasevector_elem_node(branch[0]))
+            {
+               lodge_assignment(e_st_vecelem,branch[0]);
+
+               return synthesize_expression<assignment_rebasevec_elem_node_t, 2>(operation, branch);
+            }
+            else if (details::is_rebasevector_celem_node(branch[0]))
+            {
+               lodge_assignment(e_st_vecelem,branch[0]);
+
+               return synthesize_expression<assignment_rebasevec_celem_node_t, 2>(operation, branch);
+            }
+            #ifndef exprtk_disable_string_capabilities
+            else if (details::is_string_node(branch[0]))
+            {
+               lodge_assignment(e_st_string,branch[0]);
+
+               return synthesize_expression<assignment_string_node_t,2>(operation, branch);
+            }
+            else if (details::is_string_range_node(branch[0]))
+            {
+               lodge_assignment(e_st_string,branch[0]);
+
+               return synthesize_expression<assignment_string_range_node_t,2>(operation, branch);
+            }
+            #endif
+            else if (details::is_vector_node(branch[0]))
+            {
+               lodge_assignment(e_st_vector,branch[0]);
+
+               if (details::is_ivector_node(branch[1]))
+                  return synthesize_expression<assignment_vecvec_node_t,2>(operation, branch);
+              else
+                  return synthesize_expression<assignment_vec_node_t,2>(operation, branch);
+            }
+            else
+            {
+               parser_->set_synthesis_error("Invalid assignment operation.[1]");
+
+               return error_node();
+            }
+         }
+
+         inline expression_node_ptr synthesize_assignment_operation_expression(const details::operator_type& operation,
+                                                                               expression_node_ptr (&branch)[2])
+         {
+            if (details::is_variable_node(branch[0]))
+            {
+               lodge_assignment(e_st_variable,branch[0]);
+
+               switch (operation)
+               {
+                  #define case_stmt(op0,op1)                                                                  \
+                  case op0 : return node_allocator_->                                                         \
+                                template allocate_rrr<typename details::assignment_op_node<Type,op1<Type> > > \
+                                   (operation, branch[0], branch[1]);                                         \
+
+                  case_stmt(details::e_addass,details::add_op)
+                  case_stmt(details::e_subass,details::sub_op)
+                  case_stmt(details::e_mulass,details::mul_op)
+                  case_stmt(details::e_divass,details::div_op)
+                  case_stmt(details::e_modass,details::mod_op)
+                  #undef case_stmt
+                  default : return error_node();
+               }
+            }
+            else if (details::is_vector_elem_node(branch[0]))
+            {
+               lodge_assignment(e_st_vecelem,branch[0]);
+
+               switch (operation)
+               {
+                  #define case_stmt(op0,op1)                                                                            \
+                  case op0 : return node_allocator_->                                                                   \
+                                 template allocate_rrr<typename details::assignment_vec_elem_op_node<Type,op1<Type> > > \
+                                    (operation, branch[0], branch[1]);                                                  \
+
+                  case_stmt(details::e_addass,details::add_op)
+                  case_stmt(details::e_subass,details::sub_op)
+                  case_stmt(details::e_mulass,details::mul_op)
+                  case_stmt(details::e_divass,details::div_op)
+                  case_stmt(details::e_modass,details::mod_op)
+                  #undef case_stmt
+                  default : return error_node();
+               }
+            }
+            else if (details::is_rebasevector_elem_node(branch[0]))
+            {
+               lodge_assignment(e_st_vecelem,branch[0]);
+
+               switch (operation)
+               {
+                  #define case_stmt(op0,op1)                                                                                  \
+                  case op0 : return node_allocator_->                                                                         \
+                                 template allocate_rrr<typename details::assignment_rebasevec_elem_op_node<Type,op1<Type> > > \
+                                    (operation, branch[0], branch[1]);                                                        \
+
+                  case_stmt(details::e_addass,details::add_op)
+                  case_stmt(details::e_subass,details::sub_op)
+                  case_stmt(details::e_mulass,details::mul_op)
+                  case_stmt(details::e_divass,details::div_op)
+                  case_stmt(details::e_modass,details::mod_op)
+                  #undef case_stmt
+                  default : return error_node();
+               }
+            }
+            else if (details::is_rebasevector_celem_node(branch[0]))
+            {
+               lodge_assignment(e_st_vecelem,branch[0]);
+
+               switch (operation)
+               {
+                  #define case_stmt(op0,op1)                                                                                   \
+                  case op0 : return node_allocator_->                                                                          \
+                                 template allocate_rrr<typename details::assignment_rebasevec_celem_op_node<Type,op1<Type> > > \
+                                    (operation, branch[0], branch[1]);                                                         \
+
+                  case_stmt(details::e_addass,details::add_op)
+                  case_stmt(details::e_subass,details::sub_op)
+                  case_stmt(details::e_mulass,details::mul_op)
+                  case_stmt(details::e_divass,details::div_op)
+                  case_stmt(details::e_modass,details::mod_op)
+                  #undef case_stmt
+                  default : return error_node();
+               }
+            }
+            else if (details::is_vector_node(branch[0]))
+            {
+               lodge_assignment(e_st_vector,branch[0]);
+
+               if (details::is_ivector_node(branch[1]))
+               {
+                  switch (operation)
+                  {
+                     #define case_stmt(op0,op1)                                                                         \
+                     case op0 : return node_allocator_->                                                                \
+                                   template allocate_rrr<typename details::assignment_vecvec_op_node<Type,op1<Type> > > \
+                                      (operation, branch[0], branch[1]);                                                \
+
+                     case_stmt(details::e_addass,details::add_op)
+                     case_stmt(details::e_subass,details::sub_op)
+                     case_stmt(details::e_mulass,details::mul_op)
+                     case_stmt(details::e_divass,details::div_op)
+                     case_stmt(details::e_modass,details::mod_op)
+                     #undef case_stmt
+                     default : return error_node();
+                  }
+               }
+               else
+               {
+                  switch (operation)
+                  {
+                     #define case_stmt(op0,op1)                                                                      \
+                     case op0 : return node_allocator_->                                                             \
+                                   template allocate_rrr<typename details::assignment_vec_op_node<Type,op1<Type> > > \
+                                      (operation, branch[0], branch[1]);                                             \
+
+                     case_stmt(details::e_addass,details::add_op)
+                     case_stmt(details::e_subass,details::sub_op)
+                     case_stmt(details::e_mulass,details::mul_op)
+                     case_stmt(details::e_divass,details::div_op)
+                     case_stmt(details::e_modass,details::mod_op)
+                     #undef case_stmt
+                     default : return error_node();
+                  }
+               }
+            }
+            #ifndef exprtk_disable_string_capabilities
+            else if (
+                      (details::e_addass == operation) &&
+                      details::is_string_node(branch[0])
+                    )
+            {
+               typedef details::assignment_string_node<T,details::asn_addassignment> addass_t;
+
+               lodge_assignment(e_st_string,branch[0]);
+
+               return synthesize_expression<addass_t,2>(operation,branch);
+            }
+            #endif
+            else
+            {
+               parser_->set_synthesis_error("Invalid assignment operation[2]");
+
+               return error_node();
+            }
+         }
+
+         inline expression_node_ptr synthesize_veceqineqlogic_operation_expression(const details::operator_type& operation,
+                                                                                   expression_node_ptr (&branch)[2])
+         {
+            const bool is_b0_ivec = details::is_ivector_node(branch[0]);
+            const bool is_b1_ivec = details::is_ivector_node(branch[1]);
+
+            #define batch_eqineq_logic_case                \
+            case_stmt(details::   e_lt, details::   lt_op) \
+            case_stmt(details::  e_lte, details::  lte_op) \
+            case_stmt(details::   e_gt, details::   gt_op) \
+            case_stmt(details::  e_gte, details::  gte_op) \
+            case_stmt(details::   e_eq, details::   eq_op) \
+            case_stmt(details::   e_ne, details::   ne_op) \
+            case_stmt(details::e_equal, details::equal_op) \
+            case_stmt(details::  e_and, details::  and_op) \
+            case_stmt(details:: e_nand, details:: nand_op) \
+            case_stmt(details::   e_or, details::   or_op) \
+            case_stmt(details::  e_nor, details::  nor_op) \
+            case_stmt(details::  e_xor, details::  xor_op) \
+            case_stmt(details:: e_xnor, details:: xnor_op) \
+
+            if (is_b0_ivec && is_b1_ivec)
+            {
+               switch (operation)
+               {
+                  #define case_stmt(op0,op1)                                                                     \
+                  case op0 : return node_allocator_->                                                            \
+                                template allocate_rrr<typename details::vec_binop_vecvec_node<Type,op1<Type> > > \
+                                   (operation, branch[0], branch[1]);                                            \
+
+                  batch_eqineq_logic_case
+                  #undef case_stmt
+                  default : return error_node();
+               }
+            }
+            else if (is_b0_ivec && !is_b1_ivec)
+            {
+               switch (operation)
+               {
+                  #define case_stmt(op0,op1)                                                                     \
+                  case op0 : return node_allocator_->                                                            \
+                                template allocate_rrr<typename details::vec_binop_vecval_node<Type,op1<Type> > > \
+                                   (operation, branch[0], branch[1]);                                            \
+
+                  batch_eqineq_logic_case
+                  #undef case_stmt
+                  default : return error_node();
+               }
+            }
+            else if (!is_b0_ivec && is_b1_ivec)
+            {
+               switch (operation)
+               {
+                  #define case_stmt(op0,op1)                                                                     \
+                  case op0 : return node_allocator_->                                                            \
+                                template allocate_rrr<typename details::vec_binop_valvec_node<Type,op1<Type> > > \
+                                   (operation, branch[0], branch[1]);                                            \
+
+                  batch_eqineq_logic_case
+                  #undef case_stmt
+                  default : return error_node();
+               }
+            }
+            else
+               return error_node();
+
+            #undef batch_eqineq_logic_case
+         }
+
+         inline expression_node_ptr synthesize_vecarithmetic_operation_expression(const details::operator_type& operation,
+                                                                                  expression_node_ptr (&branch)[2])
+         {
+            const bool is_b0_ivec = details::is_ivector_node(branch[0]);
+            const bool is_b1_ivec = details::is_ivector_node(branch[1]);
+
+            #define vector_ops                        \
+            case_stmt(details::e_add,details::add_op) \
+            case_stmt(details::e_sub,details::sub_op) \
+            case_stmt(details::e_mul,details::mul_op) \
+            case_stmt(details::e_div,details::div_op) \
+            case_stmt(details::e_mod,details::mod_op) \
+
+            if (is_b0_ivec && is_b1_ivec)
+            {
+               switch (operation)
+               {
+                  #define case_stmt(op0,op1)                                                                     \
+                  case op0 : return node_allocator_->                                                            \
+                                template allocate_rrr<typename details::vec_binop_vecvec_node<Type,op1<Type> > > \
+                                   (operation, branch[0], branch[1]);                                            \
+
+                  vector_ops
+                  case_stmt(details::e_pow,details:: pow_op)
+                  #undef case_stmt
+                  default : return error_node();
+               }
+            }
+            else if (is_b0_ivec && !is_b1_ivec)
+            {
+               switch (operation)
+               {
+                  #define case_stmt(op0,op1)                                                                     \
+                  case op0 : return node_allocator_->                                                            \
+                                template allocate_rrr<typename details::vec_binop_vecval_node<Type,op1<Type> > > \
+                                   (operation, branch[0], branch[1]);                                            \
+
+                  vector_ops
+                  case_stmt(details::e_pow,details:: pow_op)
+                  #undef case_stmt
+                  default : return error_node();
+               }
+            }
+            else if (!is_b0_ivec && is_b1_ivec)
+            {
+               switch (operation)
+               {
+                  #define case_stmt(op0,op1)                                                                     \
+                  case op0 : return node_allocator_->                                                            \
+                                template allocate_rrr<typename details::vec_binop_valvec_node<Type,op1<Type> > > \
+                                   (operation, branch[0], branch[1]);                                            \
+
+                  vector_ops
+                  #undef case_stmt
+                  default : return error_node();
+               }
+            }
+            else
+               return error_node();
+
+            #undef vector_ops
+         }
+
+         inline expression_node_ptr synthesize_swap_expression(expression_node_ptr (&branch)[2])
+         {
+            const bool v0_is_ivar = details::is_ivariable_node(branch[0]);
+            const bool v1_is_ivar = details::is_ivariable_node(branch[1]);
+
+            const bool v0_is_ivec = details::is_ivector_node  (branch[0]);
+            const bool v1_is_ivec = details::is_ivector_node  (branch[1]);
+
+            #ifndef exprtk_disable_string_capabilities
+            const bool v0_is_str = details::is_generally_string_node(branch[0]);
+            const bool v1_is_str = details::is_generally_string_node(branch[1]);
+            #endif
+
+            expression_node_ptr result = error_node();
+
+            if (v0_is_ivar && v1_is_ivar)
+            {
+               typedef details::variable_node<T>* variable_node_ptr;
+
+               variable_node_ptr v0 = variable_node_ptr(0);
+               variable_node_ptr v1 = variable_node_ptr(0);
+
+               if (
+                    (0 != (v0 = dynamic_cast<variable_node_ptr>(branch[0]))) &&
+                    (0 != (v1 = dynamic_cast<variable_node_ptr>(branch[1])))
+                  )
+               {
+                  result = node_allocator_->allocate<details::swap_node<T> >(v0,v1);
+               }
+               else
+                  result = node_allocator_->allocate<details::swap_generic_node<T> >(branch[0],branch[1]);
+            }
+            else if (v0_is_ivec && v1_is_ivec)
+            {
+               result = node_allocator_->allocate<details::swap_vecvec_node<T> >(branch[0],branch[1]);
+            }
+            #ifndef exprtk_disable_string_capabilities
+            else if (v0_is_str && v1_is_str)
+            {
+               if (is_string_node(branch[0]) && is_string_node(branch[1]))
+                  result = node_allocator_->allocate<details::swap_string_node<T> >
+                                               (branch[0], branch[1]);
+               else
+                  result = node_allocator_->allocate<details::swap_genstrings_node<T> >
+                                               (branch[0], branch[1]);
+            }
+            #endif
+            else
+            {
+               parser_->set_synthesis_error("Only variables, strings, vectors or vector elements can be swapped");
+
+               return error_node();
+            }
+
+            parser_->state_.activate_side_effect("synthesize_swap_expression()");
+
+            return result;
+         }
+
+         #ifndef exprtk_disable_sc_andor
+         inline expression_node_ptr synthesize_shortcircuit_expression(const details::operator_type& operation, expression_node_ptr (&branch)[2])
+         {
+            expression_node_ptr result = error_node();
+
+            if (details::is_constant_node(branch[0]))
+            {
+               if (
+                    (details::e_scand == operation) &&
+                    std::equal_to<T>()(T(0),branch[0]->value())
+                  )
+                  result = node_allocator_->allocate_c<literal_node_t>(T(0));
+               else if (
+                         (details::e_scor == operation) &&
+                         std::not_equal_to<T>()(T(0),branch[0]->value())
+                       )
+                  result = node_allocator_->allocate_c<literal_node_t>(T(1));
+            }
+
+            if (details::is_constant_node(branch[1]) && (0 == result))
+            {
+               if (
+                    (details::e_scand == operation) &&
+                    std::equal_to<T>()(T(0),branch[1]->value())
+                  )
+                  result = node_allocator_->allocate_c<literal_node_t>(T(0));
+               else if (
+                         (details::e_scor == operation) &&
+                         std::not_equal_to<T>()(T(0),branch[1]->value())
+                       )
+                  result = node_allocator_->allocate_c<literal_node_t>(T(1));
+            }
+
+            if (result)
+            {
+               free_node(*node_allocator_, branch[0]);
+               free_node(*node_allocator_, branch[1]);
+
+               return result;
+            }
+            else if (details::e_scand == operation)
+            {
+               return synthesize_expression<scand_node_t,2>(operation, branch);
+            }
+            else if (details::e_scor == operation)
+            {
+               return synthesize_expression<scor_node_t,2>(operation, branch);
+            }
+            else
+               return error_node();
+         }
+         #else
+         inline expression_node_ptr synthesize_shortcircuit_expression(const details::operator_type&, expression_node_ptr (&)[2])
+         {
+            return error_node();
+         }
+         #endif
+
+         #define basic_opr_switch_statements        \
+         case_stmt(details::e_add, details::add_op) \
+         case_stmt(details::e_sub, details::sub_op) \
+         case_stmt(details::e_mul, details::mul_op) \
+         case_stmt(details::e_div, details::div_op) \
+         case_stmt(details::e_mod, details::mod_op) \
+         case_stmt(details::e_pow, details::pow_op) \
+
+         #define extended_opr_switch_statements       \
+         case_stmt(details::  e_lt, details::  lt_op) \
+         case_stmt(details:: e_lte, details:: lte_op) \
+         case_stmt(details::  e_gt, details::  gt_op) \
+         case_stmt(details:: e_gte, details:: gte_op) \
+         case_stmt(details::  e_eq, details::  eq_op) \
+         case_stmt(details::  e_ne, details::  ne_op) \
+         case_stmt(details:: e_and, details:: and_op) \
+         case_stmt(details::e_nand, details::nand_op) \
+         case_stmt(details::  e_or, details::  or_op) \
+         case_stmt(details:: e_nor, details:: nor_op) \
+         case_stmt(details:: e_xor, details:: xor_op) \
+         case_stmt(details::e_xnor, details::xnor_op) \
+
+         #ifndef exprtk_disable_cardinal_pow_optimisation
+         template <typename TType, template <typename, typename> class IPowNode>
+         inline expression_node_ptr cardinal_pow_optimisation_impl(const TType& v, const unsigned int& p)
+         {
+            switch (p)
+            {
+               #define case_stmt(cp)                                                     \
+               case cp : return node_allocator_->                                        \
+                            allocate<IPowNode<T,details::numeric::fast_exp<T,cp> > >(v); \
+
+               case_stmt( 1) case_stmt( 2) case_stmt( 3) case_stmt( 4)
+               case_stmt( 5) case_stmt( 6) case_stmt( 7) case_stmt( 8)
+               case_stmt( 9) case_stmt(10) case_stmt(11) case_stmt(12)
+               case_stmt(13) case_stmt(14) case_stmt(15) case_stmt(16)
+               case_stmt(17) case_stmt(18) case_stmt(19) case_stmt(20)
+               case_stmt(21) case_stmt(22) case_stmt(23) case_stmt(24)
+               case_stmt(25) case_stmt(26) case_stmt(27) case_stmt(28)
+               case_stmt(29) case_stmt(30) case_stmt(31) case_stmt(32)
+               case_stmt(33) case_stmt(34) case_stmt(35) case_stmt(36)
+               case_stmt(37) case_stmt(38) case_stmt(39) case_stmt(40)
+               case_stmt(41) case_stmt(42) case_stmt(43) case_stmt(44)
+               case_stmt(45) case_stmt(46) case_stmt(47) case_stmt(48)
+               case_stmt(49) case_stmt(50) case_stmt(51) case_stmt(52)
+               case_stmt(53) case_stmt(54) case_stmt(55) case_stmt(56)
+               case_stmt(57) case_stmt(58) case_stmt(59) case_stmt(60)
+               #undef case_stmt
+               default : return error_node();
+            }
+         }
+
+         inline expression_node_ptr cardinal_pow_optimisation(const T& v, const T& c)
+         {
+            const bool not_recipricol = (c >= T(0));
+            const unsigned int p = static_cast<unsigned int>(details::numeric::to_int32(details::numeric::abs(c)));
+
+            if (0 == p)
+               return node_allocator_->allocate_c<literal_node_t>(T(1));
+            else if (std::equal_to<T>()(T(2),c))
+            {
+               return node_allocator_->
+                  template allocate_rr<typename details::vov_node<Type,details::mul_op<Type> > >(v,v);
+            }
+            else
+            {
+               if (not_recipricol)
+                  return cardinal_pow_optimisation_impl<T,details::ipow_node>(v,p);
+               else
+                  return cardinal_pow_optimisation_impl<T,details::ipowinv_node>(v,p);
+            }
+         }
+
+         inline bool cardinal_pow_optimisable(const details::operator_type& operation, const T& c) const
+         {
+            return (details::e_pow == operation) && (details::numeric::abs(c) <= T(60)) && details::numeric::is_integer(c);
+         }
+
+         inline expression_node_ptr cardinal_pow_optimisation(expression_node_ptr (&branch)[2])
+         {
+            const Type c = static_cast<details::literal_node<Type>*>(branch[1])->value();
+            const bool not_recipricol = (c >= T(0));
+            const unsigned int p = static_cast<unsigned int>(details::numeric::to_int32(details::numeric::abs(c)));
+
+            node_allocator_->free(branch[1]);
+
+            if (0 == p)
+            {
+               details::free_all_nodes(*node_allocator_, branch);
+
+               return node_allocator_->allocate_c<literal_node_t>(T(1));
+            }
+            else if (not_recipricol)
+               return cardinal_pow_optimisation_impl<expression_node_ptr,details::bipow_node>(branch[0],p);
+            else
+               return cardinal_pow_optimisation_impl<expression_node_ptr,details::bipowninv_node>(branch[0],p);
+         }
+         #else
+         inline expression_node_ptr cardinal_pow_optimisation(T&, const T&)
+         {
+            return error_node();
+         }
+
+         inline bool cardinal_pow_optimisable(const details::operator_type&, const T&)
+         {
+            return false;
+         }
+
+         inline expression_node_ptr cardinal_pow_optimisation(expression_node_ptr(&)[2])
+         {
+            return error_node();
+         }
+         #endif
+
+         struct synthesize_binary_ext_expression
+         {
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               const bool left_neg  = is_neg_unary_node(branch[0]);
+               const bool right_neg = is_neg_unary_node(branch[1]);
+
+               if (left_neg && right_neg)
+               {
+                  if (
+                       (details::e_add == operation) ||
+                       (details::e_sub == operation) ||
+                       (details::e_mul == operation) ||
+                       (details::e_div == operation)
+                     )
+                  {
+                     if (
+                          !expr_gen.parser_->simplify_unary_negation_branch(branch[0]) ||
+                          !expr_gen.parser_->simplify_unary_negation_branch(branch[1])
+                        )
+                     {
+                        details::free_all_nodes(*expr_gen.node_allocator_,branch);
+
+                        return error_node();
+                     }
+                  }
+
+                  switch (operation)
+                  {
+                                           // -f(x + 1) + -g(y + 1) --> -(f(x + 1) + g(y + 1))
+                     case details::e_add : return expr_gen(details::e_neg,
+                                              expr_gen.node_allocator_->
+                                                 template allocate<typename details::binary_ext_node<Type,details::add_op<Type> > >
+                                                    (branch[0],branch[1]));
+
+                                           // -f(x + 1) - -g(y + 1) --> g(y + 1) - f(x + 1)
+                     case details::e_sub : return expr_gen.node_allocator_->
+                                              template allocate<typename details::binary_ext_node<Type,details::sub_op<Type> > >
+                                                 (branch[1],branch[0]);
+
+                     default             : break;
+                  }
+               }
+               else if (left_neg && !right_neg)
+               {
+                  if (
+                       (details::e_add == operation) ||
+                       (details::e_sub == operation) ||
+                       (details::e_mul == operation) ||
+                       (details::e_div == operation)
+                     )
+                  {
+                     if (!expr_gen.parser_->simplify_unary_negation_branch(branch[0]))
+                     {
+                        details::free_all_nodes(*expr_gen.node_allocator_,branch);
+
+                        return error_node();
+                     }
+
+                     switch (operation)
+                     {
+                                              // -f(x + 1) + g(y + 1) --> g(y + 1) - f(x + 1)
+                        case details::e_add : return expr_gen.node_allocator_->
+                                                 template allocate<typename details::binary_ext_node<Type,details::sub_op<Type> > >
+                                                   (branch[1], branch[0]);
+
+                                              // -f(x + 1) - g(y + 1) --> -(f(x + 1) + g(y + 1))
+                        case details::e_sub : return expr_gen(details::e_neg,
+                                                 expr_gen.node_allocator_->
+                                                    template allocate<typename details::binary_ext_node<Type,details::add_op<Type> > >
+                                                       (branch[0], branch[1]));
+
+                                              // -f(x + 1) * g(y + 1) --> -(f(x + 1) * g(y + 1))
+                        case details::e_mul : return expr_gen(details::e_neg,
+                                                 expr_gen.node_allocator_->
+                                                    template allocate<typename details::binary_ext_node<Type,details::mul_op<Type> > >
+                                                       (branch[0], branch[1]));
+
+                                              // -f(x + 1) / g(y + 1) --> -(f(x + 1) / g(y + 1))
+                        case details::e_div : return expr_gen(details::e_neg,
+                                                 expr_gen.node_allocator_->
+                                                    template allocate<typename details::binary_ext_node<Type,details::div_op<Type> > >
+                                                       (branch[0], branch[1]));
+
+                        default             : return error_node();
+                     }
+                  }
+               }
+               else if (!left_neg && right_neg)
+               {
+                  if (
+                       (details::e_add == operation) ||
+                       (details::e_sub == operation) ||
+                       (details::e_mul == operation) ||
+                       (details::e_div == operation)
+                     )
+                  {
+                     if (!expr_gen.parser_->simplify_unary_negation_branch(branch[1]))
+                     {
+                        details::free_all_nodes(*expr_gen.node_allocator_,branch);
+
+                        return error_node();
+                     }
+
+                     switch (operation)
+                     {
+                                              // f(x + 1) + -g(y + 1) --> f(x + 1) - g(y + 1)
+                        case details::e_add : return expr_gen.node_allocator_->
+                                                 template allocate<typename details::binary_ext_node<Type,details::sub_op<Type> > >
+                                                   (branch[0], branch[1]);
+
+                                              // f(x + 1) - - g(y + 1) --> f(x + 1) + g(y + 1)
+                        case details::e_sub : return expr_gen.node_allocator_->
+                                                 template allocate<typename details::binary_ext_node<Type,details::add_op<Type> > >
+                                                   (branch[0], branch[1]);
+
+                                              // f(x + 1) * -g(y + 1) --> -(f(x + 1) * g(y + 1))
+                        case details::e_mul : return expr_gen(details::e_neg,
+                                                 expr_gen.node_allocator_->
+                                                    template allocate<typename details::binary_ext_node<Type,details::mul_op<Type> > >
+                                                       (branch[0], branch[1]));
+
+                                              // f(x + 1) / -g(y + 1) --> -(f(x + 1) / g(y + 1))
+                        case details::e_div : return expr_gen(details::e_neg,
+                                                 expr_gen.node_allocator_->
+                                                    template allocate<typename details::binary_ext_node<Type,details::div_op<Type> > >
+                                                       (branch[0], branch[1]));
+
+                        default             : return error_node();
+                     }
+                  }
+               }
+
+               switch (operation)
+               {
+                  #define case_stmt(op0,op1)                                                           \
+                  case op0 : return expr_gen.node_allocator_->                                         \
+                                template allocate<typename details::binary_ext_node<Type,op1<Type> > > \
+                                   (branch[0], branch[1]);                                             \
+
+                  basic_opr_switch_statements
+                  extended_opr_switch_statements
+                  #undef case_stmt
+                  default : return error_node();
+               }
+            }
+         };
+
+         struct synthesize_vob_expression
+         {
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               const Type& v = static_cast<details::variable_node<Type>*>(branch[0])->ref();
+
+               #ifndef exprtk_disable_enhanced_features
+               if (details::is_sf3ext_node(branch[1]))
+               {
+                  expression_node_ptr result = error_node();
+
+                  const bool synthesis_result =
+                     synthesize_sf4ext_expression::template compile_right<vtype>
+                        (expr_gen, v, operation, branch[1], result);
+
+                  if (synthesis_result)
+                  {
+                     free_node(*expr_gen.node_allocator_,branch[1]);
+                     return result;
+                  }
+               }
+               #endif
+
+               if (
+                    (details::e_mul == operation) ||
+                    (details::e_div == operation)
+                  )
+               {
+                  if (details::is_uv_node(branch[1]))
+                  {
+                     typedef details::uv_base_node<Type>* uvbn_ptr_t;
+
+                     details::operator_type o = static_cast<uvbn_ptr_t>(branch[1])->operation();
+
+                     if (details::e_neg == o)
+                     {
+                        const Type& v1 = static_cast<uvbn_ptr_t>(branch[1])->v();
+
+                        free_node(*expr_gen.node_allocator_,branch[1]);
+
+                        switch (operation)
+                        {
+                           case details::e_mul : return expr_gen(details::e_neg,
+                                                    expr_gen.node_allocator_->
+                                                       template allocate_rr<typename details::
+                                                          vov_node<Type,details::mul_op<Type> > >(v,v1));
+
+                           case details::e_div : return expr_gen(details::e_neg,
+                                                    expr_gen.node_allocator_->
+                                                       template allocate_rr<typename details::
+                                                          vov_node<Type,details::div_op<Type> > >(v,v1));
+
+                           default             : break;
+                        }
+                     }
+                  }
+               }
+
+               switch (operation)
+               {
+                  #define case_stmt(op0,op1)                                                       \
+                  case op0 : return expr_gen.node_allocator_->                                     \
+                                template allocate_rc<typename details::vob_node<Type,op1<Type> > > \
+                                   (v, branch[1]);                                                 \
+
+                  basic_opr_switch_statements
+                  extended_opr_switch_statements
+                  #undef case_stmt
+                  default : return error_node();
+               }
+            }
+         };
+
+         struct synthesize_bov_expression
+         {
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               const Type& v = static_cast<details::variable_node<Type>*>(branch[1])->ref();
+
+               #ifndef exprtk_disable_enhanced_features
+               if (details::is_sf3ext_node(branch[0]))
+               {
+                  expression_node_ptr result = error_node();
+
+                  const bool synthesis_result =
+                     synthesize_sf4ext_expression::template compile_left<vtype>
+                        (expr_gen, v, operation, branch[0], result);
+
+                  if (synthesis_result)
+                  {
+                     free_node(*expr_gen.node_allocator_, branch[0]);
+
+                     return result;
+                  }
+               }
+               #endif
+
+               if (
+                    (details::e_add == operation) ||
+                    (details::e_sub == operation) ||
+                    (details::e_mul == operation) ||
+                    (details::e_div == operation)
+                  )
+               {
+                  if (details::is_uv_node(branch[0]))
+                  {
+                     typedef details::uv_base_node<Type>* uvbn_ptr_t;
+
+                     details::operator_type o = static_cast<uvbn_ptr_t>(branch[0])->operation();
+
+                     if (details::e_neg == o)
+                     {
+                        const Type& v0 = static_cast<uvbn_ptr_t>(branch[0])->v();
+
+                        free_node(*expr_gen.node_allocator_,branch[0]);
+
+                        switch (operation)
+                        {
+                           case details::e_add : return expr_gen.node_allocator_->
+                                                    template allocate_rr<typename details::
+                                                       vov_node<Type,details::sub_op<Type> > >(v,v0);
+
+                           case details::e_sub : return expr_gen(details::e_neg,
+                                                    expr_gen.node_allocator_->
+                                                       template allocate_rr<typename details::
+                                                          vov_node<Type,details::add_op<Type> > >(v0,v));
+
+                           case details::e_mul : return expr_gen(details::e_neg,
+                                                    expr_gen.node_allocator_->
+                                                       template allocate_rr<typename details::
+                                                          vov_node<Type,details::mul_op<Type> > >(v0,v));
+
+                           case details::e_div : return expr_gen(details::e_neg,
+                                                    expr_gen.node_allocator_->
+                                                       template allocate_rr<typename details::
+                                                          vov_node<Type,details::div_op<Type> > >(v0,v));
+                           default : break;
+                        }
+                     }
+                  }
+               }
+
+               switch (operation)
+               {
+                  #define case_stmt(op0,op1)                                                       \
+                  case op0 : return expr_gen.node_allocator_->                                     \
+                                template allocate_cr<typename details::bov_node<Type,op1<Type> > > \
+                                   (branch[0], v);                                                 \
+
+                  basic_opr_switch_statements
+                  extended_opr_switch_statements
+                  #undef case_stmt
+                  default : return error_node();
+               }
+            }
+         };
+
+         struct synthesize_cob_expression
+         {
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               const Type c = static_cast<details::literal_node<Type>*>(branch[0])->value();
+
+               free_node(*expr_gen.node_allocator_,branch[0]);
+
+               if (std::equal_to<T>()(T(0),c) && (details::e_mul == operation))
+               {
+                  free_node(*expr_gen.node_allocator_,branch[1]);
+
+                  return expr_gen(T(0));
+               }
+               else if (std::equal_to<T>()(T(0),c) && (details::e_div == operation))
+               {
+                  free_node(*expr_gen.node_allocator_, branch[1]);
+
+                  return expr_gen(T(0));
+               }
+               else if (std::equal_to<T>()(T(0),c) && (details::e_add == operation))
+                  return branch[1];
+               else if (std::equal_to<T>()(T(1),c) && (details::e_mul == operation))
+                  return branch[1];
+
+               if (details::is_cob_node(branch[1]))
+               {
+                  // Simplify expressions of the form:
+                  // 1. (1 * (2 * (3 * (4 * (5 * (6 * (7 * (8 * (9 + x))))))))) --> 40320 * (9 + x)
+                  // 2. (1 + (2 + (3 + (4 + (5 + (6 + (7 + (8 + (9 + x))))))))) --> 45 + x
+                  if (
+                       (operation == details::e_mul) ||
+                       (operation == details::e_add)
+                     )
+                  {
+                     details::cob_base_node<Type>* cobnode = static_cast<details::cob_base_node<Type>*>(branch[1]);
+
+                     if (operation == cobnode->operation())
+                     {
+                        switch (operation)
+                        {
+                           case details::e_add : cobnode->set_c(c + cobnode->c()); break;
+                           case details::e_mul : cobnode->set_c(c * cobnode->c()); break;
+                           default             : return error_node();
+                        }
+
+                        return cobnode;
+                     }
+                  }
+
+                  if (operation == details::e_mul)
+                  {
+                     details::cob_base_node<Type>* cobnode = static_cast<details::cob_base_node<Type>*>(branch[1]);
+                     details::operator_type cob_opr = cobnode->operation();
+
+                     if (
+                          (details::e_div == cob_opr) ||
+                          (details::e_mul == cob_opr)
+                        )
+                     {
+                        switch (cob_opr)
+                        {
+                           case details::e_div : cobnode->set_c(c * cobnode->c()); break;
+                           case details::e_mul : cobnode->set_c(cobnode->c() / c); break;
+                           default             : return error_node();
+                        }
+
+                        return cobnode;
+                     }
+                  }
+                  else if (operation == details::e_div)
+                  {
+                     details::cob_base_node<Type>* cobnode = static_cast<details::cob_base_node<Type>*>(branch[1]);
+                     details::operator_type cob_opr = cobnode->operation();
+
+                     if (
+                          (details::e_div == cob_opr) ||
+                          (details::e_mul == cob_opr)
+                        )
+                     {
+                        details::expression_node<Type>* new_cobnode = error_node();
+
+                        switch (cob_opr)
+                        {
+                           case details::e_div : new_cobnode = expr_gen.node_allocator_->
+                                                    template allocate_tt<typename details::cob_node<Type,details::mul_op<Type> > >
+                                                       (c / cobnode->c(), cobnode->move_branch(0));
+                                                 break;
+
+                           case details::e_mul : new_cobnode = expr_gen.node_allocator_->
+                                                    template allocate_tt<typename details::cob_node<Type,details::div_op<Type> > >
+                                                       (c / cobnode->c(), cobnode->move_branch(0));
+                                                 break;
+
+                           default             : return error_node();
+                        }
+
+                        free_node(*expr_gen.node_allocator_,branch[1]);
+
+                        return new_cobnode;
+                     }
+                  }
+               }
+               #ifndef exprtk_disable_enhanced_features
+               else if (details::is_sf3ext_node(branch[1]))
+               {
+                  expression_node_ptr result = error_node();
+
+                  const bool synthesis_result =
+                     synthesize_sf4ext_expression::template compile_right<ctype>
+                        (expr_gen, c, operation, branch[1], result);
+
+                  if (synthesis_result)
+                  {
+                     free_node(*expr_gen.node_allocator_,branch[1]);
+
+                     return result;
+                  }
+               }
+               #endif
+
+               switch (operation)
+               {
+                  #define case_stmt(op0,op1)                                                       \
+                  case op0 : return expr_gen.node_allocator_->                                     \
+                                template allocate_tt<typename details::cob_node<Type,op1<Type> > > \
+                                   (c,  branch[1]);                                                \
+
+                  basic_opr_switch_statements
+                  extended_opr_switch_statements
+                  #undef case_stmt
+                  default : return error_node();
+               }
+            }
+         };
+
+         struct synthesize_boc_expression
+         {
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               const Type c = static_cast<details::literal_node<Type>*>(branch[1])->value();
+
+               details::free_node(*(expr_gen.node_allocator_), branch[1]);
+
+               if (std::equal_to<T>()(T(0),c) && (details::e_mul == operation))
+               {
+                  free_node(*expr_gen.node_allocator_, branch[0]);
+
+                  return expr_gen(T(0));
+               }
+               else if (std::equal_to<T>()(T(0),c) && (details::e_div == operation))
+               {
+                  free_node(*expr_gen.node_allocator_, branch[0]);
+
+                  return expr_gen(std::numeric_limits<T>::quiet_NaN());
+               }
+               else if (std::equal_to<T>()(T(0),c) && (details::e_add == operation))
+                  return branch[0];
+               else if (std::equal_to<T>()(T(1),c) && (details::e_mul == operation))
+                  return branch[0];
+
+               if (details::is_boc_node(branch[0]))
+               {
+                  // Simplify expressions of the form:
+                  // 1. (((((((((x + 9) * 8) * 7) * 6) * 5) * 4) * 3) * 2) * 1) --> (x + 9) * 40320
+                  // 2. (((((((((x + 9) + 8) + 7) + 6) + 5) + 4) + 3) + 2) + 1) --> x + 45
+                  if (
+                       (operation == details::e_mul) ||
+                       (operation == details::e_add)
+                     )
+                  {
+                     details::boc_base_node<Type>* bocnode = static_cast<details::boc_base_node<Type>*>(branch[0]);
+
+                     if (operation == bocnode->operation())
+                     {
+                        switch (operation)
+                        {
+                           case details::e_add : bocnode->set_c(c + bocnode->c()); break;
+                           case details::e_mul : bocnode->set_c(c * bocnode->c()); break;
+                           default             : return error_node();
+                        }
+
+                        return bocnode;
+                     }
+                  }
+                  else if (operation == details::e_div)
+                  {
+                     details::boc_base_node<Type>* bocnode = static_cast<details::boc_base_node<Type>*>(branch[0]);
+                     details::operator_type        boc_opr = bocnode->operation();
+
+                     if (
+                          (details::e_div == boc_opr) ||
+                          (details::e_mul == boc_opr)
+                        )
+                     {
+                        switch (boc_opr)
+                        {
+                           case details::e_div : bocnode->set_c(c * bocnode->c()); break;
+                           case details::e_mul : bocnode->set_c(bocnode->c() / c); break;
+                           default             : return error_node();
+                        }
+
+                        return bocnode;
+                     }
+                  }
+                  else if (operation == details::e_pow)
+                  {
+                     // (v ^ c0) ^ c1 --> v ^(c0 * c1)
+                     details::boc_base_node<Type>* bocnode = static_cast<details::boc_base_node<Type>*>(branch[0]);
+                     details::operator_type        boc_opr = bocnode->operation();
+
+                     if (details::e_pow == boc_opr)
+                     {
+                        bocnode->set_c(bocnode->c() * c);
+
+                        return bocnode;
+                     }
+                  }
+               }
+
+               #ifndef exprtk_disable_enhanced_features
+               if (details::is_sf3ext_node(branch[0]))
+               {
+                  expression_node_ptr result = error_node();
+
+                  const bool synthesis_result =
+                     synthesize_sf4ext_expression::template compile_left<ctype>
+                        (expr_gen, c, operation, branch[0], result);
+
+                  if (synthesis_result)
+                  {
+                     free_node(*expr_gen.node_allocator_, branch[0]);
+
+                     return result;
+                  }
+               }
+               #endif
+
+               switch (operation)
+               {
+                  #define case_stmt(op0,op1)                                                       \
+                  case op0 : return expr_gen.node_allocator_->                                     \
+                                template allocate_cr<typename details::boc_node<Type,op1<Type> > > \
+                                   (branch[0], c);                                                 \
+
+                  basic_opr_switch_statements
+                  extended_opr_switch_statements
+                  #undef case_stmt
+                  default : return error_node();
+               }
+            }
+         };
+
+         struct synthesize_cocob_expression
+         {
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               expression_node_ptr result = error_node();
+
+               // (cob) o c --> cob
+               if (details::is_cob_node(branch[0]))
+               {
+                  details::cob_base_node<Type>* cobnode = static_cast<details::cob_base_node<Type>*>(branch[0]);
+
+                  const Type c = static_cast<details::literal_node<Type>*>(branch[1])->value();
+
+                  if (std::equal_to<T>()(T(0),c) && (details::e_mul == operation))
+                  {
+                     free_node(*expr_gen.node_allocator_, branch[0]);
+                     free_node(*expr_gen.node_allocator_, branch[1]);
+
+                     return expr_gen(T(0));
+                  }
+                  else if (std::equal_to<T>()(T(0),c) && (details::e_div == operation))
+                  {
+                     free_node(*expr_gen.node_allocator_, branch[0]);
+                     free_node(*expr_gen.node_allocator_, branch[1]);
+
+                     return expr_gen(T(std::numeric_limits<T>::quiet_NaN()));
+                  }
+                  else if (std::equal_to<T>()(T(0),c) && (details::e_add == operation))
+                  {
+                     free_node(*expr_gen.node_allocator_, branch[1]);
+
+                     return branch[0];
+                  }
+                  else if (std::equal_to<T>()(T(1),c) && (details::e_mul == operation))
+                  {
+                     free_node(*expr_gen.node_allocator_, branch[1]);
+
+                     return branch[0];
+                  }
+                  else if (std::equal_to<T>()(T(1),c) && (details::e_div == operation))
+                  {
+                     free_node(*expr_gen.node_allocator_, branch[1]);
+
+                     return branch[0];
+                  }
+
+                  const bool op_addsub = (details::e_add == cobnode->operation()) ||
+                                         (details::e_sub == cobnode->operation()) ;
+
+                  if (op_addsub)
+                  {
+                     switch (operation)
+                     {
+                        case details::e_add : cobnode->set_c(cobnode->c() + c); break;
+                        case details::e_sub : cobnode->set_c(cobnode->c() - c); break;
+                        default             : return error_node();
+                     }
+
+                     result = cobnode;
+                  }
+                  else if (details::e_mul == cobnode->operation())
+                  {
+                     switch (operation)
+                     {
+                        case details::e_mul : cobnode->set_c(cobnode->c() * c); break;
+                        case details::e_div : cobnode->set_c(cobnode->c() / c); break;
+                        default             : return error_node();
+                     }
+
+                     result = cobnode;
+                  }
+                  else if (details::e_div == cobnode->operation())
+                  {
+                     if (details::e_mul == operation)
+                     {
+                        cobnode->set_c(cobnode->c() * c);
+                        result = cobnode;
+                     }
+                     else if (details::e_div == operation)
+                     {
+                        result = expr_gen.node_allocator_->
+                                    template allocate_tt<typename details::cob_node<Type,details::div_op<Type> > >
+                                       (cobnode->c() / c, cobnode->move_branch(0));
+
+                        free_node(*expr_gen.node_allocator_, branch[0]);
+                     }
+                  }
+
+                  if (result)
+                  {
+                     free_node(*expr_gen.node_allocator_,branch[1]);
+                  }
+               }
+
+               // c o (cob) --> cob
+               else if (details::is_cob_node(branch[1]))
+               {
+                  details::cob_base_node<Type>* cobnode = static_cast<details::cob_base_node<Type>*>(branch[1]);
+
+                  const Type c = static_cast<details::literal_node<Type>*>(branch[0])->value();
+
+                  if (std::equal_to<T>()(T(0),c) && (details::e_mul == operation))
+                  {
+                     free_node(*expr_gen.node_allocator_, branch[0]);
+                     free_node(*expr_gen.node_allocator_, branch[1]);
+
+                     return expr_gen(T(0));
+                  }
+                  else if (std::equal_to<T>()(T(0),c) && (details::e_div == operation))
+                  {
+                     free_node(*expr_gen.node_allocator_, branch[0]);
+                     free_node(*expr_gen.node_allocator_, branch[1]);
+
+                     return expr_gen(T(0));
+                  }
+                  else if (std::equal_to<T>()(T(0),c) && (details::e_add == operation))
+                  {
+                     free_node(*expr_gen.node_allocator_, branch[0]);
+
+                     return branch[1];
+                  }
+                  else if (std::equal_to<T>()(T(1),c) && (details::e_mul == operation))
+                  {
+                     free_node(*expr_gen.node_allocator_, branch[0]);
+
+                     return branch[1];
+                  }
+
+                  if (details::e_add == cobnode->operation())
+                  {
+                     if (details::e_add == operation)
+                     {
+                        cobnode->set_c(c + cobnode->c());
+                        result = cobnode;
+                     }
+                     else if (details::e_sub == operation)
+                     {
+                        result = expr_gen.node_allocator_->
+                                    template allocate_tt<typename details::cob_node<Type,details::sub_op<Type> > >
+                                       (c - cobnode->c(), cobnode->move_branch(0));
+
+                        free_node(*expr_gen.node_allocator_,branch[1]);
+                     }
+                  }
+                  else if (details::e_sub == cobnode->operation())
+                  {
+                     if (details::e_add == operation)
+                     {
+                        cobnode->set_c(c + cobnode->c());
+                        result = cobnode;
+                     }
+                     else if (details::e_sub == operation)
+                     {
+                        result = expr_gen.node_allocator_->
+                                    template allocate_tt<typename details::cob_node<Type,details::add_op<Type> > >
+                                       (c - cobnode->c(), cobnode->move_branch(0));
+
+                        free_node(*expr_gen.node_allocator_,branch[1]);
+                     }
+                  }
+                  else if (details::e_mul == cobnode->operation())
+                  {
+                     if (details::e_mul == operation)
+                     {
+                        cobnode->set_c(c * cobnode->c());
+                        result = cobnode;
+                     }
+                     else if (details::e_div == operation)
+                     {
+                        result = expr_gen.node_allocator_->
+                                    template allocate_tt<typename details::cob_node<Type,details::div_op<Type> > >
+                                       (c / cobnode->c(), cobnode->move_branch(0));
+
+                        free_node(*expr_gen.node_allocator_,branch[1]);
+                     }
+                  }
+                  else if (details::e_div == cobnode->operation())
+                  {
+                     if (details::e_mul == operation)
+                     {
+                        cobnode->set_c(c * cobnode->c());
+                        result = cobnode;
+                     }
+                     else if (details::e_div == operation)
+                     {
+                        result = expr_gen.node_allocator_->
+                                    template allocate_tt<typename details::cob_node<Type,details::mul_op<Type> > >
+                                       (c / cobnode->c(), cobnode->move_branch(0));
+
+                        free_node(*expr_gen.node_allocator_,branch[1]);
+                     }
+                  }
+
+                  if (result)
+                  {
+                     free_node(*expr_gen.node_allocator_,branch[0]);
+                  }
+               }
+
+               return result;
+            }
+         };
+
+         struct synthesize_coboc_expression
+         {
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               expression_node_ptr result = error_node();
+
+               // (boc) o c --> boc
+               if (details::is_boc_node(branch[0]))
+               {
+                  details::boc_base_node<Type>* bocnode = static_cast<details::boc_base_node<Type>*>(branch[0]);
+
+                  const Type c = static_cast<details::literal_node<Type>*>(branch[1])->value();
+
+                  if (details::e_add == bocnode->operation())
+                  {
+                     switch (operation)
+                     {
+                        case details::e_add : bocnode->set_c(bocnode->c() + c); break;
+                        case details::e_sub : bocnode->set_c(bocnode->c() - c); break;
+                        default             : return error_node();
+                     }
+
+                     result = bocnode;
+                  }
+                  else if (details::e_mul == bocnode->operation())
+                  {
+                     switch (operation)
+                     {
+                        case details::e_mul : bocnode->set_c(bocnode->c() * c); break;
+                        case details::e_div : bocnode->set_c(bocnode->c() / c); break;
+                        default             : return error_node();
+                     }
+
+                     result = bocnode;
+                  }
+                  else if (details::e_sub == bocnode->operation())
+                  {
+                     if (details::e_add == operation)
+                     {
+                        result = expr_gen.node_allocator_->
+                                    template allocate_tt<typename details::boc_node<Type,details::add_op<Type> > >
+                                       (bocnode->move_branch(0), c - bocnode->c());
+
+                        free_node(*expr_gen.node_allocator_,branch[0]);
+                     }
+                     else if (details::e_sub == operation)
+                     {
+                        bocnode->set_c(bocnode->c() + c);
+                        result = bocnode;
+                     }
+                  }
+                  else if (details::e_div == bocnode->operation())
+                  {
+                     switch (operation)
+                     {
+                        case details::e_div : bocnode->set_c(bocnode->c() * c); break;
+                        case details::e_mul : bocnode->set_c(bocnode->c() / c); break;
+                        default             : return error_node();
+                     }
+
+                     result = bocnode;
+                  }
+
+                  if (result)
+                  {
+                     free_node(*expr_gen.node_allocator_, branch[1]);
+                  }
+               }
+
+               // c o (boc) --> boc
+               else if (details::is_boc_node(branch[1]))
+               {
+                  details::boc_base_node<Type>* bocnode = static_cast<details::boc_base_node<Type>*>(branch[1]);
+
+                  const Type c = static_cast<details::literal_node<Type>*>(branch[0])->value();
+
+                  if (details::e_add == bocnode->operation())
+                  {
+                     if (details::e_add == operation)
+                     {
+                        bocnode->set_c(c + bocnode->c());
+                        result = bocnode;
+                     }
+                     else if (details::e_sub == operation)
+                     {
+                        result = expr_gen.node_allocator_->
+                                    template allocate_tt<typename details::cob_node<Type,details::sub_op<Type> > >
+                                       (c - bocnode->c(), bocnode->move_branch(0));
+
+                        free_node(*expr_gen.node_allocator_,branch[1]);
+                     }
+                  }
+                  else if (details::e_sub == bocnode->operation())
+                  {
+                     if (details::e_add == operation)
+                     {
+                        result = expr_gen.node_allocator_->
+                                    template allocate_tt<typename details::boc_node<Type,details::add_op<Type> > >
+                                       (bocnode->move_branch(0), c - bocnode->c());
+
+                        free_node(*expr_gen.node_allocator_,branch[1]);
+                     }
+                     else if (details::e_sub == operation)
+                     {
+                        result = expr_gen.node_allocator_->
+                                    template allocate_tt<typename details::cob_node<Type,details::sub_op<Type> > >
+                                       (c + bocnode->c(), bocnode->move_branch(0));
+
+                        free_node(*expr_gen.node_allocator_,branch[1]);
+                     }
+                  }
+                  else if (details::e_mul == bocnode->operation())
+                  {
+                     if (details::e_mul == operation)
+                     {
+                        bocnode->set_c(c * bocnode->c());
+                        result = bocnode;
+                     }
+                     else if (details::e_div == operation)
+                     {
+                        result = expr_gen.node_allocator_->
+                                    template allocate_tt<typename details::cob_node<Type,details::div_op<Type> > >
+                                       (c / bocnode->c(), bocnode->move_branch(0));
+
+                        free_node(*expr_gen.node_allocator_,branch[1]);
+                     }
+                  }
+                  else if (details::e_div == bocnode->operation())
+                  {
+                     if (details::e_mul == operation)
+                     {
+                        bocnode->set_c(bocnode->c() / c);
+                        result = bocnode;
+                     }
+                     else if (details::e_div == operation)
+                     {
+                        result = expr_gen.node_allocator_->
+                                    template allocate_tt<typename details::cob_node<Type,details::div_op<Type> > >
+                                       (c * bocnode->c(), bocnode->move_branch(0));
+
+                        free_node(*expr_gen.node_allocator_,branch[1]);
+                     }
+                  }
+
+                  if (result)
+                  {
+                     free_node(*expr_gen.node_allocator_,branch[0]);
+                  }
+               }
+
+               return result;
+            }
+         };
+
+         #ifndef exprtk_disable_enhanced_features
+         inline bool synthesize_expression(const details::operator_type& operation,
+                                           expression_node_ptr (&branch)[2],
+                                           expression_node_ptr& result)
+         {
+            result = error_node();
+
+            if (!operation_optimisable(operation))
+               return false;
+
+            const std::string node_id = branch_to_id(branch);
+
+            const typename synthesize_map_t::iterator itr = synthesize_map_.find(node_id);
+
+            if (synthesize_map_.end() != itr)
+            {
+               result = itr->second((*this), operation, branch);
+
+               return true;
+            }
+            else
+               return false;
+         }
+
+         struct synthesize_vov_expression
+         {
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               const Type& v1 = static_cast<details::variable_node<Type>*>(branch[0])->ref();
+               const Type& v2 = static_cast<details::variable_node<Type>*>(branch[1])->ref();
+
+               switch (operation)
+               {
+                  #define case_stmt(op0,op1)                                                       \
+                  case op0 : return expr_gen.node_allocator_->                                     \
+                                template allocate_rr<typename details::vov_node<Type,op1<Type> > > \
+                                   (v1, v2);                                                       \
+
+                  basic_opr_switch_statements
+                  extended_opr_switch_statements
+                  #undef case_stmt
+                  default : return error_node();
+               }
+            }
+         };
+
+         struct synthesize_cov_expression
+         {
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               const Type  c = static_cast<details::literal_node<Type>*> (branch[0])->value();
+               const Type& v = static_cast<details::variable_node<Type>*>(branch[1])->ref  ();
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+
+               if (std::equal_to<T>()(T(0),c) && (details::e_mul == operation))
+                  return expr_gen(T(0));
+               else if (std::equal_to<T>()(T(0),c) && (details::e_div == operation))
+                  return expr_gen(T(0));
+               else if (std::equal_to<T>()(T(0),c) && (details::e_add == operation))
+                  return static_cast<details::variable_node<Type>*>(branch[1]);
+               else if (std::equal_to<T>()(T(1),c) && (details::e_mul == operation))
+                  return static_cast<details::variable_node<Type>*>(branch[1]);
+
+               switch (operation)
+               {
+                  #define case_stmt(op0,op1)                                                       \
+                  case op0 : return expr_gen.node_allocator_->                                     \
+                                template allocate_cr<typename details::cov_node<Type,op1<Type> > > \
+                                   (c, v);                                                         \
+
+                  basic_opr_switch_statements
+                  extended_opr_switch_statements
+                  #undef case_stmt
+                  default : return error_node();
+               }
+            }
+         };
+
+         struct synthesize_voc_expression
+         {
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               const Type& v = static_cast<details::variable_node<Type>*>(branch[0])->ref  ();
+               const Type  c = static_cast<details::literal_node<Type>*> (branch[1])->value();
+
+               details::free_node(*(expr_gen.node_allocator_), branch[1]);
+
+               if (expr_gen.cardinal_pow_optimisable(operation,c))
+               {
+                  if (std::equal_to<T>()(T(1),c))
+                     return branch[0];
+                  else
+                     return expr_gen.cardinal_pow_optimisation(v,c);
+               }
+               else if (std::equal_to<T>()(T(0),c) && (details::e_mul == operation))
+                  return expr_gen(T(0));
+               else if (std::equal_to<T>()(T(0),c) && (details::e_div == operation))
+                  return expr_gen(std::numeric_limits<T>::quiet_NaN());
+               else if (std::equal_to<T>()(T(0),c) && (details::e_add == operation))
+                  return static_cast<details::variable_node<Type>*>(branch[0]);
+               else if (std::equal_to<T>()(T(1),c) && (details::e_mul == operation))
+                  return static_cast<details::variable_node<Type>*>(branch[0]);
+               else if (std::equal_to<T>()(T(1),c) && (details::e_div == operation))
+                  return static_cast<details::variable_node<Type>*>(branch[0]);
+
+               switch (operation)
+               {
+                  #define case_stmt(op0,op1)                                                       \
+                  case op0 : return expr_gen.node_allocator_->                                     \
+                                template allocate_rc<typename details::voc_node<Type,op1<Type> > > \
+                                   (v, c);                                                         \
+
+                  basic_opr_switch_statements
+                  extended_opr_switch_statements
+                  #undef case_stmt
+                  default : return error_node();
+               }
+            }
+         };
+
+         struct synthesize_sf3ext_expression
+         {
+            template <typename T0, typename T1, typename T2>
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& sf3opr,
+                                                      T0 t0, T1 t1, T2 t2)
+            {
+               switch (sf3opr)
+               {
+                  #define case_stmt(op)                                                                              \
+                  case details::e_sf##op : return details::T0oT1oT2_sf3ext<T,T0,T1,T2,details::sf##op##_op<Type> >:: \
+                                allocate(*(expr_gen.node_allocator_), t0, t1, t2);                                   \
+
+                  case_stmt(00) case_stmt(01) case_stmt(02) case_stmt(03)
+                  case_stmt(04) case_stmt(05) case_stmt(06) case_stmt(07)
+                  case_stmt(08) case_stmt(09) case_stmt(10) case_stmt(11)
+                  case_stmt(12) case_stmt(13) case_stmt(14) case_stmt(15)
+                  case_stmt(16) case_stmt(17) case_stmt(18) case_stmt(19)
+                  case_stmt(20) case_stmt(21) case_stmt(22) case_stmt(23)
+                  case_stmt(24) case_stmt(25) case_stmt(26) case_stmt(27)
+                  case_stmt(28) case_stmt(29) case_stmt(30)
+                  #undef case_stmt
+                  default : return error_node();
+               }
+            }
+
+            template <typename T0, typename T1, typename T2>
+            static inline bool compile(expression_generator<Type>& expr_gen, const std::string& id,
+                                       T0 t0, T1 t1, T2 t2,
+                                       expression_node_ptr& result)
+            {
+               details::operator_type sf3opr;
+
+               if (!expr_gen.sf3_optimisable(id,sf3opr))
+                  return false;
+               else
+                  result = synthesize_sf3ext_expression::template process<T0, T1, T2>
+                              (expr_gen, sf3opr, t0, t1, t2);
+
+               return true;
+            }
+         };
+
+         struct synthesize_sf4ext_expression
+         {
+            template <typename T0, typename T1, typename T2, typename T3>
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& sf4opr,
+                                                      T0 t0, T1 t1, T2 t2, T3 t3)
+            {
+               switch (sf4opr)
+               {
+                  #define case_stmt0(op)                                                                                      \
+                  case details::e_sf##op : return details::T0oT1oT2oT3_sf4ext<Type,T0,T1,T2,T3,details::sf##op##_op<Type> >:: \
+                                allocate(*(expr_gen.node_allocator_), t0, t1, t2, t3);                                        \
+
+
+                  #define case_stmt1(op)                                                                                             \
+                  case details::e_sf4ext##op : return details::T0oT1oT2oT3_sf4ext<Type,T0,T1,T2,T3,details::sfext##op##_op<Type> >:: \
+                                allocate(*(expr_gen.node_allocator_), t0, t1, t2, t3);                                               \
+
+                  case_stmt0(48) case_stmt0(49) case_stmt0(50) case_stmt0(51)
+                  case_stmt0(52) case_stmt0(53) case_stmt0(54) case_stmt0(55)
+                  case_stmt0(56) case_stmt0(57) case_stmt0(58) case_stmt0(59)
+                  case_stmt0(60) case_stmt0(61) case_stmt0(62) case_stmt0(63)
+                  case_stmt0(64) case_stmt0(65) case_stmt0(66) case_stmt0(67)
+                  case_stmt0(68) case_stmt0(69) case_stmt0(70) case_stmt0(71)
+                  case_stmt0(72) case_stmt0(73) case_stmt0(74) case_stmt0(75)
+                  case_stmt0(76) case_stmt0(77) case_stmt0(78) case_stmt0(79)
+                  case_stmt0(80) case_stmt0(81) case_stmt0(82) case_stmt0(83)
+
+                  case_stmt1(00) case_stmt1(01) case_stmt1(02) case_stmt1(03)
+                  case_stmt1(04) case_stmt1(05) case_stmt1(06) case_stmt1(07)
+                  case_stmt1(08) case_stmt1(09) case_stmt1(10) case_stmt1(11)
+                  case_stmt1(12) case_stmt1(13) case_stmt1(14) case_stmt1(15)
+                  case_stmt1(16) case_stmt1(17) case_stmt1(18) case_stmt1(19)
+                  case_stmt1(20) case_stmt1(21) case_stmt1(22) case_stmt1(23)
+                  case_stmt1(24) case_stmt1(25) case_stmt1(26) case_stmt1(27)
+                  case_stmt1(28) case_stmt1(29) case_stmt1(30) case_stmt1(31)
+                  case_stmt1(32) case_stmt1(33) case_stmt1(34) case_stmt1(35)
+                  case_stmt1(36) case_stmt1(37) case_stmt1(38) case_stmt1(39)
+                  case_stmt1(40) case_stmt1(41) case_stmt1(42) case_stmt1(43)
+                  case_stmt1(44) case_stmt1(45) case_stmt1(46) case_stmt1(47)
+                  case_stmt1(48) case_stmt1(49) case_stmt1(50) case_stmt1(51)
+                  case_stmt1(52) case_stmt1(53) case_stmt1(54) case_stmt1(55)
+                  case_stmt1(56) case_stmt1(57) case_stmt1(58) case_stmt1(59)
+                  case_stmt1(60) case_stmt1(61)
+
+                  #undef case_stmt0
+                  #undef case_stmt1
+                  default : return error_node();
+               }
+            }
+
+            template <typename T0, typename T1, typename T2, typename T3>
+            static inline bool compile(expression_generator<Type>& expr_gen, const std::string& id,
+                                       T0 t0, T1 t1, T2 t2, T3 t3,
+                                       expression_node_ptr& result)
+            {
+               details::operator_type sf4opr;
+
+               if (!expr_gen.sf4_optimisable(id,sf4opr))
+                  return false;
+               else
+                  result = synthesize_sf4ext_expression::template process<T0, T1, T2, T3>
+                              (expr_gen, sf4opr, t0, t1, t2, t3);
+
+               return true;
+            }
+
+            // T o (sf3ext)
+            template <typename ExternalType>
+            static inline bool compile_right(expression_generator<Type>& expr_gen,
+                                             ExternalType t,
+                                             const details::operator_type& operation,
+                                             expression_node_ptr& sf3node,
+                                             expression_node_ptr& result)
+            {
+               if (!details::is_sf3ext_node(sf3node))
+                  return false;
+
+               typedef details::T0oT1oT2_base_node<Type>* sf3ext_base_ptr;
+
+               sf3ext_base_ptr n = static_cast<sf3ext_base_ptr>(sf3node);
+               const std::string id = "t" + expr_gen.to_str(operation) + "(" + n->type_id() + ")";
+
+               switch (n->type())
+               {
+                  case details::expression_node<Type>::e_covoc : return compile_right_impl
+                                                                    <typename covoc_t::sf3_type_node,ExternalType, ctype, vtype, ctype>
+                                                                       (expr_gen, id, t, sf3node, result);
+
+                  case details::expression_node<Type>::e_covov : return compile_right_impl
+                                                                    <typename covov_t::sf3_type_node,ExternalType, ctype, vtype, vtype>
+                                                                       (expr_gen, id, t, sf3node, result);
+
+                  case details::expression_node<Type>::e_vocov : return compile_right_impl
+                                                                    <typename vocov_t::sf3_type_node,ExternalType, vtype, ctype, vtype>
+                                                                       (expr_gen, id, t, sf3node, result);
+
+                  case details::expression_node<Type>::e_vovoc : return compile_right_impl
+                                                                    <typename vovoc_t::sf3_type_node,ExternalType, vtype, vtype, ctype>
+                                                                       (expr_gen, id, t, sf3node, result);
+
+                  case details::expression_node<Type>::e_vovov : return compile_right_impl
+                                                                    <typename vovov_t::sf3_type_node,ExternalType, vtype, vtype, vtype>
+                                                                       (expr_gen, id, t, sf3node, result);
+
+                  default                                      : return false;
+               }
+            }
+
+            // (sf3ext) o T
+            template <typename ExternalType>
+            static inline bool compile_left(expression_generator<Type>& expr_gen,
+                                            ExternalType t,
+                                            const details::operator_type& operation,
+                                            expression_node_ptr& sf3node,
+                                            expression_node_ptr& result)
+            {
+               if (!details::is_sf3ext_node(sf3node))
+                  return false;
+
+               typedef details::T0oT1oT2_base_node<Type>* sf3ext_base_ptr;
+
+               sf3ext_base_ptr n = static_cast<sf3ext_base_ptr>(sf3node);
+
+               const std::string id = "(" + n->type_id() + ")" + expr_gen.to_str(operation) + "t";
+
+               switch (n->type())
+               {
+                  case details::expression_node<Type>::e_covoc : return compile_left_impl
+                                                                    <typename covoc_t::sf3_type_node,ExternalType, ctype, vtype, ctype>
+                                                                       (expr_gen, id, t, sf3node, result);
+
+                  case details::expression_node<Type>::e_covov : return compile_left_impl
+                                                                    <typename covov_t::sf3_type_node,ExternalType, ctype, vtype, vtype>
+                                                                       (expr_gen, id, t, sf3node, result);
+
+                  case details::expression_node<Type>::e_vocov : return compile_left_impl
+                                                                    <typename vocov_t::sf3_type_node,ExternalType, vtype, ctype, vtype>
+                                                                       (expr_gen, id, t, sf3node, result);
+
+                  case details::expression_node<Type>::e_vovoc : return compile_left_impl
+                                                                    <typename vovoc_t::sf3_type_node,ExternalType, vtype, vtype, ctype>
+                                                                       (expr_gen, id, t, sf3node, result);
+
+                  case details::expression_node<Type>::e_vovov : return compile_left_impl
+                                                                    <typename vovov_t::sf3_type_node,ExternalType, vtype, vtype, vtype>
+                                                                       (expr_gen, id, t, sf3node, result);
+
+                  default                                      : return false;
+               }
+            }
+
+            template <typename SF3TypeNode, typename ExternalType, typename T0, typename T1, typename T2>
+            static inline bool compile_right_impl(expression_generator<Type>& expr_gen,
+                                                  const std::string& id,
+                                                  ExternalType t,
+                                                  expression_node_ptr& node,
+                                                  expression_node_ptr& result)
+            {
+               SF3TypeNode* n = dynamic_cast<SF3TypeNode*>(node);
+
+               if (n)
+               {
+                  T0 t0 = n->t0();
+                  T1 t1 = n->t1();
+                  T2 t2 = n->t2();
+
+                  return synthesize_sf4ext_expression::template compile<ExternalType, T0, T1, T2>
+                            (expr_gen, id, t, t0, t1, t2, result);
+               }
+               else
+                  return false;
+            }
+
+            template <typename SF3TypeNode, typename ExternalType, typename T0, typename T1, typename T2>
+            static inline bool compile_left_impl(expression_generator<Type>& expr_gen,
+                                                 const std::string& id,
+                                                 ExternalType t,
+                                                 expression_node_ptr& node,
+                                                 expression_node_ptr& result)
+            {
+               SF3TypeNode* n = dynamic_cast<SF3TypeNode*>(node);
+
+               if (n)
+               {
+                  T0 t0 = n->t0();
+                  T1 t1 = n->t1();
+                  T2 t2 = n->t2();
+
+                  return synthesize_sf4ext_expression::template compile<T0, T1, T2, ExternalType>
+                            (expr_gen, id, t0, t1, t2, t, result);
+               }
+               else
+                  return false;
+            }
+         };
+
+         struct synthesize_vovov_expression0
+         {
+            typedef typename vovov_t::type0 node_type;
+            typedef typename vovov_t::sf3_type sf3_type;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // (v0 o0 v1) o1 (v2)
+               const details::vov_base_node<Type>* vov = static_cast<details::vov_base_node<Type>*>(branch[0]);
+               const Type& v0 = vov->v0();
+               const Type& v1 = vov->v1();
+               const Type& v2 = static_cast<details::variable_node<Type>*>(branch[1])->ref();
+               const details::operator_type o0 = vov->operation();
+               const details::operator_type o1 = operation;
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+
+               expression_node_ptr result = error_node();
+
+               if (expr_gen.parser_->settings_.strength_reduction_enabled())
+               {
+                  // (v0 / v1) / v2 --> (vovov) v0 / (v1 * v2)
+                  if ((details::e_div == o0) && (details::e_div == o1))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<vtype,vtype,vtype>(expr_gen, "t/(t*t)", v0, v1, v2, result);
+
+                     exprtk_debug(("(v0 / v1) / v2 --> (vovov) v0 / (v1 * v2)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+               }
+
+               const bool synthesis_result =
+                  synthesize_sf3ext_expression::template compile<vtype, vtype, vtype>
+                     (expr_gen, id(expr_gen, o0, o1), v0, v1, v2, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+               else if (!expr_gen.valid_operator(o1,f1))
+                  return error_node();
+               else
+                  return node_type::allocate(*(expr_gen.node_allocator_), v0, v1, v2, f0, f1);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0, const details::operator_type o1)
+            {
+               return details::build_string()
+                         << "(t" << expr_gen.to_str(o0)
+                         << "t)" << expr_gen.to_str(o1)
+                         << "t";
+            }
+         };
+
+         struct synthesize_vovov_expression1
+         {
+            typedef typename vovov_t::type1 node_type;
+            typedef typename vovov_t::sf3_type sf3_type;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // (v0) o0 (v1 o1 v2)
+               const details::vov_base_node<Type>* vov = static_cast<details::vov_base_node<Type>*>(branch[1]);
+               const Type& v0 = static_cast<details::variable_node<Type>*>(branch[0])->ref();
+               const Type& v1 = vov->v0();
+               const Type& v2 = vov->v1();
+               const details::operator_type o0 = operation;
+               const details::operator_type o1 = vov->operation();
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               if (expr_gen.parser_->settings_.strength_reduction_enabled())
+               {
+                  // v0 / (v1 / v2) --> (vovov) (v0 * v2) / v1
+                  if ((details::e_div == o0) && (details::e_div == o1))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<vtype,vtype,vtype>(expr_gen, "(t*t)/t", v0, v2, v1, result);
+
+                     exprtk_debug(("v0 / (v1 / v2) --> (vovov) (v0 * v2) / v1\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+               }
+
+               const bool synthesis_result =
+                  synthesize_sf3ext_expression::template compile<vtype, vtype, vtype>
+                     (expr_gen, id(expr_gen, o0, o1), v0, v1, v2, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+               else if (!expr_gen.valid_operator(o1,f1))
+                  return error_node();
+               else
+                  return node_type::allocate(*(expr_gen.node_allocator_), v0, v1, v2, f0, f1);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0, const details::operator_type o1)
+            {
+               return details::build_string()
+                         << "t"  << expr_gen.to_str(o0)
+                         << "(t" << expr_gen.to_str(o1)
+                         << "t)";
+            }
+         };
+
+         struct synthesize_vovoc_expression0
+         {
+            typedef typename vovoc_t::type0 node_type;
+            typedef typename vovoc_t::sf3_type sf3_type;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // (v0 o0 v1) o1 (c)
+               const details::vov_base_node<Type>* vov = static_cast<details::vov_base_node<Type>*>(branch[0]);
+               const Type& v0 = vov->v0();
+               const Type& v1 = vov->v1();
+               const Type   c = static_cast<details::literal_node<Type>*>(branch[1])->value();
+               const details::operator_type o0 = vov->operation();
+               const details::operator_type o1 = operation;
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               if (expr_gen.parser_->settings_.strength_reduction_enabled())
+               {
+                  // (v0 / v1) / c --> (vovoc) v0 / (v1 * c)
+                  if ((details::e_div == o0) && (details::e_div == o1))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<vtype,vtype,ctype>(expr_gen, "t/(t*t)", v0, v1, c, result);
+
+                     exprtk_debug(("(v0 / v1) / c --> (vovoc) v0 / (v1 * c)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+               }
+
+               const bool synthesis_result =
+                  synthesize_sf3ext_expression::template compile<vtype, vtype, ctype>
+                     (expr_gen, id(expr_gen, o0, o1), v0, v1, c, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+               else if (!expr_gen.valid_operator(o1,f1))
+                  return error_node();
+               else
+                  return node_type::allocate(*(expr_gen.node_allocator_), v0, v1, c, f0, f1);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0, const details::operator_type o1)
+            {
+               return details::build_string()
+                         << "(t" << expr_gen.to_str(o0)
+                         << "t)" << expr_gen.to_str(o1)
+                         << "t";
+            }
+         };
+
+         struct synthesize_vovoc_expression1
+         {
+            typedef typename vovoc_t::type1 node_type;
+            typedef typename vovoc_t::sf3_type sf3_type;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // (v0) o0 (v1 o1 c)
+               const details::voc_base_node<Type>* voc = static_cast<const details::voc_base_node<Type>*>(branch[1]);
+               const Type& v0 = static_cast<details::variable_node<Type>*>(branch[0])->ref();
+               const Type& v1 = voc->v();
+               const Type   c = voc->c();
+               const details::operator_type o0 = operation;
+               const details::operator_type o1 = voc->operation();
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               if (expr_gen.parser_->settings_.strength_reduction_enabled())
+               {
+                  // v0 / (v1 / c) --> (vocov) (v0 * c) / v1
+                  if ((details::e_div == o0) && (details::e_div == o1))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<vtype,ctype,vtype>(expr_gen, "(t*t)/t", v0, c, v1, result);
+
+                     exprtk_debug(("v0 / (v1 / c) --> (vocov) (v0 * c) / v1\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+               }
+
+               const bool synthesis_result =
+                  synthesize_sf3ext_expression::template compile<vtype, vtype, ctype>
+                     (expr_gen, id(expr_gen, o0, o1), v0, v1, c, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+               else if (!expr_gen.valid_operator(o1,f1))
+                  return error_node();
+               else
+                  return node_type::allocate(*(expr_gen.node_allocator_), v0, v1, c, f0, f1);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0, const details::operator_type o1)
+            {
+               return details::build_string()
+                         << "t"  << expr_gen.to_str(o0)
+                         << "(t" << expr_gen.to_str(o1)
+                         << "t)";
+            }
+         };
+
+         struct synthesize_vocov_expression0
+         {
+            typedef typename vocov_t::type0 node_type;
+            typedef typename vocov_t::sf3_type sf3_type;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // (v0 o0 c) o1 (v1)
+               const details::voc_base_node<Type>* voc = static_cast<details::voc_base_node<Type>*>(branch[0]);
+               const Type& v0 = voc->v();
+               const Type   c = voc->c();
+               const Type& v1 = static_cast<details::variable_node<Type>*>(branch[1])->ref();
+               const details::operator_type o0 = voc->operation();
+               const details::operator_type o1 = operation;
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+
+               expression_node_ptr result = error_node();
+
+               if (expr_gen.parser_->settings_.strength_reduction_enabled())
+               {
+                  // (v0 / c) / v1 --> (vovoc) v0 / (v1 * c)
+                  if ((details::e_div == o0) && (details::e_div == o1))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<vtype,vtype,ctype>(expr_gen, "t/(t*t)", v0, v1, c, result);
+
+                     exprtk_debug(("(v0 / c) / v1 --> (vovoc) v0 / (v1 * c)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+               }
+
+               const bool synthesis_result =
+                  synthesize_sf3ext_expression::template compile<vtype, ctype, vtype>
+                     (expr_gen, id(expr_gen, o0, o1), v0, c, v1, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+               else if (!expr_gen.valid_operator(o1,f1))
+                  return error_node();
+               else
+                  return node_type::allocate(*(expr_gen.node_allocator_), v0, c, v1, f0, f1);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0, const details::operator_type o1)
+            {
+               return details::build_string()
+                         << "(t" << expr_gen.to_str(o0)
+                         << "t)" << expr_gen.to_str(o1)
+                         << "t";
+            }
+         };
+
+         struct synthesize_vocov_expression1
+         {
+            typedef typename vocov_t::type1 node_type;
+            typedef typename vocov_t::sf3_type sf3_type;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // (v0) o0 (c o1 v1)
+               const details::cov_base_node<Type>* cov = static_cast<details::cov_base_node<Type>*>(branch[1]);
+               const Type& v0 = static_cast<details::variable_node<Type>*>(branch[0])->ref();
+               const Type   c = cov->c();
+               const Type& v1 = cov->v();
+               const details::operator_type o0 = operation;
+               const details::operator_type o1 = cov->operation();
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               if (expr_gen.parser_->settings_.strength_reduction_enabled())
+               {
+                  // v0 / (c / v1) --> (vovoc) (v0 * v1) / c
+                  if ((details::e_div == o0) && (details::e_div == o1))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<vtype, vtype, ctype>(expr_gen, "(t*t)/t", v0, v1, c, result);
+
+                     exprtk_debug(("v0 / (c / v1) --> (vovoc) (v0 * v1) / c\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+               }
+
+               const bool synthesis_result =
+                  synthesize_sf3ext_expression::template compile<vtype, ctype, vtype>
+                     (expr_gen, id(expr_gen, o0, o1), v0, c, v1, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+               else if (!expr_gen.valid_operator(o1,f1))
+                  return error_node();
+               else
+                  return node_type::allocate(*(expr_gen.node_allocator_), v0, c, v1, f0, f1);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0, const details::operator_type o1)
+            {
+               return details::build_string()
+                         << "t"  << expr_gen.to_str(o0)
+                         << "(t" << expr_gen.to_str(o1)
+                         << "t)";
+            }
+         };
+
+         struct synthesize_covov_expression0
+         {
+            typedef typename covov_t::type0 node_type;
+            typedef typename covov_t::sf3_type sf3_type;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // (c o0 v0) o1 (v1)
+               const details::cov_base_node<Type>* cov = static_cast<details::cov_base_node<Type>*>(branch[0]);
+               const Type   c = cov->c();
+               const Type& v0 = cov->v();
+               const Type& v1 = static_cast<details::variable_node<Type>*>(branch[1])->ref();
+               const details::operator_type o0 = cov->operation();
+               const details::operator_type o1 = operation;
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+
+               expression_node_ptr result = error_node();
+
+               if (expr_gen.parser_->settings_.strength_reduction_enabled())
+               {
+                  // (c / v0) / v1 --> (covov) c / (v0 * v1)
+                  if ((details::e_div == o0) && (details::e_div == o1))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype, vtype, vtype>(expr_gen, "t/(t*t)", c, v0, v1, result);
+
+                     exprtk_debug(("(c / v0) / v1 --> (covov) c / (v0 * v1)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+               }
+
+               const bool synthesis_result =
+                  synthesize_sf3ext_expression::template compile<ctype, vtype, vtype>
+                     (expr_gen, id(expr_gen, o0, o1), c, v0, v1, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+               else if (!expr_gen.valid_operator(o1,f1))
+                  return error_node();
+               else
+                  return node_type::allocate(*(expr_gen.node_allocator_), c, v0, v1, f0, f1);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0, const details::operator_type o1)
+            {
+               return details::build_string()
+                         << "(t" << expr_gen.to_str(o0)
+                         << "t)" << expr_gen.to_str(o1)
+                         << "t";
+            }
+         };
+
+         struct synthesize_covov_expression1
+         {
+            typedef typename covov_t::type1 node_type;
+            typedef typename covov_t::sf3_type sf3_type;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // (c) o0 (v0 o1 v1)
+               const details::vov_base_node<Type>* vov = static_cast<details::vov_base_node<Type>*>(branch[1]);
+               const Type   c = static_cast<details::literal_node<Type>*>(branch[0])->value();
+               const Type& v0 = vov->v0();
+               const Type& v1 = vov->v1();
+               const details::operator_type o0 = operation;
+               const details::operator_type o1 = vov->operation();
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               if (expr_gen.parser_->settings_.strength_reduction_enabled())
+               {
+                  // c / (v0 / v1) --> (covov) (c * v1) / v0
+                  if ((details::e_div == o0) && (details::e_div == o1))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype, vtype, vtype>(expr_gen, "(t*t)/t", c, v1, v0, result);
+
+                     exprtk_debug(("c / (v0 / v1) --> (covov) (c * v1) / v0\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+               }
+
+               const bool synthesis_result =
+                  synthesize_sf3ext_expression::template compile<ctype, vtype, vtype>
+                     (expr_gen, id(expr_gen, o0, o1), c, v0, v1, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+               else if (!expr_gen.valid_operator(o1,f1))
+                  return error_node();
+               else
+                  return node_type::allocate(*(expr_gen.node_allocator_), c, v0, v1, f0, f1);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen, const details::operator_type o0, const details::operator_type o1)
+            {
+               return details::build_string()
+                         << "t"  << expr_gen.to_str(o0)
+                         << "(t" << expr_gen.to_str(o1)
+                         << "t)";
+            }
+         };
+
+         struct synthesize_covoc_expression0
+         {
+            typedef typename covoc_t::type0 node_type;
+            typedef typename covoc_t::sf3_type sf3_type;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // (c0 o0 v) o1 (c1)
+               const details::cov_base_node<Type>* cov = static_cast<details::cov_base_node<Type>*>(branch[0]);
+               const Type  c0 = cov->c();
+               const Type&  v = cov->v();
+               const Type  c1 = static_cast<details::literal_node<Type>*>(branch[1])->value();
+               const details::operator_type o0 = cov->operation();
+               const details::operator_type o1 = operation;
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               if (expr_gen.parser_->settings_.strength_reduction_enabled())
+               {
+                  // (c0 + v) + c1 --> (cov) (c0 + c1) + v
+                  if ((details::e_add == o0) && (details::e_add == o1))
+                  {
+                     exprtk_debug(("(c0 + v) + c1 --> (cov) (c0 + c1) + v\n"));
+
+                     return expr_gen.node_allocator_->
+                               template allocate_cr<typename details::cov_node<Type,details::add_op<Type> > >(c0 + c1, v);
+                  }
+                  // (c0 + v) - c1 --> (cov) (c0 - c1) + v
+                  else if ((details::e_add == o0) && (details::e_sub == o1))
+                  {
+                     exprtk_debug(("(c0 + v) - c1 --> (cov) (c0 - c1) + v\n"));
+
+                     return expr_gen.node_allocator_->
+                               template allocate_cr<typename details::cov_node<Type,details::add_op<Type> > >(c0 - c1, v);
+                  }
+                  // (c0 - v) + c1 --> (cov) (c0 + c1) - v
+                  else if ((details::e_sub == o0) && (details::e_add == o1))
+                  {
+                     exprtk_debug(("(c0 - v) + c1 --> (cov) (c0 + c1) - v\n"));
+
+                     return expr_gen.node_allocator_->
+                               template allocate_cr<typename details::cov_node<Type,details::sub_op<Type> > >(c0 + c1, v);
+                  }
+                  // (c0 - v) - c1 --> (cov) (c0 - c1) - v
+                  else if ((details::e_sub == o0) && (details::e_sub == o1))
+                  {
+                     exprtk_debug(("(c0 - v) - c1 --> (cov) (c0 - c1) - v\n"));
+
+                     return expr_gen.node_allocator_->
+                               template allocate_cr<typename details::cov_node<Type,details::sub_op<Type> > >(c0 - c1, v);
+                  }
+                  // (c0 * v) * c1 --> (cov) (c0 * c1) * v
+                  else if ((details::e_mul == o0) && (details::e_mul == o1))
+                  {
+                     exprtk_debug(("(c0 * v) * c1 --> (cov) (c0 * c1) * v\n"));
+
+                     return expr_gen.node_allocator_->
+                               template allocate_cr<typename details::cov_node<Type,details::mul_op<Type> > >(c0 * c1, v);
+                  }
+                  // (c0 * v) / c1 --> (cov) (c0 / c1) * v
+                  else if ((details::e_mul == o0) && (details::e_div == o1))
+                  {
+                     exprtk_debug(("(c0 * v) / c1 --> (cov) (c0 / c1) * v\n"));
+
+                     return expr_gen.node_allocator_->
+                               template allocate_cr<typename details::cov_node<Type,details::mul_op<Type> > >(c0 / c1, v);
+                  }
+                  // (c0 / v) * c1 --> (cov) (c0 * c1) / v
+                  else if ((details::e_div == o0) && (details::e_mul == o1))
+                  {
+                     exprtk_debug(("(c0 / v) * c1 --> (cov) (c0 * c1) / v\n"));
+
+                     return expr_gen.node_allocator_->
+                               template allocate_cr<typename details::cov_node<Type,details::div_op<Type> > >(c0 * c1, v);
+                  }
+                  // (c0 / v) / c1 --> (cov) (c0 / c1) / v
+                  else if ((details::e_div == o0) && (details::e_div == o1))
+                  {
+                     exprtk_debug(("(c0 / v) / c1 --> (cov) (c0 / c1) / v\n"));
+
+                     return expr_gen.node_allocator_->
+                               template allocate_cr<typename details::cov_node<Type,details::div_op<Type> > >(c0 / c1, v);
+                  }
+               }
+
+               const bool synthesis_result =
+                  synthesize_sf3ext_expression::template compile<ctype, vtype, ctype>
+                     (expr_gen, id(expr_gen, o0, o1), c0, v, c1, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+               else if (!expr_gen.valid_operator(o1,f1))
+                  return error_node();
+               else
+                  return node_type::allocate(*(expr_gen.node_allocator_), c0, v, c1, f0, f1);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0, const details::operator_type o1)
+            {
+               return details::build_string()
+                         << "(t" << expr_gen.to_str(o0)
+                         << "t)" << expr_gen.to_str(o1)
+                         << "t";
+            }
+         };
+
+         struct synthesize_covoc_expression1
+         {
+            typedef typename covoc_t::type1 node_type;
+            typedef typename covoc_t::sf3_type sf3_type;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // (c0) o0 (v o1 c1)
+               const details::voc_base_node<Type>* voc = static_cast<details::voc_base_node<Type>*>(branch[1]);
+               const Type  c0 = static_cast<details::literal_node<Type>*>(branch[0])->value();
+               const Type&  v = voc->v();
+               const Type  c1 = voc->c();
+               const details::operator_type o0 = operation;
+               const details::operator_type o1 = voc->operation();
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               if (expr_gen.parser_->settings_.strength_reduction_enabled())
+               {
+                  // (c0) + (v + c1) --> (cov) (c0 + c1) + v
+                  if ((details::e_add == o0) && (details::e_add == o1))
+                  {
+                     exprtk_debug(("(c0) + (v + c1) --> (cov) (c0 + c1) + v\n"));
+
+                     return expr_gen.node_allocator_->
+                               template allocate_cr<typename details::cov_node<Type,details::add_op<Type> > >(c0 + c1, v);
+                  }
+                  // (c0) + (v - c1) --> (cov) (c0 - c1) + v
+                  else if ((details::e_add == o0) && (details::e_sub == o1))
+                  {
+                     exprtk_debug(("(c0) + (v - c1) --> (cov) (c0 - c1) + v\n"));
+
+                     return expr_gen.node_allocator_->
+                               template allocate_cr<typename details::cov_node<Type,details::add_op<Type> > >(c0 - c1, v);
+                  }
+                  // (c0) - (v + c1) --> (cov) (c0 - c1) - v
+                  else if ((details::e_sub == o0) && (details::e_add == o1))
+                  {
+                     exprtk_debug(("(c0) - (v + c1) --> (cov) (c0 - c1) - v\n"));
+
+                     return expr_gen.node_allocator_->
+                               template allocate_cr<typename details::cov_node<Type,details::sub_op<Type> > >(c0 - c1, v);
+                  }
+                  // (c0) - (v - c1) --> (cov) (c0 + c1) - v
+                  else if ((details::e_sub == o0) && (details::e_sub == o1))
+                  {
+                     exprtk_debug(("(c0) - (v - c1) --> (cov) (c0 + c1) - v\n"));
+
+                     return expr_gen.node_allocator_->
+                               template allocate_cr<typename details::cov_node<Type,details::sub_op<Type> > >(c0 + c1, v);
+                  }
+                  // (c0) * (v * c1) --> (voc) v * (c0 * c1)
+                  else if ((details::e_mul == o0) && (details::e_mul == o1))
+                  {
+                     exprtk_debug(("(c0) * (v * c1) --> (voc) v * (c0 * c1)\n"));
+
+                     return expr_gen.node_allocator_->
+                               template allocate_cr<typename details::cov_node<Type,details::mul_op<Type> > >(c0 * c1, v);
+                  }
+                  // (c0) * (v / c1) --> (cov) (c0 / c1) * v
+                  else if ((details::e_mul == o0) && (details::e_div == o1))
+                  {
+                     exprtk_debug(("(c0) * (v / c1) --> (cov) (c0 / c1) * v\n"));
+
+                     return expr_gen.node_allocator_->
+                               template allocate_cr<typename details::cov_node<Type,details::mul_op<Type> > >(c0 / c1, v);
+                  }
+                  // (c0) / (v * c1) --> (cov) (c0 / c1) / v
+                  else if ((details::e_div == o0) && (details::e_mul == o1))
+                  {
+                     exprtk_debug(("(c0) / (v * c1) --> (cov) (c0 / c1) / v\n"));
+
+                     return expr_gen.node_allocator_->
+                               template allocate_cr<typename details::cov_node<Type,details::div_op<Type> > >(c0 / c1, v);
+                  }
+                  // (c0) / (v / c1) --> (cov) (c0 * c1) / v
+                  else if ((details::e_div == o0) && (details::e_div == o1))
+                  {
+                     exprtk_debug(("(c0) / (v / c1) --> (cov) (c0 * c1) / v\n"));
+
+                     return expr_gen.node_allocator_->
+                               template allocate_cr<typename details::cov_node<Type,details::div_op<Type> > >(c0 * c1, v);
+                  }
+               }
+
+               const bool synthesis_result =
+                  synthesize_sf3ext_expression::template compile<ctype, vtype, ctype>
+                     (expr_gen, id(expr_gen, o0, o1), c0, v, c1, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+               else if (!expr_gen.valid_operator(o1,f1))
+                  return error_node();
+               else
+                  return node_type::allocate(*(expr_gen.node_allocator_), c0, v, c1, f0, f1);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0, const details::operator_type o1)
+            {
+               return details::build_string()
+                         << "t"  << expr_gen.to_str(o0)
+                         << "(t" << expr_gen.to_str(o1)
+                         << "t)";
+            }
+         };
+
+         struct synthesize_cocov_expression0
+         {
+            typedef typename cocov_t::type0 node_type;
+            static inline expression_node_ptr process(expression_generator<Type>&, const details::operator_type&, expression_node_ptr (&)[2])
+            {
+               // (c0 o0 c1) o1 (v) - Not possible.
+               return error_node();
+            }
+         };
+
+         struct synthesize_cocov_expression1
+         {
+            typedef typename cocov_t::type1 node_type;
+            typedef typename cocov_t::sf3_type sf3_type;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // (c0) o0 (c1 o1 v)
+               const details::cov_base_node<Type>* cov = static_cast<details::cov_base_node<Type>*>(branch[1]);
+               const Type  c0 = static_cast<details::literal_node<Type>*>(branch[0])->value();
+               const Type  c1 = cov->c();
+               const Type&  v = cov->v();
+               const details::operator_type o0 = operation;
+               const details::operator_type o1 = cov->operation();
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               if (expr_gen.parser_->settings_.strength_reduction_enabled())
+               {
+                  // (c0) + (c1 + v) --> (cov) (c0 + c1) + v
+                  if ((details::e_add == o0) && (details::e_add == o1))
+                  {
+                     exprtk_debug(("(c0) + (c1 + v) --> (cov) (c0 + c1) + v\n"));
+
+                     return expr_gen.node_allocator_->
+                               template allocate_cr<typename details::cov_node<Type,details::add_op<Type> > >(c0 + c1, v);
+                  }
+                  // (c0) + (c1 - v) --> (cov) (c0 + c1) - v
+                  else if ((details::e_add == o0) && (details::e_sub == o1))
+                  {
+                     exprtk_debug(("(c0) + (c1 - v) --> (cov) (c0 + c1) - v\n"));
+
+                     return expr_gen.node_allocator_->
+                               template allocate_cr<typename details::cov_node<Type,details::sub_op<Type> > >(c0 + c1, v);
+                  }
+                  // (c0) - (c1 + v) --> (cov) (c0 - c1) - v
+                  else if ((details::e_sub == o0) && (details::e_add == o1))
+                  {
+                     exprtk_debug(("(c0) - (c1 + v) --> (cov) (c0 - c1) - v\n"));
+
+                     return expr_gen.node_allocator_->
+                               template allocate_cr<typename details::cov_node<Type,details::sub_op<Type> > >(c0 - c1, v);
+                  }
+                  // (c0) - (c1 - v) --> (cov) (c0 - c1) + v
+                  else if ((details::e_sub == o0) && (details::e_sub == o1))
+                  {
+                     exprtk_debug(("(c0) - (c1 - v) --> (cov) (c0 - c1) + v\n"));
+
+                     return expr_gen.node_allocator_->
+                               template allocate_cr<typename details::cov_node<Type,details::add_op<Type> > >(c0 - c1, v);
+                  }
+                  // (c0) * (c1 * v) --> (cov) (c0 * c1) * v
+                  else if ((details::e_mul == o0) && (details::e_mul == o1))
+                  {
+                     exprtk_debug(("(c0) * (c1 * v) --> (cov) (c0 * c1) * v\n"));
+
+                     return expr_gen.node_allocator_->
+                               template allocate_cr<typename details::cov_node<Type,details::mul_op<Type> > >(c0 * c1, v);
+                  }
+                  // (c0) * (c1 / v) --> (cov) (c0 * c1) / v
+                  else if ((details::e_mul == o0) && (details::e_div == o1))
+                  {
+                     exprtk_debug(("(c0) * (c1 / v) --> (cov) (c0 * c1) / v\n"));
+
+                     return expr_gen.node_allocator_->
+                               template allocate_cr<typename details::cov_node<Type,details::div_op<Type> > >(c0 * c1, v);
+                  }
+                  // (c0) / (c1 * v) --> (cov) (c0 / c1) / v
+                  else if ((details::e_div == o0) && (details::e_mul == o1))
+                  {
+                     exprtk_debug(("(c0) / (c1 * v) --> (cov) (c0 / c1) / v\n"));
+
+                     return expr_gen.node_allocator_->
+                               template allocate_cr<typename details::cov_node<Type,details::div_op<Type> > >(c0 / c1, v);
+                  }
+                  // (c0) / (c1 / v) --> (cov) (c0 / c1) * v
+                  else if ((details::e_div == o0) && (details::e_div == o1))
+                  {
+                     exprtk_debug(("(c0) / (c1 / v) --> (cov) (c0 / c1) * v\n"));
+
+                     return expr_gen.node_allocator_->
+                               template allocate_cr<typename details::cov_node<Type,details::mul_op<Type> > >(c0 / c1, v);
+                  }
+               }
+
+               const bool synthesis_result =
+                  synthesize_sf3ext_expression::template compile<ctype, ctype, vtype>
+                     (expr_gen, id(expr_gen, o0, o1), c0, c1, v, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+               else if (!expr_gen.valid_operator(o1,f1))
+                  return error_node();
+               else
+                  return node_type::allocate(*(expr_gen.node_allocator_), c0, c1, v, f0, f1);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen, const details::operator_type o0, const details::operator_type o1)
+            {
+               return details::build_string()
+                         << "t"  << expr_gen.to_str(o0)
+                         << "(t" << expr_gen.to_str(o1)
+                         << "t)";
+            }
+         };
+
+         struct synthesize_vococ_expression0
+         {
+            typedef typename vococ_t::type0 node_type;
+            typedef typename vococ_t::sf3_type sf3_type;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // (v o0 c0) o1 (c1)
+               const details::voc_base_node<Type>* voc = static_cast<details::voc_base_node<Type>*>(branch[0]);
+               const Type&  v = voc->v();
+               const Type& c0 = voc->c();
+               const Type& c1 = static_cast<details::literal_node<Type>*>(branch[1])->value();
+               const details::operator_type o0 = voc->operation();
+               const details::operator_type o1 = operation;
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               if (expr_gen.parser_->settings_.strength_reduction_enabled())
+               {
+                  // (v + c0) + c1 --> (voc) v + (c0 + c1)
+                  if ((details::e_add == o0) && (details::e_add == o1))
+                  {
+                     exprtk_debug(("(v + c0) + c1 --> (voc) v + (c0 + c1)\n"));
+
+                     return expr_gen.node_allocator_->
+                               template allocate_rc<typename details::voc_node<Type,details::add_op<Type> > >(v, c0 + c1);
+                  }
+                  // (v + c0) - c1 --> (voc) v + (c0 - c1)
+                  else if ((details::e_add == o0) && (details::e_sub == o1))
+                  {
+                     exprtk_debug(("(v + c0) - c1 --> (voc) v + (c0 - c1)\n"));
+
+                     return expr_gen.node_allocator_->
+                               template allocate_rc<typename details::voc_node<Type,details::add_op<Type> > >(v, c0 - c1);
+                  }
+                  // (v - c0) + c1 --> (voc) v - (c0 + c1)
+                  else if ((details::e_sub == o0) && (details::e_add == o1))
+                  {
+                     exprtk_debug(("(v - c0) + c1 --> (voc) v - (c0 + c1)\n"));
+
+                     return expr_gen.node_allocator_->
+                               template allocate_rc<typename details::voc_node<Type,details::add_op<Type> > >(v, c1 - c0);
+                  }
+                  // (v - c0) - c1 --> (voc) v - (c0 + c1)
+                  else if ((details::e_sub == o0) && (details::e_sub == o1))
+                  {
+                     exprtk_debug(("(v - c0) - c1 --> (voc) v - (c0 + c1)\n"));
+
+                     return expr_gen.node_allocator_->
+                               template allocate_rc<typename details::voc_node<Type,details::sub_op<Type> > >(v, c0 + c1);
+                  }
+                  // (v * c0) * c1 --> (voc) v * (c0 * c1)
+                  else if ((details::e_mul == o0) && (details::e_mul == o1))
+                  {
+                     exprtk_debug(("(v * c0) * c1 --> (voc) v * (c0 * c1)\n"));
+
+                     return expr_gen.node_allocator_->
+                               template allocate_rc<typename details::voc_node<Type,details::mul_op<Type> > >(v, c0 * c1);
+                  }
+                  // (v * c0) / c1 --> (voc) v * (c0 / c1)
+                  else if ((details::e_mul == o0) && (details::e_div == o1))
+                  {
+                     exprtk_debug(("(v * c0) / c1 --> (voc) v * (c0 / c1)\n"));
+
+                     return expr_gen.node_allocator_->
+                               template allocate_rc<typename details::voc_node<Type,details::mul_op<Type> > >(v, c0 / c1);
+                  }
+                  // (v / c0) * c1 --> (voc) v * (c1 / c0)
+                  else if ((details::e_div == o0) && (details::e_mul == o1))
+                  {
+                     exprtk_debug(("(v / c0) * c1 --> (voc) v * (c1 / c0)\n"));
+
+                     return expr_gen.node_allocator_->
+                               template allocate_rc<typename details::voc_node<Type,details::mul_op<Type> > >(v, c1 / c0);
+                  }
+                  // (v / c0) / c1 --> (voc) v / (c0 * c1)
+                  else if ((details::e_div == o0) && (details::e_div == o1))
+                  {
+                     exprtk_debug(("(v / c0) / c1 --> (voc) v / (c0 * c1)\n"));
+
+                     return expr_gen.node_allocator_->
+                               template allocate_rc<typename details::voc_node<Type,details::div_op<Type> > >(v, c0 * c1);
+                  }
+                  // (v ^ c0) ^ c1 --> (voc) v ^ (c0 * c1)
+                  else if ((details::e_pow == o0) && (details::e_pow == o1))
+                  {
+                     exprtk_debug(("(v ^ c0) ^ c1 --> (voc) v ^ (c0 * c1)\n"));
+
+                     return expr_gen.node_allocator_->
+                               template allocate_rc<typename details::voc_node<Type,details::pow_op<Type> > >(v, c0 * c1);
+                  }
+               }
+
+               const bool synthesis_result =
+                  synthesize_sf3ext_expression::template compile<vtype, ctype, ctype>
+                     (expr_gen, id(expr_gen, o0, o1), v, c0, c1, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+               else if (!expr_gen.valid_operator(o1,f1))
+                  return error_node();
+               else
+                  return node_type::allocate(*(expr_gen.node_allocator_), v, c0, c1, f0, f1);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0, const details::operator_type o1)
+            {
+               return details::build_string()
+                         << "(t" << expr_gen.to_str(o0)
+                         << "t)" << expr_gen.to_str(o1)
+                         << "t";
+            }
+         };
+
+         struct synthesize_vococ_expression1
+         {
+            typedef typename vococ_t::type0 node_type;
+
+            static inline expression_node_ptr process(expression_generator<Type>&, const details::operator_type&, expression_node_ptr (&)[2])
+            {
+               // (v) o0 (c0 o1 c1) - Not possible.
+               exprtk_debug(("(v) o0 (c0 o1 c1) - Not possible.\n"));
+               return error_node();
+            }
+         };
+
+         struct synthesize_vovovov_expression0
+         {
+            typedef typename vovovov_t::type0 node_type;
+            typedef typename vovovov_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // (v0 o0 v1) o1 (v2 o2 v3)
+               const details::vov_base_node<Type>* vov0 = static_cast<details::vov_base_node<Type>*>(branch[0]);
+               const details::vov_base_node<Type>* vov1 = static_cast<details::vov_base_node<Type>*>(branch[1]);
+               const Type& v0 = vov0->v0();
+               const Type& v1 = vov0->v1();
+               const Type& v2 = vov1->v0();
+               const Type& v3 = vov1->v1();
+               const details::operator_type o0 = vov0->operation();
+               const details::operator_type o1 = operation;
+               const details::operator_type o2 = vov1->operation();
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f2 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               if (expr_gen.parser_->settings_.strength_reduction_enabled())
+               {
+                  // (v0 / v1) * (v2 / v3) --> (vovovov) (v0 * v2) / (v1 * v3)
+                  if ((details::e_div == o0) && (details::e_mul == o1) && (details::e_div == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf4ext_expression::
+                           template compile<vtype,vtype,vtype,vtype>(expr_gen, "(t*t)/(t*t)", v0, v2, v1, v3, result);
+
+                     exprtk_debug(("(v0 / v1) * (v2 / v3) --> (vovovov) (v0 * v2) / (v1 * v3)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (v0 / v1) / (v2 / v3) --> (vovovov) (v0 * v3) / (v1 * v2)
+                  else if ((details::e_div == o0) && (details::e_div == o1) && (details::e_div == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf4ext_expression::
+                           template compile<vtype,vtype,vtype,vtype>(expr_gen, "(t*t)/(t*t)", v0, v3, v1, v2, result);
+
+                     exprtk_debug(("(v0 / v1) / (v2 / v3) --> (vovovov) (v0 * v3) / (v1 * v2)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (v0 + v1) / (v2 / v3) --> (vovovov) (v0 + v1) * (v3 / v2)
+                  else if ((details::e_add == o0) && (details::e_div == o1) && (details::e_div == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf4ext_expression::
+                           template compile<vtype,vtype,vtype,vtype>(expr_gen, "(t+t)*(t/t)", v0, v1, v3, v2, result);
+
+                     exprtk_debug(("(v0 + v1) / (v2 / v3) --> (vovovov) (v0 + v1) * (v3 / v2)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (v0 - v1) / (v2 / v3) --> (vovovov) (v0 + v1) * (v3 / v2)
+                  else if ((details::e_sub == o0) && (details::e_div == o1) && (details::e_div == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf4ext_expression::
+                           template compile<vtype,vtype,vtype,vtype>(expr_gen, "(t-t)*(t/t)", v0, v1, v3, v2, result);
+
+                     exprtk_debug(("(v0 - v1) / (v2 / v3) --> (vovovov) (v0 - v1) * (v3 / v2)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (v0 * v1) / (v2 / v3) --> (vovovov) ((v0 * v1) * v3) / v2
+                  else if ((details::e_mul == o0) && (details::e_div == o1) && (details::e_div == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf4ext_expression::
+                           template compile<vtype,vtype,vtype,vtype>(expr_gen, "((t*t)*t)/t", v0, v1, v3, v2, result);
+
+                     exprtk_debug(("(v0 * v1) / (v2 / v3) --> (vovovov) ((v0 * v1) * v3) / v2\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+               }
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), v0, v1, v2, v3, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+               else if (!expr_gen.valid_operator(o1,f1))
+                  return error_node();
+               else if (!expr_gen.valid_operator(o2,f2))
+                  return error_node();
+               else
+                  return node_type::allocate(*(expr_gen.node_allocator_), v0, v1, v2, v3, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "(t" << expr_gen.to_str(o0)
+                         << "t)" << expr_gen.to_str(o1)
+                         << "(t" << expr_gen.to_str(o2)
+                         << "t)";
+            }
+         };
+
+         struct synthesize_vovovoc_expression0
+         {
+            typedef typename vovovoc_t::type0 node_type;
+            typedef typename vovovoc_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // (v0 o0 v1) o1 (v2 o2 c)
+               const details::vov_base_node<Type>* vov = static_cast<details::vov_base_node<Type>*>(branch[0]);
+               const details::voc_base_node<Type>* voc = static_cast<details::voc_base_node<Type>*>(branch[1]);
+               const Type& v0 = vov->v0();
+               const Type& v1 = vov->v1();
+               const Type& v2 = voc->v ();
+               const Type   c = voc->c ();
+               const details::operator_type o0 = vov->operation();
+               const details::operator_type o1 = operation;
+               const details::operator_type o2 = voc->operation();
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f2 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               if (expr_gen.parser_->settings_.strength_reduction_enabled())
+               {
+                  // (v0 / v1) * (v2 / c) --> (vovovoc) (v0 * v2) / (v1 * c)
+                  if ((details::e_div == o0) && (details::e_mul == o1) && (details::e_div == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf4ext_expression::
+                           template compile<vtype,vtype,vtype,ctype>(expr_gen, "(t*t)/(t*t)", v0, v2, v1, c, result);
+
+                     exprtk_debug(("(v0 / v1) * (v2 / c) --> (vovovoc) (v0 * v2) / (v1 * c)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (v0 / v1) / (v2 / c) --> (vocovov) (v0 * c) / (v1 * v2)
+                  if ((details::e_div == o0) && (details::e_div == o1) && (details::e_div == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf4ext_expression::
+                           template compile<vtype,ctype,vtype,vtype>(expr_gen, "(t*t)/(t*t)", v0, c, v1, v2, result);
+
+                     exprtk_debug(("(v0 / v1) / (v2 / c) --> (vocovov) (v0 * c) / (v1 * v2)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+               }
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), v0, v1, v2, c, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+               else if (!expr_gen.valid_operator(o1,f1))
+                  return error_node();
+               else if (!expr_gen.valid_operator(o2,f2))
+                  return error_node();
+               else
+                  return node_type::allocate(*(expr_gen.node_allocator_), v0, v1, v2, c, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "(t" << expr_gen.to_str(o0)
+                         << "t)" << expr_gen.to_str(o1)
+                         << "(t" << expr_gen.to_str(o2)
+                         << "t)";
+            }
+         };
+
+         struct synthesize_vovocov_expression0
+         {
+            typedef typename vovocov_t::type0 node_type;
+            typedef typename vovocov_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // (v0 o0 v1) o1 (c o2 v2)
+               const details::vov_base_node<Type>* vov = static_cast<details::vov_base_node<Type>*>(branch[0]);
+               const details::cov_base_node<Type>* cov = static_cast<details::cov_base_node<Type>*>(branch[1]);
+               const Type& v0 = vov->v0();
+               const Type& v1 = vov->v1();
+               const Type& v2 = cov->v ();
+               const Type   c = cov->c ();
+               const details::operator_type o0 = vov->operation();
+               const details::operator_type o1 = operation;
+               const details::operator_type o2 = cov->operation();
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f2 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               if (expr_gen.parser_->settings_.strength_reduction_enabled())
+               {
+                  // (v0 / v1) * (c / v2) --> (vocovov) (v0 * c) / (v1 * v2)
+                  if ((details::e_div == o0) && (details::e_mul == o1) && (details::e_div == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf4ext_expression::
+                           template compile<vtype,ctype,vtype,vtype>(expr_gen, "(t*t)/(t*t)", v0, c, v1, v2, result);
+
+                     exprtk_debug(("(v0 / v1) * (c / v2) --> (vocovov) (v0 * c) / (v1 * v2)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (v0 / v1) / (c / v2) --> (vovovoc) (v0 * v2) / (v1 * c)
+                  if ((details::e_div == o0) && (details::e_div == o1) && (details::e_div == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf4ext_expression::
+                           template compile<vtype,vtype,vtype,ctype>(expr_gen, "(t*t)/(t*t)", v0, v2, v1, c, result);
+
+                     exprtk_debug(("(v0 / v1) / (c / v2) --> (vovovoc) (v0 * v2) / (v1 * c)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+               }
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), v0, v1, c, v2, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+               else if (!expr_gen.valid_operator(o1,f1))
+                  return error_node();
+               else if (!expr_gen.valid_operator(o2,f2))
+                  return error_node();
+               else
+                  return node_type::allocate(*(expr_gen.node_allocator_), v0, v1, c, v2, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "(t" << expr_gen.to_str(o0)
+                         << "t)" << expr_gen.to_str(o1)
+                         << "(t" << expr_gen.to_str(o2)
+                         << "t)";
+            }
+         };
+
+         struct synthesize_vocovov_expression0
+         {
+            typedef typename vocovov_t::type0 node_type;
+            typedef typename vocovov_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // (v0 o0 c) o1 (v1 o2 v2)
+               const details::voc_base_node<Type>* voc = static_cast<details::voc_base_node<Type>*>(branch[0]);
+               const details::vov_base_node<Type>* vov = static_cast<details::vov_base_node<Type>*>(branch[1]);
+               const Type   c = voc->c ();
+               const Type& v0 = voc->v ();
+               const Type& v1 = vov->v0();
+               const Type& v2 = vov->v1();
+               const details::operator_type o0 = voc->operation();
+               const details::operator_type o1 = operation;
+               const details::operator_type o2 = vov->operation();
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f2 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               if (expr_gen.parser_->settings_.strength_reduction_enabled())
+               {
+                  // (v0 / c) * (v1 / v2) --> (vovocov) (v0 * v1) / (c * v2)
+                  if ((details::e_div == o0) && (details::e_mul == o1) && (details::e_div == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf4ext_expression::
+                           template compile<vtype,vtype,ctype,vtype>(expr_gen, "(t*t)/(t*t)", v0, v1, c, v2, result);
+
+                     exprtk_debug(("(v0 / c) * (v1 / v2) --> (vovocov) (v0 * v1) / (c * v2)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (v0 / c) / (v1 / v2) --> (vovocov) (v0 * v2) / (c * v1)
+                  if ((details::e_div == o0) && (details::e_div == o1) && (details::e_div == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf4ext_expression::
+                           template compile<vtype,vtype,ctype,vtype>(expr_gen, "(t*t)/(t*t)", v0, v2, c, v1, result);
+
+                     exprtk_debug(("(v0 / c) / (v1 / v2) --> (vovocov) (v0 * v2) / (c * v1)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+               }
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), v0, c, v1, v2, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+               else if (!expr_gen.valid_operator(o1,f1))
+                  return error_node();
+               else if (!expr_gen.valid_operator(o2,f2))
+                  return error_node();
+               else
+                  return node_type::allocate(*(expr_gen.node_allocator_), v0, c, v1, v2, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "(t" << expr_gen.to_str(o0)
+                         << "t)" << expr_gen.to_str(o1)
+                         << "(t" << expr_gen.to_str(o2)
+                         << "t)";
+            }
+         };
+
+         struct synthesize_covovov_expression0
+         {
+            typedef typename covovov_t::type0 node_type;
+            typedef typename covovov_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // (c o0 v0) o1 (v1 o2 v2)
+               const details::cov_base_node<Type>* cov = static_cast<details::cov_base_node<Type>*>(branch[0]);
+               const details::vov_base_node<Type>* vov = static_cast<details::vov_base_node<Type>*>(branch[1]);
+               const Type   c = cov->c ();
+               const Type& v0 = cov->v ();
+               const Type& v1 = vov->v0();
+               const Type& v2 = vov->v1();
+               const details::operator_type o0 = cov->operation();
+               const details::operator_type o1 = operation;
+               const details::operator_type o2 = vov->operation();
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f2 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               if (expr_gen.parser_->settings_.strength_reduction_enabled())
+               {
+                  // (c / v0) * (v1 / v2) --> (covovov) (c * v1) / (v0 * v2)
+                  if ((details::e_div == o0) && (details::e_mul == o1) && (details::e_div == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf4ext_expression::
+                           template compile<ctype,vtype,vtype,vtype>(expr_gen, "(t*t)/(t*t)", c, v1, v0, v2, result);
+
+                     exprtk_debug(("(c / v0) * (v1 / v2) --> (covovov) (c * v1) / (v0 * v2)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (c / v0) / (v1 / v2) --> (covovov) (c * v2) / (v0 * v1)
+                  if ((details::e_div == o0) && (details::e_div == o1) && (details::e_div == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf4ext_expression::
+                           template compile<ctype,vtype,vtype,vtype>(expr_gen, "(t*t)/(t*t)", c, v2, v0, v1, result);
+
+                     exprtk_debug(("(c / v0) / (v1 / v2) --> (covovov) (c * v2) / (v0 * v1)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+               }
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), c, v0, v1, v2, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+               else if (!expr_gen.valid_operator(o1,f1))
+                  return error_node();
+               else if (!expr_gen.valid_operator(o2,f2))
+                  return error_node();
+               else
+                  return node_type::allocate(*(expr_gen.node_allocator_), c, v0, v1, v2, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "(t" << expr_gen.to_str(o0)
+                         << "t)" << expr_gen.to_str(o1)
+                         << "(t" << expr_gen.to_str(o2)
+                         << "t)";
+            }
+         };
+
+         struct synthesize_covocov_expression0
+         {
+            typedef typename covocov_t::type0 node_type;
+            typedef typename covocov_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // (c0 o0 v0) o1 (c1 o2 v1)
+               const details::cov_base_node<Type>* cov0 = static_cast<details::cov_base_node<Type>*>(branch[0]);
+               const details::cov_base_node<Type>* cov1 = static_cast<details::cov_base_node<Type>*>(branch[1]);
+               const Type  c0 = cov0->c();
+               const Type& v0 = cov0->v();
+               const Type  c1 = cov1->c();
+               const Type& v1 = cov1->v();
+               const details::operator_type o0 = cov0->operation();
+               const details::operator_type o1 = operation;
+               const details::operator_type o2 = cov1->operation();
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f2 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               if (expr_gen.parser_->settings_.strength_reduction_enabled())
+               {
+                  // (c0 + v0) + (c1 + v1) --> (covov) (c0 + c1) + v0 + v1
+                  if ((details::e_add == o0) && (details::e_add == o1) && (details::e_add == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, "(t+t)+t", (c0 + c1), v0, v1, result);
+
+                     exprtk_debug(("(c0 + v0) + (c1 + v1) --> (covov) (c0 + c1) + v0 + v1\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (c0 + v0) - (c1 + v1) --> (covov) (c0 - c1) + v0 - v1
+                  else if ((details::e_add == o0) && (details::e_sub == o1) && (details::e_add == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, "(t+t)-t", (c0 - c1), v0, v1, result);
+
+                     exprtk_debug(("(c0 + v0) - (c1 + v1) --> (covov) (c0 - c1) + v0 - v1\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (c0 - v0) - (c1 - v1) --> (covov) (c0 - c1) - v0 + v1
+                  else if ((details::e_sub == o0) && (details::e_sub == o1) && (details::e_sub == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, "(t-t)+t", (c0 - c1), v0, v1, result);
+
+                     exprtk_debug(("(c0 - v0) - (c1 - v1) --> (covov) (c0 - c1) - v0 + v1\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (c0 * v0) * (c1 * v1) --> (covov) (c0 * c1) * v0 * v1
+                  else if ((details::e_mul == o0) && (details::e_mul == o1) && (details::e_mul == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, "(t*t)*t", (c0 * c1), v0, v1, result);
+
+                     exprtk_debug(("(c0 * v0) * (c1 * v1) --> (covov) (c0 * c1) * v0 * v1\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (c0 * v0) / (c1 * v1) --> (covov) (c0 / c1) * (v0 / v1)
+                  else if ((details::e_mul == o0) && (details::e_div == o1) && (details::e_mul == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, "(t*t)/t", (c0 / c1), v0, v1, result);
+
+                     exprtk_debug(("(c0 * v0) / (c1 * v1) --> (covov) (c0 / c1) * (v0 / v1)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (c0 / v0) * (c1 / v1) --> (covov) (c0 * c1) / (v0 * v1)
+                  else if ((details::e_div == o0) && (details::e_mul == o1) && (details::e_div == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, "t/(t*t)", (c0 * c1), v0, v1, result);
+
+                     exprtk_debug(("(c0 / v0) * (c1 / v1) --> (covov) (c0 * c1) / (v0 * v1)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (c0 / v0) / (c1 / v1) --> (covov) ((c0 / c1) * v1) / v0
+                  else if ((details::e_div == o0) && (details::e_div == o1) && (details::e_div == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, "(t*t)/t", (c0 / c1), v1, v0, result);
+
+                     exprtk_debug(("(c0 / v0) / (c1 / v1) --> (covov) ((c0 / c1) * v1) / v0\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (c0 * v0) / (c1 / v1) --> (covov) (c0 / c1) * (v0 * v1)
+                  else if ((details::e_mul == o0) && (details::e_div == o1) && (details::e_div == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, "t*(t*t)", (c0 / c1), v0, v1, result);
+
+                     exprtk_debug(("(c0 * v0) / (c1 / v1) --> (covov) (c0 / c1) * (v0 * v1)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (c0 / v0) / (c1 * v1) --> (covov) (c0 / c1) / (v0 * v1)
+                  else if ((details::e_div == o0) && (details::e_div == o1) && (details::e_mul == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, "t/(t*t)", (c0 / c1), v0, v1, result);
+
+                     exprtk_debug(("(c0 / v0) / (c1 * v1) --> (covov) (c0 / c1) / (v0 * v1)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (c * v0) +/- (c * v1) --> (covov) c * (v0 +/- v1)
+                  else if (
+                            (std::equal_to<T>()(c0,c1)) &&
+                            (details::e_mul == o0)      &&
+                            (details::e_mul == o2)      &&
+                            (
+                              (details::e_add == o1) ||
+                              (details::e_sub == o1)
+                            )
+                          )
+                  {
+                     std::string specfunc;
+
+                     switch (o1)
+                     {
+                        case details::e_add : specfunc = "t*(t+t)"; break;
+                        case details::e_sub : specfunc = "t*(t-t)"; break;
+                        default             : return error_node();
+                     }
+
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype, vtype, vtype>(expr_gen, specfunc, c0, v0, v1, result);
+
+                     exprtk_debug(("(c * v0) +/- (c * v1) --> (covov) c * (v0 +/- v1)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+               }
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), c0, v0, c1, v1, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+               else if (!expr_gen.valid_operator(o1,f1))
+                  return error_node();
+               else if (!expr_gen.valid_operator(o2,f2))
+                  return error_node();
+               else
+                  return node_type::allocate(*(expr_gen.node_allocator_), c0, v0, c1, v1, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "(t" << expr_gen.to_str(o0)
+                         << "t)" << expr_gen.to_str(o1)
+                         << "(t" << expr_gen.to_str(o2)
+                         << "t)";
+            }
+         };
+
+         struct synthesize_vocovoc_expression0
+         {
+            typedef typename vocovoc_t::type0 node_type;
+            typedef typename vocovoc_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // (v0 o0 c0) o1 (v1 o2 c1)
+               const details::voc_base_node<Type>* voc0 = static_cast<details::voc_base_node<Type>*>(branch[0]);
+               const details::voc_base_node<Type>* voc1 = static_cast<details::voc_base_node<Type>*>(branch[1]);
+               const Type  c0 = voc0->c();
+               const Type& v0 = voc0->v();
+               const Type  c1 = voc1->c();
+               const Type& v1 = voc1->v();
+               const details::operator_type o0 = voc0->operation();
+               const details::operator_type o1 = operation;
+               const details::operator_type o2 = voc1->operation();
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f2 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               if (expr_gen.parser_->settings_.strength_reduction_enabled())
+               {
+                  // (v0 + c0) + (v1 + c1) --> (covov) (c0 + c1) + v0 + v1
+                  if ((details::e_add == o0) && (details::e_add == o1) && (details::e_add == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, "(t+t)+t", (c0 + c1), v0, v1, result);
+
+                     exprtk_debug(("(v0 + c0) + (v1 + c1) --> (covov) (c0 + c1) + v0 + v1\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (v0 + c0) - (v1 + c1) --> (covov) (c0 - c1) + v0 - v1
+                  else if ((details::e_add == o0) && (details::e_sub == o1) && (details::e_add == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, "(t+t)-t", (c0 - c1), v0, v1, result);
+
+                     exprtk_debug(("(v0 + c0) - (v1 + c1) --> (covov) (c0 - c1) + v0 - v1\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (v0 - c0) - (v1 - c1) --> (covov) (c1 - c0) + v0 - v1
+                  else if ((details::e_sub == o0) && (details::e_sub == o1) && (details::e_sub == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, "(t+t)-t", (c1 - c0), v0, v1, result);
+
+                     exprtk_debug(("(v0 - c0) - (v1 - c1) --> (covov) (c1 - c0) + v0 - v1\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (v0 * c0) * (v1 * c1) --> (covov) (c0 * c1) * v0 * v1
+                  else if ((details::e_mul == o0) && (details::e_mul == o1) && (details::e_mul == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, "(t*t)*t", (c0 * c1), v0, v1, result);
+
+                     exprtk_debug(("(v0 * c0) * (v1 * c1) --> (covov) (c0 * c1) * v0 * v1\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (v0 * c0) / (v1 * c1) --> (covov) (c0 / c1) * (v0 / v1)
+                  else if ((details::e_mul == o0) && (details::e_div == o1) && (details::e_mul == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, "(t*t)/t", (c0 / c1), v0, v1, result);
+
+                     exprtk_debug(("(v0 * c0) / (v1 * c1) --> (covov) (c0 / c1) * (v0 / v1)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (v0 / c0) * (v1 / c1) --> (covov) (1 / (c0 * c1)) * v0 * v1
+                  else if ((details::e_div == o0) && (details::e_mul == o1) && (details::e_div == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, "(t*t)*t", Type(1) / (c0 * c1), v0, v1, result);
+
+                     exprtk_debug(("(v0 / c0) * (v1 / c1) --> (covov) (1 / (c0 * c1)) * v0 * v1\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (v0 / c0) / (v1 / c1) --> (covov) ((c1 / c0) * v0) / v1
+                  else if ((details::e_div == o0) && (details::e_div == o1) && (details::e_div == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, "(t*t)/t", (c1 / c0), v0, v1, result);
+
+                     exprtk_debug(("(v0 / c0) / (v1 / c1) --> (covov) ((c1 / c0) * v0) / v1\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (v0 * c0) / (v1 / c1) --> (covov) (c0 * c1) * (v0 / v1)
+                  else if ((details::e_mul == o0) && (details::e_div == o1) && (details::e_div == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, "t*(t/t)", (c0 * c1), v0, v1, result);
+
+                     exprtk_debug(("(v0 * c0) / (v1 / c1) --> (covov) (c0 * c1) * (v0 / v1)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (v0 / c0) / (v1 * c1) --> (covov) (1 / (c0 * c1)) * v0 / v1
+                  else if ((details::e_div == o0) && (details::e_div == o1) && (details::e_mul == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, "t*(t/t)", Type(1) / (c0 * c1), v0, v1, result);
+
+                     exprtk_debug(("(v0 / c0) / (v1 * c1) --> (covov) (1 / (c0 * c1)) * v0 / v1\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (v0 / c0) * (v1 + c1) --> (vocovoc) (v0 * (1 / c0)) * (v1 + c1)
+                  else if ((details::e_div == o0) && (details::e_mul == o1) && (details::e_add == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf4ext_expression::
+                           template compile<vtype,ctype,vtype,ctype>(expr_gen, "(t*t)*(t+t)", v0, T(1) / c0, v1, c1, result);
+
+                     exprtk_debug(("(v0 / c0) * (v1 + c1) --> (vocovoc) (v0 * (1 / c0)) * (v1 + c1)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (v0 / c0) * (v1 - c1) --> (vocovoc) (v0 * (1 / c0)) * (v1 - c1)
+                  else if ((details::e_div == o0) && (details::e_mul == o1) && (details::e_sub == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf4ext_expression::
+                           template compile<vtype,ctype,vtype,ctype>(expr_gen, "(t*t)*(t-t)", v0, T(1) / c0, v1, c1, result);
+
+                     exprtk_debug(("(v0 / c0) * (v1 - c1) --> (vocovoc) (v0 * (1 / c0)) * (v1 - c1)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (v0 * c) +/- (v1 * c) --> (covov) c * (v0 +/- v1)
+                  else if (
+                            (std::equal_to<T>()(c0,c1)) &&
+                            (details::e_mul == o0)      &&
+                            (details::e_mul == o2)      &&
+                            (
+                              (details::e_add == o1) ||
+                              (details::e_sub == o1)
+                            )
+                          )
+                  {
+                     std::string specfunc;
+
+                     switch (o1)
+                     {
+                        case details::e_add : specfunc = "t*(t+t)"; break;
+                        case details::e_sub : specfunc = "t*(t-t)"; break;
+                        default             : return error_node();
+                     }
+
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, specfunc, c0, v0, v1, result);
+
+                     exprtk_debug(("(v0 * c) +/- (v1 * c) --> (covov) c * (v0 +/- v1)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (v0 / c) +/- (v1 / c) --> (vovoc) (v0 +/- v1) / c
+                  else if (
+                            (std::equal_to<T>()(c0,c1)) &&
+                            (details::e_div == o0)      &&
+                            (details::e_div == o2)      &&
+                            (
+                              (details::e_add == o1) ||
+                              (details::e_sub == o1)
+                            )
+                          )
+                  {
+                     std::string specfunc;
+
+                     switch (o1)
+                     {
+                        case details::e_add : specfunc = "(t+t)/t"; break;
+                        case details::e_sub : specfunc = "(t-t)/t"; break;
+                        default             : return error_node();
+                     }
+
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<vtype,vtype,ctype>(expr_gen, specfunc, v0, v1, c0, result);
+
+                     exprtk_debug(("(v0 / c) +/- (v1 / c) --> (vovoc) (v0 +/- v1) / c\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+               }
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), v0, c0, v1, c1, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+               else if (!expr_gen.valid_operator(o1,f1))
+                  return error_node();
+               else if (!expr_gen.valid_operator(o2,f2))
+                  return error_node();
+               else
+                  return node_type::allocate(*(expr_gen.node_allocator_), v0, c0, v1, c1, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "(t" << expr_gen.to_str(o0)
+                         << "t)" << expr_gen.to_str(o1)
+                         << "(t" << expr_gen.to_str(o2)
+                         << "t)";
+            }
+         };
+
+         struct synthesize_covovoc_expression0
+         {
+            typedef typename covovoc_t::type0 node_type;
+            typedef typename covovoc_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // (c0 o0 v0) o1 (v1 o2 c1)
+               const details::cov_base_node<Type>* cov = static_cast<details::cov_base_node<Type>*>(branch[0]);
+               const details::voc_base_node<Type>* voc = static_cast<details::voc_base_node<Type>*>(branch[1]);
+               const Type  c0 = cov->c();
+               const Type& v0 = cov->v();
+               const Type  c1 = voc->c();
+               const Type& v1 = voc->v();
+               const details::operator_type o0 = cov->operation();
+               const details::operator_type o1 = operation;
+               const details::operator_type o2 = voc->operation();
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f2 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               if (expr_gen.parser_->settings_.strength_reduction_enabled())
+               {
+                  // (c0 + v0) + (v1 + c1) --> (covov) (c0 + c1) + v0 + v1
+                  if ((details::e_add == o0) && (details::e_add == o1) && (details::e_add == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, "(t+t)+t", (c0 + c1), v0, v1, result);
+
+                     exprtk_debug(("(c0 + v0) + (v1 + c1) --> (covov) (c0 + c1) + v0 + v1\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (c0 + v0) - (v1 + c1) --> (covov) (c0 - c1) + v0 - v1
+                  else if ((details::e_add == o0) && (details::e_sub == o1) && (details::e_add == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, "(t+t)-t", (c0 - c1), v0, v1, result);
+
+                     exprtk_debug(("(c0 + v0) - (v1 + c1) --> (covov) (c0 - c1) + v0 - v1\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (c0 - v0) - (v1 - c1) --> (covov) (c0 + c1) - v0 - v1
+                  else if ((details::e_sub == o0) && (details::e_sub == o1) && (details::e_sub == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, "t-(t+t)", (c0 + c1), v0, v1, result);
+
+                     exprtk_debug(("(c0 - v0) - (v1 - c1) --> (covov) (c0 + c1) - v0 - v1\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (c0 * v0) * (v1 * c1) --> (covov) (c0 * c1) * v0 * v1
+                  else if ((details::e_mul == o0) && (details::e_mul == o1) && (details::e_mul == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, "(t*t)*t", (c0 * c1), v0, v1, result);
+
+                     exprtk_debug(("(c0 * v0) * (v1 * c1) --> (covov) (c0 * c1) * v0 * v1\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (c0 * v0) / (v1 * c1) --> (covov) (c0 / c1) * (v0 / v1)
+                  else if ((details::e_mul == o0) && (details::e_div == o1) && (details::e_mul == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, "(t*t)/t", (c0 / c1), v0, v1, result);
+
+                     exprtk_debug(("(c0 * v0) / (v1 * c1) --> (covov) (c0 / c1) * (v0 / v1)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (c0 / v0) * (v1 / c1) --> (covov) (c0 / c1) * (v1 / v0)
+                  else if ((details::e_div == o0) && (details::e_mul == o1) && (details::e_div == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, "t*(t/t)", (c0 / c1), v1, v0, result);
+
+                     exprtk_debug(("(c0 / v0) * (v1 / c1) --> (covov) (c0 / c1) * (v1 / v0)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (c0 / v0) / (v1 / c1) --> (covov) (c0 * c1) / (v0 * v1)
+                  else if ((details::e_div == o0) && (details::e_div == o1) && (details::e_div == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, "t/(t*t)", (c0 * c1), v0, v1, result);
+
+                     exprtk_debug(("(c0 / v0) / (v1 / c1) --> (covov) (c0 * c1) / (v0 * v1)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (c0 * v0) / (v1 / c1) --> (covov) (c0 * c1) * (v0 / v1)
+                  else if ((details::e_mul == o0) && (details::e_div == o1) && (details::e_div == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, "(t*t)/t", (c0 * c1), v0, v1, result);
+
+                     exprtk_debug(("(c0 * v0) / (v1 / c1) --> (covov) (c0 * c1) * (v0 / v1)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (c0 / v0) / (v1 * c1) --> (covov) (c0 / c1) / (v0 * v1)
+                  else if ((details::e_div == o0) && (details::e_div == o1) && (details::e_mul == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, "t/(t*t)", (c0 / c1), v0, v1, result);
+
+                     exprtk_debug(("(c0 / v0) / (v1 * c1) --> (covov) (c0 / c1) / (v0 * v1)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (c * v0) +/- (v1 * c) --> (covov) c * (v0 +/- v1)
+                  else if (
+                            (std::equal_to<T>()(c0,c1)) &&
+                            (details::e_mul == o0)      &&
+                            (details::e_mul == o2)      &&
+                            (
+                              (details::e_add == o1) ||
+                              (details::e_sub == o1)
+                            )
+                          )
+                  {
+                     std::string specfunc;
+
+                     switch (o1)
+                     {
+                        case details::e_add : specfunc = "t*(t+t)"; break;
+                        case details::e_sub : specfunc = "t*(t-t)"; break;
+                        default             : return error_node();
+                     }
+
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen,specfunc, c0, v0, v1, result);
+
+                     exprtk_debug(("(c * v0) +/- (v1 * c) --> (covov) c * (v0 +/- v1)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+               }
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), c0, v0, v1, c1, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+               else if (!expr_gen.valid_operator(o1,f1))
+                  return error_node();
+               else if (!expr_gen.valid_operator(o2,f2))
+                  return error_node();
+               else
+                  return node_type::allocate(*(expr_gen.node_allocator_), c0, v0, v1, c1, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "(t" << expr_gen.to_str(o0)
+                         << "t)" << expr_gen.to_str(o1)
+                         << "(t" << expr_gen.to_str(o2)
+                         << "t)";
+            }
+         };
+
+         struct synthesize_vococov_expression0
+         {
+            typedef typename vococov_t::type0 node_type;
+            typedef typename vococov_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // (v0 o0 c0) o1 (c1 o2 v1)
+               const details::voc_base_node<Type>* voc = static_cast<details::voc_base_node<Type>*>(branch[0]);
+               const details::cov_base_node<Type>* cov = static_cast<details::cov_base_node<Type>*>(branch[1]);
+               const Type  c0 = voc->c();
+               const Type& v0 = voc->v();
+               const Type  c1 = cov->c();
+               const Type& v1 = cov->v();
+               const details::operator_type o0 = voc->operation();
+               const details::operator_type o1 = operation;
+               const details::operator_type o2 = cov->operation();
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f2 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               if (expr_gen.parser_->settings_.strength_reduction_enabled())
+               {
+                  // (v0 + c0) + (c1 + v1) --> (covov) (c0 + c1) + v0 + v1
+                  if ((details::e_add == o0) && (details::e_add == o1) && (details::e_add == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, "(t+t)+t", (c0 + c1), v0, v1, result);
+
+                     exprtk_debug(("(v0 + c0) + (c1 + v1) --> (covov) (c0 + c1) + v0 + v1\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (v0 + c0) - (c1 + v1) --> (covov) (c0 - c1) + v0 - v1
+                  else if ((details::e_add == o0) && (details::e_sub == o1) && (details::e_add == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, "(t+t)-t", (c0 - c1), v0, v1, result);
+
+                     exprtk_debug(("(v0 + c0) - (c1 + v1) --> (covov) (c0 - c1) + v0 - v1\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (v0 - c0) - (c1 - v1) --> (vovoc) v0 + v1 - (c1 + c0)
+                  else if ((details::e_sub == o0) && (details::e_sub == o1) && (details::e_sub == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<vtype,vtype,ctype>(expr_gen, "(t+t)-t", v0, v1, (c1 + c0), result);
+
+                     exprtk_debug(("(v0 - c0) - (c1 - v1) --> (vovoc) v0 + v1 - (c1 + c0)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (v0 * c0) * (c1 * v1) --> (covov) (c0 * c1) * v0 * v1
+                  else if ((details::e_mul == o0) && (details::e_mul == o1) && (details::e_mul == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, "(t*t)*t", (c0 * c1), v0, v1, result);
+
+                     exprtk_debug(("(v0 * c0) * (c1 * v1) --> (covov) (c0 * c1) * v0 * v1\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (v0 * c0) / (c1 * v1) --> (covov) (c0 / c1) * (v0 * v1)
+                  else if ((details::e_mul == o0) && (details::e_div == o1) && (details::e_mul == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, "(t*t)/t", (c0 / c1), v0, v1, result);
+
+                     exprtk_debug(("(v0 * c0) / (c1 * v1) --> (covov) (c0 / c1) * (v0 * v1)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (v0 / c0) * (c1 / v1) --> (covov) (c1 / c0) * (v0 / v1)
+                  else if ((details::e_div == o0) && (details::e_mul == o1) && (details::e_div == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, "(t*t)/t", (c1 / c0), v0, v1, result);
+
+                     exprtk_debug(("(v0 / c0) * (c1 / v1) --> (covov) (c1 / c0) * (v0 / v1)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (v0 * c0) / (c1 / v1) --> (covov) (c0 / c1) * (v0 * v1)
+                  else if ((details::e_mul == o0) && (details::e_div == o1) && (details::e_div == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, "(t*t)*t", (c0 / c1), v0, v1, result);
+
+                     exprtk_debug(("(v0 * c0) / (c1 / v1) --> (covov) (c0 / c1) * (v0 * v1)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (v0 / c0) / (c1 * v1) --> (covov) (1 / (c0 * c1)) * (v0 / v1)
+                  else if ((details::e_div == o0) && (details::e_div == o1) && (details::e_mul == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, "(t*t)/t", Type(1) / (c0 * c1), v0, v1, result);
+
+                     exprtk_debug(("(v0 / c0) / (c1 * v1) --> (covov) (1 / (c0 * c1)) * (v0 / v1)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (v0 / c0) / (c1 / v1) --> (vovoc) (v0 * v1) * (1 / (c0 * c1))
+                  else if ((details::e_div == o0) && (details::e_div == o1) && (details::e_div == o2))
+                  {
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<vtype,vtype,ctype>(expr_gen, "(t*t)*t", v0, v1, Type(1) / (c0 * c1), result);
+
+                     exprtk_debug(("(v0 / c0) / (c1 / v1) --> (vovoc) (v0 * v1) * (1 / (c0 * c1))\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+                  // (v0 * c) +/- (c * v1) --> (covov) c * (v0 +/- v1)
+                  else if (
+                            (std::equal_to<T>()(c0,c1)) &&
+                            (details::e_mul == o0)      &&
+                            (details::e_mul == o2)      &&
+                            (
+                              (details::e_add == o1) || (details::e_sub == o1)
+                            )
+                          )
+                  {
+                     std::string specfunc;
+
+                     switch (o1)
+                     {
+                        case details::e_add : specfunc = "t*(t+t)"; break;
+                        case details::e_sub : specfunc = "t*(t-t)"; break;
+                        default             : return error_node();
+                     }
+
+                     const bool synthesis_result =
+                        synthesize_sf3ext_expression::
+                           template compile<ctype,vtype,vtype>(expr_gen, specfunc, c0, v0, v1, result);
+
+                     exprtk_debug(("(v0 * c) +/- (c * v1) --> (covov) c * (v0 +/- v1)\n"));
+
+                     return (synthesis_result) ? result : error_node();
+                  }
+               }
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), v0, c0, c1, v1, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+               else if (!expr_gen.valid_operator(o1,f1))
+                  return error_node();
+               else if (!expr_gen.valid_operator(o2,f2))
+                  return error_node();
+               else
+                  return node_type::allocate(*(expr_gen.node_allocator_), v0, c0, c1, v1, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "(t" << expr_gen.to_str(o0)
+                         << "t)" << expr_gen.to_str(o1)
+                         << "(t" << expr_gen.to_str(o2)
+                         << "t)";
+            }
+         };
+
+         struct synthesize_vovovov_expression1
+         {
+            typedef typename vovovov_t::type1 node_type;
+            typedef typename vovovov_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // v0 o0 (v1 o1 (v2 o2 v3))
+               typedef typename synthesize_vovov_expression1::node_type lcl_vovov_t;
+
+               const lcl_vovov_t* vovov = static_cast<const lcl_vovov_t*>(branch[1]);
+               const Type& v0 = static_cast<details::variable_node<Type>*>(branch[0])->ref();
+               const Type& v1 = vovov->t0();
+               const Type& v2 = vovov->t1();
+               const Type& v3 = vovov->t2();
+               const details::operator_type o0 = operation;
+               const details::operator_type o1 = expr_gen.get_operator(vovov->f0());
+               const details::operator_type o2 = expr_gen.get_operator(vovov->f1());
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = vovov->f0();
+               binary_functor_t f2 = vovov->f1();
+
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               if (synthesize_sf4ext_expression::template compile<T0,T1,T2,T3>(expr_gen,id(expr_gen,o0,o1,o2),v0,v1,v2,v3,result))
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+
+               exprtk_debug(("v0 o0 (v1 o1 (v2 o2 v3))\n"));
+
+               return node_type::allocate(*(expr_gen.node_allocator_),v0,v1,v2,v3,f0,f1,f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "t"  << expr_gen.to_str(o0)
+                         << "(t" << expr_gen.to_str(o1)
+                         << "(t" << expr_gen.to_str(o2)
+                         << "t))";
+            }
+         };
+
+         struct synthesize_vovovoc_expression1
+         {
+            typedef typename vovovoc_t::type1 node_type;
+            typedef typename vovovoc_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // v0 o0 (v1 o1 (v2 o2 c))
+               typedef typename synthesize_vovoc_expression1::node_type lcl_vovoc_t;
+
+               const lcl_vovoc_t* vovoc = static_cast<const lcl_vovoc_t*>(branch[1]);
+               const Type& v0 = static_cast<details::variable_node<Type>*>(branch[0])->ref();
+               const Type& v1 = vovoc->t0();
+               const Type& v2 = vovoc->t1();
+               const Type   c = vovoc->t2();
+               const details::operator_type o0 = operation;
+               const details::operator_type o1 = expr_gen.get_operator(vovoc->f0());
+               const details::operator_type o2 = expr_gen.get_operator(vovoc->f1());
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = vovoc->f0();
+               binary_functor_t f2 = vovoc->f1();
+
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), v0, v1, v2, c, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+
+               exprtk_debug(("v0 o0 (v1 o1 (v2 o2 c))\n"));
+
+               return node_type::allocate(*(expr_gen.node_allocator_), v0, v1, v2, c, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "t"  << expr_gen.to_str(o0)
+                         << "(t" << expr_gen.to_str(o1)
+                         << "(t" << expr_gen.to_str(o2)
+                         << "t))";
+            }
+         };
+
+         struct synthesize_vovocov_expression1
+         {
+            typedef typename vovocov_t::type1 node_type;
+            typedef typename vovocov_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // v0 o0 (v1 o1 (c o2 v2))
+               typedef typename synthesize_vocov_expression1::node_type lcl_vocov_t;
+
+               const lcl_vocov_t* vocov = static_cast<const lcl_vocov_t*>(branch[1]);
+               const Type& v0 = static_cast<details::variable_node<Type>*>(branch[0])->ref();
+               const Type& v1 = vocov->t0();
+               const Type   c = vocov->t1();
+               const Type& v2 = vocov->t2();
+               const details::operator_type o0 = operation;
+               const details::operator_type o1 = expr_gen.get_operator(vocov->f0());
+               const details::operator_type o2 = expr_gen.get_operator(vocov->f1());
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = vocov->f0();
+               binary_functor_t f2 = vocov->f1();
+
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), v0, v1, c, v2, result);
+
+               if (synthesis_result)
+                  return result;
+               if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+
+               exprtk_debug(("v0 o0 (v1 o1 (c o2 v2))\n"));
+
+               return node_type::allocate(*(expr_gen.node_allocator_), v0, v1, c, v2, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "t"  << expr_gen.to_str(o0)
+                         << "(t" << expr_gen.to_str(o1)
+                         << "(t" << expr_gen.to_str(o2)
+                         << "t))";
+            }
+         };
+
+         struct synthesize_vocovov_expression1
+         {
+            typedef typename vocovov_t::type1 node_type;
+            typedef typename vocovov_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // v0 o0 (c o1 (v1 o2 v2))
+               typedef typename synthesize_covov_expression1::node_type lcl_covov_t;
+
+               const lcl_covov_t* covov = static_cast<const lcl_covov_t*>(branch[1]);
+               const Type& v0 = static_cast<details::variable_node<Type>*>(branch[0])->ref();
+               const Type   c = covov->t0();
+               const Type& v1 = covov->t1();
+               const Type& v2 = covov->t2();
+               const details::operator_type o0 = operation;
+               const details::operator_type o1 = expr_gen.get_operator(covov->f0());
+               const details::operator_type o2 = expr_gen.get_operator(covov->f1());
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = covov->f0();
+               binary_functor_t f2 = covov->f1();
+
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), v0, c, v1, v2, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+
+               exprtk_debug(("v0 o0 (c o1 (v1 o2 v2))\n"));
+
+               return node_type::allocate(*(expr_gen.node_allocator_), v0, c, v1, v2, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "t"  << expr_gen.to_str(o0)
+                         << "(t" << expr_gen.to_str(o1)
+                         << "(t" << expr_gen.to_str(o2)
+                         << "t))";
+            }
+         };
+
+         struct synthesize_covovov_expression1
+         {
+            typedef typename covovov_t::type1 node_type;
+            typedef typename covovov_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // c o0 (v0 o1 (v1 o2 v2))
+               typedef typename synthesize_vovov_expression1::node_type lcl_vovov_t;
+
+               const lcl_vovov_t* vovov = static_cast<const lcl_vovov_t*>(branch[1]);
+               const Type   c = static_cast<details::literal_node<Type>*>(branch[0])->value();
+               const Type& v0 = vovov->t0();
+               const Type& v1 = vovov->t1();
+               const Type& v2 = vovov->t2();
+               const details::operator_type o0 = operation;
+               const details::operator_type o1 = expr_gen.get_operator(vovov->f0());
+               const details::operator_type o2 = expr_gen.get_operator(vovov->f1());
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = vovov->f0();
+               binary_functor_t f2 = vovov->f1();
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), c, v0, v1, v2, result);
+
+               if (synthesis_result)
+                  return result;
+               if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+
+               exprtk_debug(("c o0 (v0 o1 (v1 o2 v2))\n"));
+
+               return node_type::allocate(*(expr_gen.node_allocator_), c, v0, v1, v2, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "t"  << expr_gen.to_str(o0)
+                         << "(t" << expr_gen.to_str(o1)
+                         << "(t" << expr_gen.to_str(o2)
+                         << "t))";
+            }
+         };
+
+         struct synthesize_covocov_expression1
+         {
+            typedef typename covocov_t::type1 node_type;
+            typedef typename covocov_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // c0 o0 (v0 o1 (c1 o2 v1))
+               typedef typename synthesize_vocov_expression1::node_type lcl_vocov_t;
+
+               const lcl_vocov_t* vocov = static_cast<const lcl_vocov_t*>(branch[1]);
+               const Type  c0 = static_cast<details::literal_node<Type>*>(branch[0])->value();
+               const Type& v0 = vocov->t0();
+               const Type  c1 = vocov->t1();
+               const Type& v1 = vocov->t2();
+               const details::operator_type o0 = operation;
+               const details::operator_type o1 = expr_gen.get_operator(vocov->f0());
+               const details::operator_type o2 = expr_gen.get_operator(vocov->f1());
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = vocov->f0();
+               binary_functor_t f2 = vocov->f1();
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), c0, v0, c1, v1, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+
+               exprtk_debug(("c0 o0 (v0 o1 (c1 o2 v1))\n"));
+
+               return node_type::allocate(*(expr_gen.node_allocator_), c0, v0, c1, v1, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "t"  << expr_gen.to_str(o0)
+                         << "(t" << expr_gen.to_str(o1)
+                         << "(t" << expr_gen.to_str(o2)
+                         << "t))";
+            }
+         };
+
+         struct synthesize_vocovoc_expression1
+         {
+            typedef typename vocovoc_t::type1 node_type;
+            typedef typename vocovoc_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // v0 o0 (c0 o1 (v1 o2 c2))
+               typedef typename synthesize_covoc_expression1::node_type lcl_covoc_t;
+
+               const lcl_covoc_t* covoc = static_cast<const lcl_covoc_t*>(branch[1]);
+               const Type& v0 = static_cast<details::variable_node<Type>*>(branch[0])->ref();
+               const Type  c0 = covoc->t0();
+               const Type& v1 = covoc->t1();
+               const Type  c1 = covoc->t2();
+               const details::operator_type o0 = operation;
+               const details::operator_type o1 = expr_gen.get_operator(covoc->f0());
+               const details::operator_type o2 = expr_gen.get_operator(covoc->f1());
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = covoc->f0();
+               binary_functor_t f2 = covoc->f1();
+
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), v0, c0, v1, c1, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+
+               exprtk_debug(("v0 o0 (c0 o1 (v1 o2 c2))\n"));
+
+               return node_type::allocate(*(expr_gen.node_allocator_), v0, c0, v1, c1, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "t"  << expr_gen.to_str(o0)
+                         << "(t" << expr_gen.to_str(o1)
+                         << "(t" << expr_gen.to_str(o2)
+                         << "t))";
+            }
+         };
+
+         struct synthesize_covovoc_expression1
+         {
+            typedef typename covovoc_t::type1 node_type;
+            typedef typename covovoc_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // c0 o0 (v0 o1 (v1 o2 c1))
+               typedef typename synthesize_vovoc_expression1::node_type lcl_vovoc_t;
+
+               const lcl_vovoc_t* vovoc = static_cast<const lcl_vovoc_t*>(branch[1]);
+               const Type  c0 = static_cast<details::literal_node<Type>*>(branch[0])->value();
+               const Type& v0 = vovoc->t0();
+               const Type& v1 = vovoc->t1();
+               const Type  c1 = vovoc->t2();
+               const details::operator_type o0 = operation;
+               const details::operator_type o1 = expr_gen.get_operator(vovoc->f0());
+               const details::operator_type o2 = expr_gen.get_operator(vovoc->f1());
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = vovoc->f0();
+               binary_functor_t f2 = vovoc->f1();
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), c0, v0, v1, c1, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+
+               exprtk_debug(("c0 o0 (v0 o1 (v1 o2 c1))\n"));
+
+               return node_type::allocate(*(expr_gen.node_allocator_), c0, v0, v1, c1, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "t"  << expr_gen.to_str(o0)
+                         << "(t" << expr_gen.to_str(o1)
+                         << "(t" << expr_gen.to_str(o2)
+                         << "t))";
+            }
+         };
+
+         struct synthesize_vococov_expression1
+         {
+            typedef typename vococov_t::type1 node_type;
+            typedef typename vococov_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // v0 o0 (c0 o1 (c1 o2 v1))
+               typedef typename synthesize_cocov_expression1::node_type lcl_cocov_t;
+
+               const lcl_cocov_t* cocov = static_cast<const lcl_cocov_t*>(branch[1]);
+               const Type& v0 = static_cast<details::variable_node<Type>*>(branch[0])->ref();
+               const Type  c0 = cocov->t0();
+               const Type  c1 = cocov->t1();
+               const Type& v1 = cocov->t2();
+               const details::operator_type o0 = operation;
+               const details::operator_type o1 = expr_gen.get_operator(cocov->f0());
+               const details::operator_type o2 = expr_gen.get_operator(cocov->f1());
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = cocov->f0();
+               binary_functor_t f2 = cocov->f1();
+
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), v0, c0, c1, v1, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+
+               exprtk_debug(("v0 o0 (c0 o1 (c1 o2 v1))\n"));
+
+               return node_type::allocate(*(expr_gen.node_allocator_), v0, c0, c1, v1, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "t"  << expr_gen.to_str(o0)
+                         << "(t" << expr_gen.to_str(o1)
+                         << "(t" << expr_gen.to_str(o2)
+                         << "t))";
+            }
+         };
+
+         struct synthesize_vovovov_expression2
+         {
+            typedef typename vovovov_t::type2 node_type;
+            typedef typename vovovov_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // v0 o0 ((v1 o1 v2) o2 v3)
+               typedef typename synthesize_vovov_expression0::node_type lcl_vovov_t;
+
+               const lcl_vovov_t* vovov = static_cast<const lcl_vovov_t*>(branch[1]);
+               const Type& v0 = static_cast<details::variable_node<Type>*>(branch[0])->ref();
+               const Type& v1 = vovov->t0();
+               const Type& v2 = vovov->t1();
+               const Type& v3 = vovov->t2();
+               const details::operator_type o0 = operation;
+               const details::operator_type o1 = expr_gen.get_operator(vovov->f0());
+               const details::operator_type o2 = expr_gen.get_operator(vovov->f1());
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = vovov->f0();
+               binary_functor_t f2 = vovov->f1();
+
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), v0, v1, v2, v3, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+
+               exprtk_debug(("v0 o0 ((v1 o1 v2) o2 v3)\n"));
+
+               return node_type::allocate(*(expr_gen.node_allocator_), v0, v1, v2, v3, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "t"   << expr_gen.to_str(o0)
+                         << "((t" << expr_gen.to_str(o1)
+                         << "t)"  << expr_gen.to_str(o2)
+                         << "t)";
+            }
+         };
+
+         struct synthesize_vovovoc_expression2
+         {
+            typedef typename vovovoc_t::type2 node_type;
+            typedef typename vovovoc_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // v0 o0 ((v1 o1 v2) o2 c)
+               typedef typename synthesize_vovoc_expression0::node_type lcl_vovoc_t;
+
+               const lcl_vovoc_t* vovoc = static_cast<const lcl_vovoc_t*>(branch[1]);
+               const Type& v0 = static_cast<details::variable_node<Type>*>(branch[0])->ref();
+               const Type& v1 = vovoc->t0();
+               const Type& v2 = vovoc->t1();
+               const Type   c = vovoc->t2();
+               const details::operator_type o0 = operation;
+               const details::operator_type o1 = expr_gen.get_operator(vovoc->f0());
+               const details::operator_type o2 = expr_gen.get_operator(vovoc->f1());
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = vovoc->f0();
+               binary_functor_t f2 = vovoc->f1();
+
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), v0, v1, v2, c, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+
+               exprtk_debug(("v0 o0 ((v1 o1 v2) o2 c)\n"));
+
+               return node_type::allocate(*(expr_gen.node_allocator_), v0, v1, v2, c, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "t"   << expr_gen.to_str(o0)
+                         << "((t" << expr_gen.to_str(o1)
+                         << "t)"  << expr_gen.to_str(o2)
+                         << "t)";
+            }
+         };
+
+         struct synthesize_vovocov_expression2
+         {
+            typedef typename vovocov_t::type2 node_type;
+            typedef typename vovocov_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // v0 o0 ((v1 o1 c) o2 v2)
+               typedef typename synthesize_vocov_expression0::node_type lcl_vocov_t;
+
+               const lcl_vocov_t* vocov = static_cast<const lcl_vocov_t*>(branch[1]);
+               const Type& v0 = static_cast<details::variable_node<Type>*>(branch[0])->ref();
+               const Type& v1 = vocov->t0();
+               const Type   c = vocov->t1();
+               const Type& v2 = vocov->t2();
+               const details::operator_type o0 = operation;
+               const details::operator_type o1 = expr_gen.get_operator(vocov->f0());
+               const details::operator_type o2 = expr_gen.get_operator(vocov->f1());
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = vocov->f0();
+               binary_functor_t f2 = vocov->f1();
+
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), v0, v1, c, v2, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+
+               exprtk_debug(("v0 o0 ((v1 o1 c) o2 v2)\n"));
+
+               return node_type::allocate(*(expr_gen.node_allocator_), v0, v1, c, v2, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "t"   << expr_gen.to_str(o0)
+                         << "((t" << expr_gen.to_str(o1)
+                         << "t)"  << expr_gen.to_str(o2)
+                         << "t)";
+            }
+         };
+
+         struct synthesize_vocovov_expression2
+         {
+            typedef typename vocovov_t::type2 node_type;
+            typedef typename vocovov_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // v0 o0 ((c o1 v1) o2 v2)
+               typedef typename synthesize_covov_expression0::node_type lcl_covov_t;
+
+               const lcl_covov_t* covov = static_cast<const lcl_covov_t*>(branch[1]);
+               const Type& v0 = static_cast<details::variable_node<Type>*>(branch[0])->ref();
+               const Type   c = covov->t0();
+               const Type& v1 = covov->t1();
+               const Type& v2 = covov->t2();
+               const details::operator_type o0 = operation;
+               const details::operator_type o1 = expr_gen.get_operator(covov->f0());
+               const details::operator_type o2 = expr_gen.get_operator(covov->f1());
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = covov->f0();
+               binary_functor_t f2 = covov->f1();
+
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), v0, c, v1, v2, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+
+               exprtk_debug(("v0 o0 ((c o1 v1) o2 v2)\n"));
+
+               return node_type::allocate(*(expr_gen.node_allocator_), v0, c, v1, v2, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "t"   << expr_gen.to_str(o0)
+                         << "((t" << expr_gen.to_str(o1)
+                         << "t)"  << expr_gen.to_str(o2)
+                         << "t)";
+            }
+         };
+
+         struct synthesize_covovov_expression2
+         {
+            typedef typename covovov_t::type2 node_type;
+            typedef typename covovov_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // c o0 ((v1 o1 v2) o2 v3)
+               typedef typename synthesize_vovov_expression0::node_type lcl_vovov_t;
+
+               const lcl_vovov_t* vovov = static_cast<const lcl_vovov_t*>(branch[1]);
+               const Type   c = static_cast<details::literal_node<Type>*>(branch[0])->value();
+               const Type& v0 = vovov->t0();
+               const Type& v1 = vovov->t1();
+               const Type& v2 = vovov->t2();
+               const details::operator_type o0 = operation;
+               const details::operator_type o1 = expr_gen.get_operator(vovov->f0());
+               const details::operator_type o2 = expr_gen.get_operator(vovov->f1());
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = vovov->f0();
+               binary_functor_t f2 = vovov->f1();
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), c, v0, v1, v2, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+
+               exprtk_debug(("c o0 ((v1 o1 v2) o2 v3)\n"));
+
+               return node_type::allocate(*(expr_gen.node_allocator_), c, v0, v1, v2, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "t"   << expr_gen.to_str(o0)
+                         << "((t" << expr_gen.to_str(o1)
+                         << "t)"  << expr_gen.to_str(o2)
+                         << "t)";
+            }
+        };
+
+         struct synthesize_covocov_expression2
+         {
+            typedef typename covocov_t::type2 node_type;
+            typedef typename covocov_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // c0 o0 ((v0 o1 c1) o2 v1)
+               typedef typename synthesize_vocov_expression0::node_type lcl_vocov_t;
+
+               const lcl_vocov_t* vocov = static_cast<const lcl_vocov_t*>(branch[1]);
+               const Type  c0 = static_cast<details::literal_node<Type>*>(branch[0])->value();
+               const Type& v0 = vocov->t0();
+               const Type  c1 = vocov->t1();
+               const Type& v1 = vocov->t2();
+               const details::operator_type o0 = operation;
+               const details::operator_type o1 = expr_gen.get_operator(vocov->f0());
+               const details::operator_type o2 = expr_gen.get_operator(vocov->f1());
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = vocov->f0();
+               binary_functor_t f2 = vocov->f1();
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), c0, v0, c1, v1, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+
+               exprtk_debug(("c0 o0 ((v0 o1 c1) o2 v1)\n"));
+
+               return node_type::allocate(*(expr_gen.node_allocator_), c0, v0, c1, v1, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "t"   << expr_gen.to_str(o0)
+                         << "((t" << expr_gen.to_str(o1)
+                         << "t)"  << expr_gen.to_str(o2)
+                         << "t)";
+            }
+         };
+
+         struct synthesize_vocovoc_expression2
+         {
+            typedef typename vocovoc_t::type2 node_type;
+            typedef typename vocovoc_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // v0 o0 ((c0 o1 v1) o2 c1)
+               typedef typename synthesize_covoc_expression0::node_type lcl_covoc_t;
+
+               const lcl_covoc_t* covoc = static_cast<const lcl_covoc_t*>(branch[1]);
+               const Type& v0 = static_cast<details::variable_node<Type>*>(branch[0])->ref();
+               const Type  c0 = covoc->t0();
+               const Type& v1 = covoc->t1();
+               const Type  c1 = covoc->t2();
+               const details::operator_type o0 = operation;
+               const details::operator_type o1 = expr_gen.get_operator(covoc->f0());
+               const details::operator_type o2 = expr_gen.get_operator(covoc->f1());
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = covoc->f0();
+               binary_functor_t f2 = covoc->f1();
+
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), v0, c0, v1, c1, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+
+               exprtk_debug(("v0 o0 ((c0 o1 v1) o2 c1)\n"));
+
+               return node_type::allocate(*(expr_gen.node_allocator_), v0, c0, v1, c1, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "t"   << expr_gen.to_str(o0)
+                         << "((t" << expr_gen.to_str(o1)
+                         << "t)"  << expr_gen.to_str(o2)
+                         << "t)";
+            }
+         };
+
+         struct synthesize_covovoc_expression2
+         {
+            typedef typename covovoc_t::type2 node_type;
+            typedef typename covovoc_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // c0 o0 ((v0 o1 v1) o2 c1)
+               typedef typename synthesize_vovoc_expression0::node_type lcl_vovoc_t;
+
+               const lcl_vovoc_t* vovoc = static_cast<const lcl_vovoc_t*>(branch[1]);
+               const Type  c0 = static_cast<details::literal_node<Type>*>(branch[0])->value();
+               const Type& v0 = vovoc->t0();
+               const Type& v1 = vovoc->t1();
+               const Type  c1 = vovoc->t2();
+               const details::operator_type o0 = operation;
+               const details::operator_type o1 = expr_gen.get_operator(vovoc->f0());
+               const details::operator_type o2 = expr_gen.get_operator(vovoc->f1());
+
+               binary_functor_t f0 = reinterpret_cast<binary_functor_t>(0);
+               binary_functor_t f1 = vovoc->f0();
+               binary_functor_t f2 = vovoc->f1();
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), c0, v0, v1, c1, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o0,f0))
+                  return error_node();
+
+               exprtk_debug(("c0 o0 ((v0 o1 v1) o2 c1)\n"));
+
+               return node_type::allocate(*(expr_gen.node_allocator_), c0, v0, v1, c1, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "t"   << expr_gen.to_str(o0)
+                         << "((t" << expr_gen.to_str(o1)
+                         << "t)"  << expr_gen.to_str(o2)
+                         << "t)";
+            }
+         };
+
+         struct synthesize_vococov_expression2
+         {
+            typedef typename vococov_t::type2 node_type;
+            static inline expression_node_ptr process(expression_generator<Type>&, const details::operator_type&, expression_node_ptr (&)[2])
+            {
+               // v0 o0 ((c0 o1 c1) o2 v1) - Not possible
+               exprtk_debug(("v0 o0 ((c0 o1 c1) o2 v1) - Not possible\n"));
+               return error_node();
+            }
+
+            static inline std::string id(expression_generator<Type>&,
+                                         const details::operator_type, const details::operator_type, const details::operator_type)
+            {
+               return "INVALID";
+            }
+         };
+
+         struct synthesize_vovovov_expression3
+         {
+            typedef typename vovovov_t::type3 node_type;
+            typedef typename vovovov_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // ((v0 o0 v1) o1 v2) o2 v3
+               typedef typename synthesize_vovov_expression0::node_type lcl_vovov_t;
+
+               const lcl_vovov_t* vovov = static_cast<const lcl_vovov_t*>(branch[0]);
+               const Type& v0 = vovov->t0();
+               const Type& v1 = vovov->t1();
+               const Type& v2 = vovov->t2();
+               const Type& v3 = static_cast<details::variable_node<Type>*>(branch[1])->ref();
+               const details::operator_type o0 = expr_gen.get_operator(vovov->f0());
+               const details::operator_type o1 = expr_gen.get_operator(vovov->f1());
+               const details::operator_type o2 = operation;
+
+               binary_functor_t f0 = vovov->f0();
+               binary_functor_t f1 = vovov->f1();
+               binary_functor_t f2 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+
+               expression_node_ptr result = error_node();
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), v0, v1, v2, v3, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o2,f2))
+                  return error_node();
+
+               exprtk_debug(("((v0 o0 v1) o1 v2) o2 v3\n"));
+
+               return node_type::allocate(*(expr_gen.node_allocator_), v0, v1, v2, v3, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "((t" << expr_gen.to_str(o0)
+                         << "t)"  << expr_gen.to_str(o1)
+                         << "t)"  << expr_gen.to_str(o2)
+                         << "t";
+            }
+         };
+
+         struct synthesize_vovovoc_expression3
+         {
+            typedef typename vovovoc_t::type3 node_type;
+            typedef typename vovovoc_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // ((v0 o0 v1) o1 v2) o2 c
+               typedef typename synthesize_vovov_expression0::node_type lcl_vovov_t;
+
+               const lcl_vovov_t* vovov = static_cast<const lcl_vovov_t*>(branch[0]);
+               const Type& v0 = vovov->t0();
+               const Type& v1 = vovov->t1();
+               const Type& v2 = vovov->t2();
+               const Type   c = static_cast<details::literal_node<Type>*>(branch[1])->value();
+               const details::operator_type o0 = expr_gen.get_operator(vovov->f0());
+               const details::operator_type o1 = expr_gen.get_operator(vovov->f1());
+               const details::operator_type o2 = operation;
+
+               binary_functor_t f0 = vovov->f0();
+               binary_functor_t f1 = vovov->f1();
+               binary_functor_t f2 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), v0, v1, v2, c, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o2,f2))
+                  return error_node();
+
+               exprtk_debug(("((v0 o0 v1) o1 v2) o2 c\n"));
+
+               return node_type::allocate(*(expr_gen.node_allocator_), v0, v1, v2, c, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "((t" << expr_gen.to_str(o0)
+                         << "t)"  << expr_gen.to_str(o1)
+                         << "t)"  << expr_gen.to_str(o2)
+                         << "t";
+            }
+         };
+
+         struct synthesize_vovocov_expression3
+         {
+            typedef typename vovocov_t::type3 node_type;
+            typedef typename vovocov_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // ((v0 o0 v1) o1 c) o2 v2
+               typedef typename synthesize_vovoc_expression0::node_type lcl_vovoc_t;
+
+               const lcl_vovoc_t* vovoc = static_cast<const lcl_vovoc_t*>(branch[0]);
+               const Type& v0 = vovoc->t0();
+               const Type& v1 = vovoc->t1();
+               const Type   c = vovoc->t2();
+               const Type& v2 = static_cast<details::variable_node<Type>*>(branch[1])->ref();
+               const details::operator_type o0 = expr_gen.get_operator(vovoc->f0());
+               const details::operator_type o1 = expr_gen.get_operator(vovoc->f1());
+               const details::operator_type o2 = operation;
+
+               binary_functor_t f0 = vovoc->f0();
+               binary_functor_t f1 = vovoc->f1();
+               binary_functor_t f2 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+
+               expression_node_ptr result = error_node();
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), v0, v1, c, v2, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o2,f2))
+                  return error_node();
+
+               exprtk_debug(("((v0 o0 v1) o1 c) o2 v2\n"));
+
+               return node_type::allocate(*(expr_gen.node_allocator_), v0, v1, c, v2, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "((t" << expr_gen.to_str(o0)
+                         << "t)"  << expr_gen.to_str(o1)
+                         << "t)"  << expr_gen.to_str(o2)
+                         << "t";
+            }
+         };
+
+         struct synthesize_vocovov_expression3
+         {
+            typedef typename vocovov_t::type3 node_type;
+            typedef typename vocovov_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // ((v0 o0 c) o1 v1) o2 v2
+               typedef typename synthesize_vocov_expression0::node_type lcl_vocov_t;
+
+               const lcl_vocov_t* vocov = static_cast<const lcl_vocov_t*>(branch[0]);
+               const Type& v0 = vocov->t0();
+               const Type   c = vocov->t1();
+               const Type& v1 = vocov->t2();
+               const Type& v2 = static_cast<details::variable_node<Type>*>(branch[1])->ref();
+               const details::operator_type o0 = expr_gen.get_operator(vocov->f0());
+               const details::operator_type o1 = expr_gen.get_operator(vocov->f1());
+               const details::operator_type o2 = operation;
+
+               binary_functor_t f0 = vocov->f0();
+               binary_functor_t f1 = vocov->f1();
+               binary_functor_t f2 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+
+               expression_node_ptr result = error_node();
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), v0, c, v1, v2, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o2,f2))
+                  return error_node();
+
+               exprtk_debug(("((v0 o0 c) o1 v1) o2 v2\n"));
+
+               return node_type::allocate(*(expr_gen.node_allocator_), v0, c, v1, v2, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "((t" << expr_gen.to_str(o0)
+                         << "t)"  << expr_gen.to_str(o1)
+                         << "t)"  << expr_gen.to_str(o2)
+                         << "t";
+            }
+         };
+
+         struct synthesize_covovov_expression3
+         {
+            typedef typename covovov_t::type3 node_type;
+            typedef typename covovov_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // ((c o0 v0) o1 v1) o2 v2
+               typedef typename synthesize_covov_expression0::node_type lcl_covov_t;
+
+               const lcl_covov_t* covov = static_cast<const lcl_covov_t*>(branch[0]);
+               const Type   c = covov->t0();
+               const Type& v0 = covov->t1();
+               const Type& v1 = covov->t2();
+               const Type& v2 = static_cast<details::variable_node<Type>*>(branch[1])->ref();
+               const details::operator_type o0 = expr_gen.get_operator(covov->f0());
+               const details::operator_type o1 = expr_gen.get_operator(covov->f1());
+               const details::operator_type o2 = operation;
+
+               binary_functor_t f0 = covov->f0();
+               binary_functor_t f1 = covov->f1();
+               binary_functor_t f2 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+
+               expression_node_ptr result = error_node();
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), c, v0, v1, v2, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o2,f2))
+                  return error_node();
+
+               exprtk_debug(("((c o0 v0) o1 v1) o2 v2\n"));
+
+               return node_type::allocate(*(expr_gen.node_allocator_), c, v0, v1, v2, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "((t" << expr_gen.to_str(o0)
+                         << "t)"  << expr_gen.to_str(o1)
+                         << "t)"  << expr_gen.to_str(o2)
+                         << "t";
+            }
+         };
+
+         struct synthesize_covocov_expression3
+         {
+            typedef typename covocov_t::type3 node_type;
+            typedef typename covocov_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // ((c0 o0 v0) o1 c1) o2 v1
+               typedef typename synthesize_covoc_expression0::node_type lcl_covoc_t;
+
+               const lcl_covoc_t* covoc = static_cast<const lcl_covoc_t*>(branch[0]);
+               const Type  c0 = covoc->t0();
+               const Type& v0 = covoc->t1();
+               const Type  c1 = covoc->t2();
+               const Type& v1 = static_cast<details::variable_node<Type>*>(branch[1])->ref();
+               const details::operator_type o0 = expr_gen.get_operator(covoc->f0());
+               const details::operator_type o1 = expr_gen.get_operator(covoc->f1());
+               const details::operator_type o2 = operation;
+
+               binary_functor_t f0 = covoc->f0();
+               binary_functor_t f1 = covoc->f1();
+               binary_functor_t f2 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+
+               expression_node_ptr result = error_node();
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), c0, v0, c1, v1, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o2,f2))
+                  return error_node();
+
+               exprtk_debug(("((c0 o0 v0) o1 c1) o2 v1\n"));
+
+               return node_type::allocate(*(expr_gen.node_allocator_), c0, v0, c1, v1, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "((t" << expr_gen.to_str(o0)
+                         << "t)"  << expr_gen.to_str(o1)
+                         << "t)"  << expr_gen.to_str(o2)
+                         << "t";
+            }
+         };
+
+         struct synthesize_vocovoc_expression3
+         {
+            typedef typename vocovoc_t::type3 node_type;
+            typedef typename vocovoc_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // ((v0 o0 c0) o1 v1) o2 c1
+               typedef typename synthesize_vocov_expression0::node_type lcl_vocov_t;
+
+               const lcl_vocov_t* vocov = static_cast<const lcl_vocov_t*>(branch[0]);
+               const Type& v0 = vocov->t0();
+               const Type  c0 = vocov->t1();
+               const Type& v1 = vocov->t2();
+               const Type  c1 = static_cast<details::literal_node<Type>*>(branch[1])->value();
+               const details::operator_type o0 = expr_gen.get_operator(vocov->f0());
+               const details::operator_type o1 = expr_gen.get_operator(vocov->f1());
+               const details::operator_type o2 = operation;
+
+               binary_functor_t f0 = vocov->f0();
+               binary_functor_t f1 = vocov->f1();
+               binary_functor_t f2 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), v0, c0, v1, c1, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o2,f2))
+                  return error_node();
+
+               exprtk_debug(("((v0 o0 c0) o1 v1) o2 c1\n"));
+
+               return node_type::allocate(*(expr_gen.node_allocator_), v0, c0, v1, c1, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "((t" << expr_gen.to_str(o0)
+                         << "t)"  << expr_gen.to_str(o1)
+                         << "t)"  << expr_gen.to_str(o2)
+                         << "t";
+            }
+         };
+
+         struct synthesize_covovoc_expression3
+         {
+            typedef typename covovoc_t::type3 node_type;
+            typedef typename covovoc_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // ((c0 o0 v0) o1 v1) o2 c1
+               typedef typename synthesize_covov_expression0::node_type lcl_covov_t;
+
+               const lcl_covov_t* covov = static_cast<const lcl_covov_t*>(branch[0]);
+               const Type  c0 = covov->t0();
+               const Type& v0 = covov->t1();
+               const Type& v1 = covov->t2();
+               const Type  c1 = static_cast<details::literal_node<Type>*>(branch[1])->value();
+               const details::operator_type o0 = expr_gen.get_operator(covov->f0());
+               const details::operator_type o1 = expr_gen.get_operator(covov->f1());
+               const details::operator_type o2 = operation;
+
+               binary_functor_t f0 = covov->f0();
+               binary_functor_t f1 = covov->f1();
+               binary_functor_t f2 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), c0, v0, v1, c1, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o2,f2))
+                  return error_node();
+
+               exprtk_debug(("((c0 o0 v0) o1 v1) o2 c1\n"));
+
+               return node_type::allocate(*(expr_gen.node_allocator_), c0, v0, v1, c1, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "((t" << expr_gen.to_str(o0)
+                         << "t)"  << expr_gen.to_str(o1)
+                         << "t)"  << expr_gen.to_str(o2)
+                         << "t";
+            }
+         };
+
+         struct synthesize_vococov_expression3
+         {
+            typedef typename vococov_t::type3 node_type;
+            typedef typename vococov_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // ((v0 o0 c0) o1 c1) o2 v1
+               typedef typename synthesize_vococ_expression0::node_type lcl_vococ_t;
+
+               const lcl_vococ_t* vococ = static_cast<const lcl_vococ_t*>(branch[0]);
+               const Type& v0 = vococ->t0();
+               const Type  c0 = vococ->t1();
+               const Type  c1 = vococ->t2();
+               const Type& v1 = static_cast<details::variable_node<Type>*>(branch[1])->ref();
+               const details::operator_type o0 = expr_gen.get_operator(vococ->f0());
+               const details::operator_type o1 = expr_gen.get_operator(vococ->f1());
+               const details::operator_type o2 = operation;
+
+               binary_functor_t f0 = vococ->f0();
+               binary_functor_t f1 = vococ->f1();
+               binary_functor_t f2 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+
+               expression_node_ptr result = error_node();
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), v0, c0, c1, v1, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o2,f2))
+                  return error_node();
+
+               exprtk_debug(("((v0 o0 c0) o1 c1) o2 v1\n"));
+
+               return node_type::allocate(*(expr_gen.node_allocator_), v0, c0, c1, v1, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "((t" << expr_gen.to_str(o0)
+                         << "t)"  << expr_gen.to_str(o1)
+                         << "t)"  << expr_gen.to_str(o2)
+                         << "t";
+            }
+         };
+
+         struct synthesize_vovovov_expression4
+         {
+            typedef typename vovovov_t::type4 node_type;
+            typedef typename vovovov_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // (v0 o0 (v1 o1 v2)) o2 v3
+               typedef typename synthesize_vovov_expression1::node_type lcl_vovov_t;
+
+               const lcl_vovov_t* vovov = static_cast<const lcl_vovov_t*>(branch[0]);
+               const Type& v0 = vovov->t0();
+               const Type& v1 = vovov->t1();
+               const Type& v2 = vovov->t2();
+               const Type& v3 = static_cast<details::variable_node<Type>*>(branch[1])->ref();
+               const details::operator_type o0 = expr_gen.get_operator(vovov->f0());
+               const details::operator_type o1 = expr_gen.get_operator(vovov->f1());
+               const details::operator_type o2 = operation;
+
+               binary_functor_t f0 = vovov->f0();
+               binary_functor_t f1 = vovov->f1();
+               binary_functor_t f2 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+
+               expression_node_ptr result = error_node();
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), v0, v1, v2, v3, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o2,f2))
+                  return error_node();
+
+               exprtk_debug(("(v0 o0 (v1 o1 v2)) o2 v3\n"));
+
+               return node_type::allocate(*(expr_gen.node_allocator_), v0, v1, v2, v3, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "(t" << expr_gen.to_str(o0)
+                         << "(t" << expr_gen.to_str(o1)
+                         << "t)" << expr_gen.to_str(o2)
+                         << "t";
+            }
+         };
+
+         struct synthesize_vovovoc_expression4
+         {
+            typedef typename vovovoc_t::type4 node_type;
+            typedef typename vovovoc_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // ((v0 o0 (v1 o1 v2)) o2 c)
+               typedef typename synthesize_vovov_expression1::node_type lcl_vovov_t;
+
+               const lcl_vovov_t* vovov = static_cast<const lcl_vovov_t*>(branch[0]);
+               const Type& v0 = vovov->t0();
+               const Type& v1 = vovov->t1();
+               const Type& v2 = vovov->t2();
+               const Type   c = static_cast<details::literal_node<Type>*>(branch[1])->value();
+               const details::operator_type o0 = expr_gen.get_operator(vovov->f0());
+               const details::operator_type o1 = expr_gen.get_operator(vovov->f1());
+               const details::operator_type o2 = operation;
+
+               binary_functor_t f0 = vovov->f0();
+               binary_functor_t f1 = vovov->f1();
+               binary_functor_t f2 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), v0, v1, v2, c, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o2,f2))
+                  return error_node();
+
+               exprtk_debug(("((v0 o0 (v1 o1 v2)) o2 c)\n"));
+
+               return node_type::allocate(*(expr_gen.node_allocator_), v0, v1, v2, c, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "(t" << expr_gen.to_str(o0)
+                         << "(t" << expr_gen.to_str(o1)
+                         << "t)" << expr_gen.to_str(o2)
+                         << "t";
+            }
+         };
+
+         struct synthesize_vovocov_expression4
+         {
+            typedef typename vovocov_t::type4 node_type;
+            typedef typename vovocov_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // ((v0 o0 (v1 o1 c)) o2 v1)
+               typedef typename synthesize_vovoc_expression1::node_type lcl_vovoc_t;
+
+               const lcl_vovoc_t* vovoc = static_cast<const lcl_vovoc_t*>(branch[0]);
+               const Type& v0 = vovoc->t0();
+               const Type& v1 = vovoc->t1();
+               const Type   c = vovoc->t2();
+               const Type& v2 = static_cast<details::variable_node<Type>*>(branch[1])->ref();
+               const details::operator_type o0 = expr_gen.get_operator(vovoc->f0());
+               const details::operator_type o1 = expr_gen.get_operator(vovoc->f1());
+               const details::operator_type o2 = operation;
+
+               binary_functor_t f0 = vovoc->f0();
+               binary_functor_t f1 = vovoc->f1();
+               binary_functor_t f2 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+
+               expression_node_ptr result = error_node();
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), v0, v1, c, v2, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o2,f2))
+                  return error_node();
+
+               exprtk_debug(("((v0 o0 (v1 o1 c)) o2 v1)\n"));
+
+               return node_type::allocate(*(expr_gen.node_allocator_), v0, v1, c, v2, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "(t" << expr_gen.to_str(o0)
+                         << "(t" << expr_gen.to_str(o1)
+                         << "t)" << expr_gen.to_str(o2)
+                         << "t";
+            }
+         };
+
+         struct synthesize_vocovov_expression4
+         {
+            typedef typename vocovov_t::type4 node_type;
+            typedef typename vocovov_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // ((v0 o0 (c o1 v1)) o2 v2)
+               typedef typename synthesize_vocov_expression1::node_type lcl_vocov_t;
+
+               const lcl_vocov_t* vocov = static_cast<const lcl_vocov_t*>(branch[0]);
+               const Type& v0 = vocov->t0();
+               const Type   c = vocov->t1();
+               const Type& v1 = vocov->t2();
+               const Type& v2 = static_cast<details::variable_node<Type>*>(branch[1])->ref();
+               const details::operator_type o0 = expr_gen.get_operator(vocov->f0());
+               const details::operator_type o1 = expr_gen.get_operator(vocov->f1());
+               const details::operator_type o2 = operation;
+
+               binary_functor_t f0 = vocov->f0();
+               binary_functor_t f1 = vocov->f1();
+               binary_functor_t f2 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+               expression_node_ptr result = error_node();
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), v0, c, v1, v2, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o2,f2))
+                  return error_node();
+
+               exprtk_debug(("((v0 o0 (c o1 v1)) o2 v2)\n"));
+
+               return node_type::allocate(*(expr_gen.node_allocator_), v0, c, v1, v2, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "(t" << expr_gen.to_str(o0)
+                         << "(t" << expr_gen.to_str(o1)
+                         << "t)" << expr_gen.to_str(o2)
+                         << "t";
+            }
+         };
+
+         struct synthesize_covovov_expression4
+         {
+            typedef typename covovov_t::type4 node_type;
+            typedef typename covovov_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // ((c o0 (v0 o1 v1)) o2 v2)
+               typedef typename synthesize_covov_expression1::node_type lcl_covov_t;
+
+               const lcl_covov_t* covov = static_cast<const lcl_covov_t*>(branch[0]);
+               const Type   c = covov->t0();
+               const Type& v0 = covov->t1();
+               const Type& v1 = covov->t2();
+               const Type& v2 = static_cast<details::variable_node<Type>*>(branch[1])->ref();
+               const details::operator_type o0 = expr_gen.get_operator(covov->f0());
+               const details::operator_type o1 = expr_gen.get_operator(covov->f1());
+               const details::operator_type o2 = operation;
+
+               binary_functor_t f0 = covov->f0();
+               binary_functor_t f1 = covov->f1();
+               binary_functor_t f2 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+
+               expression_node_ptr result = error_node();
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), c, v0, v1, v2, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o2,f2))
+                  return error_node();
+
+               exprtk_debug(("((c o0 (v0 o1 v1)) o2 v2)\n"));
+
+               return node_type::allocate(*(expr_gen.node_allocator_), c, v0, v1, v2, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "(t" << expr_gen.to_str(o0)
+                         << "(t" << expr_gen.to_str(o1)
+                         << "t)" << expr_gen.to_str(o2)
+                         << "t";
+            }
+         };
+
+         struct synthesize_covocov_expression4
+         {
+            typedef typename covocov_t::type4 node_type;
+            typedef typename covocov_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // ((c0 o0 (v0 o1 c1)) o2 v1)
+               typedef typename synthesize_covoc_expression1::node_type lcl_covoc_t;
+
+               const lcl_covoc_t* covoc = static_cast<const lcl_covoc_t*>(branch[0]);
+               const Type  c0 = covoc->t0();
+               const Type& v0 = covoc->t1();
+               const Type  c1 = covoc->t2();
+               const Type& v1 = static_cast<details::variable_node<Type>*>(branch[1])->ref();
+               const details::operator_type o0 = expr_gen.get_operator(covoc->f0());
+               const details::operator_type o1 = expr_gen.get_operator(covoc->f1());
+               const details::operator_type o2 = operation;
+
+               binary_functor_t f0 = covoc->f0();
+               binary_functor_t f1 = covoc->f1();
+               binary_functor_t f2 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+
+               expression_node_ptr result = error_node();
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), c0, v0, c1, v1, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o2,f2))
+                  return error_node();
+
+               exprtk_debug(("((c0 o0 (v0 o1 c1)) o2 v1)\n"));
+
+               return node_type::allocate(*(expr_gen.node_allocator_), c0, v0, c1, v1, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "(t" << expr_gen.to_str(o0)
+                         << "(t" << expr_gen.to_str(o1)
+                         << "t)" << expr_gen.to_str(o2)
+                         << "t";
+            }
+         };
+
+         struct synthesize_vocovoc_expression4
+         {
+            typedef typename vocovoc_t::type4 node_type;
+            typedef typename vocovoc_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // ((v0 o0 (c0 o1 v1)) o2 c1)
+               typedef typename synthesize_vocov_expression1::node_type lcl_vocov_t;
+
+               const lcl_vocov_t* vocov = static_cast<const lcl_vocov_t*>(branch[0]);
+               const Type& v0 = vocov->t0();
+               const Type  c0 = vocov->t1();
+               const Type& v1 = vocov->t2();
+               const Type  c1 = static_cast<details::literal_node<Type>*>(branch[1])->value();
+               const details::operator_type o0 = expr_gen.get_operator(vocov->f0());
+               const details::operator_type o1 = expr_gen.get_operator(vocov->f1());
+               const details::operator_type o2 = operation;
+
+               binary_functor_t f0 = vocov->f0();
+               binary_functor_t f1 = vocov->f1();
+               binary_functor_t f2 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), v0, c0, v1, c1, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o2,f2))
+                  return error_node();
+
+               exprtk_debug(("((v0 o0 (c0 o1 v1)) o2 c1)\n"));
+
+               return node_type::allocate(*(expr_gen.node_allocator_), v0, c0, v1, c1, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "(t" << expr_gen.to_str(o0)
+                         << "(t" << expr_gen.to_str(o1)
+                         << "t)" << expr_gen.to_str(o2)
+                         << "t";
+            }
+         };
+
+         struct synthesize_covovoc_expression4
+         {
+            typedef typename covovoc_t::type4 node_type;
+            typedef typename covovoc_t::sf4_type sf4_type;
+            typedef typename node_type::T0 T0;
+            typedef typename node_type::T1 T1;
+            typedef typename node_type::T2 T2;
+            typedef typename node_type::T3 T3;
+
+            static inline expression_node_ptr process(expression_generator<Type>& expr_gen,
+                                                      const details::operator_type& operation,
+                                                      expression_node_ptr (&branch)[2])
+            {
+               // ((c0 o0 (v0 o1 v1)) o2 c1)
+               typedef typename synthesize_covov_expression1::node_type lcl_covov_t;
+
+               const lcl_covov_t* covov = static_cast<const lcl_covov_t*>(branch[0]);
+               const Type  c0 = covov->t0();
+               const Type& v0 = covov->t1();
+               const Type& v1 = covov->t2();
+               const Type  c1 = static_cast<details::literal_node<Type>*>(branch[1])->value();
+               const details::operator_type o0 = expr_gen.get_operator(covov->f0());
+               const details::operator_type o1 = expr_gen.get_operator(covov->f1());
+               const details::operator_type o2 = operation;
+
+               binary_functor_t f0 = covov->f0();
+               binary_functor_t f1 = covov->f1();
+               binary_functor_t f2 = reinterpret_cast<binary_functor_t>(0);
+
+               details::free_node(*(expr_gen.node_allocator_),branch[0]);
+               details::free_node(*(expr_gen.node_allocator_),branch[1]);
+
+               expression_node_ptr result = error_node();
+
+               const bool synthesis_result =
+                  synthesize_sf4ext_expression::template compile<T0, T1, T2, T3>
+                     (expr_gen, id(expr_gen, o0, o1, o2), c0, v0, v1, c1, result);
+
+               if (synthesis_result)
+                  return result;
+               else if (!expr_gen.valid_operator(o2,f2))
+                  return error_node();
+
+               exprtk_debug(("((c0 o0 (v0 o1 v1)) o2 c1)\n"));
+
+               return node_type::allocate(*(expr_gen.node_allocator_), c0, v0, v1, c1, f0, f1, f2);
+            }
+
+            static inline std::string id(expression_generator<Type>& expr_gen,
+                                         const details::operator_type o0,
+                                         const details::operator_type o1,
+                                         const details::operator_type o2)
+            {
+               return details::build_string()
+                         << "(t" << expr_gen.to_str(o0)
+                         << "(t" << expr_gen.to_str(o1)
+                         << "t)" << expr_gen.to_str(o2)
+                         << "t";
+            }
+         };
+
+         struct synthesize_vococov_expression4
+         {
+            typedef typename vococov_t::type4 node_type;
+            static inline expression_node_ptr process(expression_generator<Type>&, const details::operator_type&, expression_node_ptr (&)[2])
+            {
+               // ((v0 o0 (c0 o1 c1)) o2 v1) - Not possible
+               exprtk_debug(("((v0 o0 (c0 o1 c1)) o2 v1) - Not possible\n"));
+               return error_node();
+            }
+
+            static inline std::string id(expression_generator<Type>&,
+                                         const details::operator_type, const details::operator_type, const details::operator_type)
+            {
+               return "INVALID";
+            }
+         };
+         #endif
+
+         inline expression_node_ptr synthesize_uvouv_expression(const details::operator_type& operation, expression_node_ptr (&branch)[2])
+         {
+            // Definition: uv o uv
+            details::operator_type o0 = static_cast<details::uv_base_node<Type>*>(branch[0])->operation();
+            details::operator_type o1 = static_cast<details::uv_base_node<Type>*>(branch[1])->operation();
+            const Type& v0 = static_cast<details::uv_base_node<Type>*>(branch[0])->v();
+            const Type& v1 = static_cast<details::uv_base_node<Type>*>(branch[1])->v();
+            unary_functor_t u0 = reinterpret_cast<unary_functor_t> (0);
+            unary_functor_t u1 = reinterpret_cast<unary_functor_t> (0);
+            binary_functor_t f = reinterpret_cast<binary_functor_t>(0);
+
+            if (!valid_operator(o0,u0))
+               return error_node();
+            else if (!valid_operator(o1,u1))
+               return error_node();
+            else if (!valid_operator(operation,f))
+               return error_node();
+
+            expression_node_ptr result = error_node();
+
+            if (
+                 (details::e_neg == o0) &&
+                 (details::e_neg == o1)
+               )
+            {
+               switch (operation)
+               {
+                  // (-v0 + -v1) --> -(v0 + v1)
+                  case details::e_add : result = (*this)(details::e_neg,
+                                                    node_allocator_->
+                                                       allocate_rr<typename details::
+                                                          vov_node<Type,details::add_op<Type> > >(v0, v1));
+                                        exprtk_debug(("(-v0 + -v1) --> -(v0 + v1)\n"));
+                                        break;
+
+                  // (-v0 - -v1) --> (v1 - v0)
+                  case details::e_sub : result = node_allocator_->
+                                                    allocate_rr<typename details::
+                                                       vov_node<Type,details::sub_op<Type> > >(v1, v0);
+                                        exprtk_debug(("(-v0 - -v1) --> (v1 - v0)\n"));
+                                        break;
+
+                  // (-v0 * -v1) --> (v0 * v1)
+                  case details::e_mul : result = node_allocator_->
+                                                    allocate_rr<typename details::
+                                                       vov_node<Type,details::mul_op<Type> > >(v0, v1);
+                                        exprtk_debug(("(-v0 * -v1) --> (v0 * v1)\n"));
+                                        break;
+
+                  // (-v0 / -v1) --> (v0 / v1)
+                  case details::e_div : result = node_allocator_->
+                                                    allocate_rr<typename details::
+                                                       vov_node<Type,details::div_op<Type> > >(v0, v1);
+                                        exprtk_debug(("(-v0 / -v1) --> (v0 / v1)\n"));
+                                        break;
+
+                  default             : break;
+               }
+            }
+
+            if (0 == result)
+            {
+               result = node_allocator_->
+                            allocate_rrrrr<typename details::uvouv_node<Type> >(v0, v1, u0, u1, f);
+            }
+
+            details::free_all_nodes(*node_allocator_,branch);
+            return result;
+         }
+
+         #undef basic_opr_switch_statements
+         #undef extended_opr_switch_statements
+         #undef unary_opr_switch_statements
+
+         #ifndef exprtk_disable_string_capabilities
+
+         #define string_opr_switch_statements          \
+         case_stmt(details::  e_lt ,details::   lt_op) \
+         case_stmt(details:: e_lte ,details::  lte_op) \
+         case_stmt(details::  e_gt ,details::   gt_op) \
+         case_stmt(details:: e_gte ,details::  gte_op) \
+         case_stmt(details::  e_eq ,details::   eq_op) \
+         case_stmt(details::  e_ne ,details::   ne_op) \
+         case_stmt(details::e_in   ,details::   in_op) \
+         case_stmt(details::e_like ,details:: like_op) \
+         case_stmt(details::e_ilike,details::ilike_op) \
+
+         template <typename T0, typename T1>
+         inline expression_node_ptr synthesize_str_xrox_expression_impl(const details::operator_type& opr,
+                                                                        T0 s0, T1 s1,
+                                                                        range_t rp0)
+         {
+            switch (opr)
+            {
+               #define case_stmt(op0,op1)                                                                       \
+               case op0 : return node_allocator_->                                                              \
+                             allocate_ttt<typename details::str_xrox_node<Type,T0,T1,range_t,op1<Type> >,T0,T1> \
+                                (s0, s1, rp0);                                                                  \
+
+               string_opr_switch_statements
+               #undef case_stmt
+               default : return error_node();
+            }
+         }
+
+         template <typename T0, typename T1>
+         inline expression_node_ptr synthesize_str_xoxr_expression_impl(const details::operator_type& opr,
+                                                                        T0 s0, T1 s1,
+                                                                        range_t rp1)
+         {
+            switch (opr)
+            {
+               #define case_stmt(op0,op1)                                                                       \
+               case op0 : return node_allocator_->                                                              \
+                             allocate_ttt<typename details::str_xoxr_node<Type,T0,T1,range_t,op1<Type> >,T0,T1> \
+                                (s0, s1, rp1);                                                                  \
+
+               string_opr_switch_statements
+               #undef case_stmt
+               default : return error_node();
+            }
+         }
+
+         template <typename T0, typename T1>
+         inline expression_node_ptr synthesize_str_xroxr_expression_impl(const details::operator_type& opr,
+                                                                         T0 s0, T1 s1,
+                                                                         range_t rp0, range_t rp1)
+         {
+            switch (opr)
+            {
+               #define case_stmt(op0,op1)                                                                         \
+               case op0 : return node_allocator_->                                                                \
+                             allocate_tttt<typename details::str_xroxr_node<Type,T0,T1,range_t,op1<Type> >,T0,T1> \
+                                (s0, s1, rp0, rp1);                                                               \
+
+               string_opr_switch_statements
+               #undef case_stmt
+               default : return error_node();
+            }
+         }
+
+         template <typename T0, typename T1>
+         inline expression_node_ptr synthesize_sos_expression_impl(const details::operator_type& opr, T0 s0, T1 s1)
+         {
+            switch (opr)
+            {
+               #define case_stmt(op0,op1)                                                                  \
+               case op0 : return node_allocator_->                                                         \
+                             allocate_tt<typename details::sos_node<Type,T0,T1,op1<Type> >,T0,T1>(s0, s1); \
+
+               string_opr_switch_statements
+               #undef case_stmt
+               default : return error_node();
+            }
+         }
+
+         inline expression_node_ptr synthesize_sos_expression(const details::operator_type& opr, expression_node_ptr (&branch)[2])
+         {
+            std::string& s0 = static_cast<details::stringvar_node<Type>*>(branch[0])->ref();
+            std::string& s1 = static_cast<details::stringvar_node<Type>*>(branch[1])->ref();
+
+            return synthesize_sos_expression_impl<std::string&,std::string&>(opr, s0, s1);
+         }
+
+         inline expression_node_ptr synthesize_sros_expression(const details::operator_type& opr, expression_node_ptr (&branch)[2])
+         {
+            std::string&  s0 = static_cast<details::string_range_node<Type>*>(branch[0])->ref  ();
+            std::string&  s1 = static_cast<details::stringvar_node<Type>*>   (branch[1])->ref  ();
+            range_t      rp0 = static_cast<details::string_range_node<Type>*>(branch[0])->range();
+
+            static_cast<details::string_range_node<Type>*>(branch[0])->range_ref().clear();
+
+            free_node(*node_allocator_,branch[0]);
+
+            return synthesize_str_xrox_expression_impl<std::string&,std::string&>(opr, s0, s1, rp0);
+         }
+
+         inline expression_node_ptr synthesize_sosr_expression(const details::operator_type& opr, expression_node_ptr (&branch)[2])
+         {
+            std::string&  s0 = static_cast<details::stringvar_node<Type>*>   (branch[0])->ref  ();
+            std::string&  s1 = static_cast<details::string_range_node<Type>*>(branch[1])->ref  ();
+            range_t      rp1 = static_cast<details::string_range_node<Type>*>(branch[1])->range();
+
+            static_cast<details::string_range_node<Type>*>(branch[1])->range_ref().clear();
+
+            free_node(*node_allocator_,branch[1]);
+
+            return synthesize_str_xoxr_expression_impl<std::string&,std::string&>(opr, s0, s1, rp1);
+         }
+
+         inline expression_node_ptr synthesize_socsr_expression(const details::operator_type& opr, expression_node_ptr (&branch)[2])
+         {
+            std::string&  s0 = static_cast<details::stringvar_node<Type>*>         (branch[0])->ref  ();
+            std::string   s1 = static_cast<details::const_string_range_node<Type>*>(branch[1])->str  ();
+            range_t      rp1 = static_cast<details::const_string_range_node<Type>*>(branch[1])->range();
+
+            static_cast<details::const_string_range_node<Type>*>(branch[1])->range_ref().clear();
+
+            free_node(*node_allocator_,branch[1]);
+
+            return synthesize_str_xoxr_expression_impl<std::string&, const std::string>(opr, s0, s1, rp1);
+         }
+
+         inline expression_node_ptr synthesize_srosr_expression(const details::operator_type& opr, expression_node_ptr (&branch)[2])
+         {
+            std::string&  s0 = static_cast<details::string_range_node<Type>*>(branch[0])->ref  ();
+            std::string&  s1 = static_cast<details::string_range_node<Type>*>(branch[1])->ref  ();
+            range_t      rp0 = static_cast<details::string_range_node<Type>*>(branch[0])->range();
+            range_t      rp1 = static_cast<details::string_range_node<Type>*>(branch[1])->range();
+
+            static_cast<details::string_range_node<Type>*>(branch[0])->range_ref().clear();
+            static_cast<details::string_range_node<Type>*>(branch[1])->range_ref().clear();
+
+            details::free_node(*node_allocator_,branch[0]);
+            details::free_node(*node_allocator_,branch[1]);
+
+            return synthesize_str_xroxr_expression_impl<std::string&,std::string&>(opr, s0, s1, rp0, rp1);
+         }
+
+         inline expression_node_ptr synthesize_socs_expression(const details::operator_type& opr, expression_node_ptr (&branch)[2])
+         {
+            std::string& s0 = static_cast<     details::stringvar_node<Type>*>(branch[0])->ref();
+            std::string  s1 = static_cast<details::string_literal_node<Type>*>(branch[1])->str();
+
+            details::free_node(*node_allocator_,branch[1]);
+
+            return synthesize_sos_expression_impl<std::string&, const std::string>(opr, s0, s1);
+         }
+
+         inline expression_node_ptr synthesize_csos_expression(const details::operator_type& opr, expression_node_ptr (&branch)[2])
+         {
+            std::string  s0 = static_cast<details::string_literal_node<Type>*>(branch[0])->str();
+            std::string& s1 = static_cast<     details::stringvar_node<Type>*>(branch[1])->ref();
+
+            details::free_node(*node_allocator_,branch[0]);
+
+            return synthesize_sos_expression_impl<const std::string,std::string&>(opr, s0, s1);
+         }
+
+         inline expression_node_ptr synthesize_csosr_expression(const details::operator_type& opr, expression_node_ptr (&branch)[2])
+         {
+            std::string   s0 = static_cast<details::string_literal_node<Type>*>(branch[0])->str  ();
+            std::string&  s1 = static_cast<details::string_range_node<Type>*>  (branch[1])->ref  ();
+            range_t      rp1 = static_cast<details::string_range_node<Type>*>  (branch[1])->range();
+
+            static_cast<details::string_range_node<Type>*>(branch[1])->range_ref().clear();
+
+            details::free_node(*node_allocator_,branch[0]);
+            details::free_node(*node_allocator_,branch[1]);
+
+            return synthesize_str_xoxr_expression_impl<const std::string,std::string&>(opr, s0, s1, rp1);
+         }
+
+         inline expression_node_ptr synthesize_srocs_expression(const details::operator_type& opr, expression_node_ptr (&branch)[2])
+         {
+            std::string&  s0 = static_cast<details::string_range_node<Type>*>  (branch[0])->ref  ();
+            std::string   s1 = static_cast<details::string_literal_node<Type>*>(branch[1])->str  ();
+            range_t      rp0 = static_cast<details::string_range_node<Type>*>  (branch[0])->range();
+
+            static_cast<details::string_range_node<Type>*>(branch[0])->range_ref().clear();
+
+            details::free_node(*node_allocator_,branch[0]);
+            details::free_node(*node_allocator_,branch[1]);
+
+            return synthesize_str_xrox_expression_impl<std::string&, const std::string>(opr, s0, s1, rp0);
+         }
+
+         inline expression_node_ptr synthesize_srocsr_expression(const details::operator_type& opr, expression_node_ptr (&branch)[2])
+         {
+            std::string&  s0 = static_cast<details::string_range_node<Type>*>      (branch[0])->ref  ();
+            std::string   s1 = static_cast<details::const_string_range_node<Type>*>(branch[1])->str  ();
+            range_t      rp0 = static_cast<details::string_range_node<Type>*>      (branch[0])->range();
+            range_t      rp1 = static_cast<details::const_string_range_node<Type>*>(branch[1])->range();
+
+            static_cast<details::string_range_node<Type>*>      (branch[0])->range_ref().clear();
+            static_cast<details::const_string_range_node<Type>*>(branch[1])->range_ref().clear();
+
+            details::free_node(*node_allocator_,branch[0]);
+            details::free_node(*node_allocator_,branch[1]);
+
+            return synthesize_str_xroxr_expression_impl<std::string&, const std::string>(opr, s0, s1, rp0, rp1);
+         }
+
+         inline expression_node_ptr synthesize_csocs_expression(const details::operator_type& opr, expression_node_ptr (&branch)[2])
+         {
+            const std::string s0 = static_cast<details::string_literal_node<Type>*>(branch[0])->str();
+            const std::string s1 = static_cast<details::string_literal_node<Type>*>(branch[1])->str();
+
+            expression_node_ptr result = error_node();
+
+            if (details::e_add == opr)
+               result = node_allocator_->allocate_c<details::string_literal_node<Type> >(s0 + s1);
+            else if (details::e_in == opr)
+               result = node_allocator_->allocate_c<details::literal_node<Type> >(details::in_op   <Type>::process(s0,s1));
+            else if (details::e_like == opr)
+               result = node_allocator_->allocate_c<details::literal_node<Type> >(details::like_op <Type>::process(s0,s1));
+            else if (details::e_ilike == opr)
+               result = node_allocator_->allocate_c<details::literal_node<Type> >(details::ilike_op<Type>::process(s0,s1));
+            else
+            {
+               expression_node_ptr temp = synthesize_sos_expression_impl<const std::string, const std::string>(opr, s0, s1);
+
+               const Type v = temp->value();
+
+               details::free_node(*node_allocator_,temp);
+
+               result = node_allocator_->allocate<literal_node_t>(v);
+            }
+
+            details::free_all_nodes(*node_allocator_,branch);
+
+            return result;
+         }
+
+         inline expression_node_ptr synthesize_csocsr_expression(const details::operator_type& opr, expression_node_ptr (&branch)[2])
+         {
+            const std::string s0 = static_cast<details::string_literal_node<Type>*>    (branch[0])->str  ();
+                  std::string s1 = static_cast<details::const_string_range_node<Type>*>(branch[1])->str  ();
+            range_t          rp1 = static_cast<details::const_string_range_node<Type>*>(branch[1])->range();
+
+            static_cast<details::const_string_range_node<Type>*>(branch[1])->range_ref().clear();
+
+            free_node(*node_allocator_,branch[0]);
+            free_node(*node_allocator_,branch[1]);
+
+            return synthesize_str_xoxr_expression_impl<const std::string, const std::string>(opr, s0, s1, rp1);
+         }
+
+         inline expression_node_ptr synthesize_csros_expression(const details::operator_type& opr, expression_node_ptr (&branch)[2])
+         {
+            std::string   s0 = static_cast<details::const_string_range_node<Type>*>(branch[0])->str  ();
+            std::string&  s1 = static_cast<details::stringvar_node<Type>*>         (branch[1])->ref  ();
+            range_t      rp0 = static_cast<details::const_string_range_node<Type>*>(branch[0])->range();
+
+            static_cast<details::const_string_range_node<Type>*>(branch[0])->range_ref().clear();
+
+            free_node(*node_allocator_,branch[0]);
+
+            return synthesize_str_xrox_expression_impl<const std::string,std::string&>(opr, s0, s1, rp0);
+         }
+
+         inline expression_node_ptr synthesize_csrosr_expression(const details::operator_type& opr, expression_node_ptr (&branch)[2])
+         {
+            const std::string  s0 = static_cast<details::const_string_range_node<Type>*>(branch[0])->str  ();
+                  std::string& s1 = static_cast<details::string_range_node<Type>*>      (branch[1])->ref  ();
+            const range_t     rp0 = static_cast<details::const_string_range_node<Type>*>(branch[0])->range();
+            const range_t     rp1 = static_cast<details::string_range_node<Type>*>      (branch[1])->range();
+
+            static_cast<details::const_string_range_node<Type>*>(branch[0])->range_ref().clear();
+            static_cast<details::string_range_node<Type>*>      (branch[1])->range_ref().clear();
+
+            free_node(*node_allocator_,branch[0]);
+            free_node(*node_allocator_,branch[1]);
+
+            return synthesize_str_xroxr_expression_impl<const std::string,std::string&>(opr, s0, s1, rp0, rp1);
+         }
+
+         inline expression_node_ptr synthesize_csrocs_expression(const details::operator_type& opr, expression_node_ptr (&branch)[2])
+         {
+            const std::string s0 = static_cast<details::const_string_range_node<Type>*>(branch[0])->str  ();
+            const std::string s1 = static_cast<details::string_literal_node<Type>*>    (branch[1])->str  ();
+            const range_t    rp0 = static_cast<details::const_string_range_node<Type>*>(branch[0])->range();
+
+            static_cast<details::const_string_range_node<Type>*>(branch[0])->range_ref().clear();
+
+            details::free_all_nodes(*node_allocator_,branch);
+
+            return synthesize_str_xrox_expression_impl<const std::string,std::string>(opr, s0, s1, rp0);
+         }
+
+         inline expression_node_ptr synthesize_csrocsr_expression(const details::operator_type& opr, expression_node_ptr (&branch)[2])
+         {
+            const std::string s0 = static_cast<details::const_string_range_node<Type>*>(branch[0])->str  ();
+            const std::string s1 = static_cast<details::const_string_range_node<Type>*>(branch[1])->str  ();
+            const range_t    rp0 = static_cast<details::const_string_range_node<Type>*>(branch[0])->range();
+            const range_t    rp1 = static_cast<details::const_string_range_node<Type>*>(branch[1])->range();
+
+            static_cast<details::const_string_range_node<Type>*>(branch[0])->range_ref().clear();
+            static_cast<details::const_string_range_node<Type>*>(branch[1])->range_ref().clear();
+
+            details::free_all_nodes(*node_allocator_,branch);
+
+            return synthesize_str_xroxr_expression_impl<const std::string, const std::string>(opr, s0, s1, rp0, rp1);
+         }
+
+         inline expression_node_ptr synthesize_strogen_expression(const details::operator_type& opr, expression_node_ptr (&branch)[2])
+         {
+            switch (opr)
+            {
+               #define case_stmt(op0,op1)                                                       \
+               case op0 : return node_allocator_->                                              \
+                             allocate_ttt<typename details::str_sogens_node<Type,op1<Type> > >  \
+                                (opr, branch[0], branch[1]);                                    \
+
+               string_opr_switch_statements
+               #undef case_stmt
+               default : return error_node();
+            }
+         }
+         #endif
+
+         #ifndef exprtk_disable_string_capabilities
+         inline expression_node_ptr synthesize_string_expression(const details::operator_type& opr, expression_node_ptr (&branch)[2])
+         {
+            if ((0 == branch[0]) || (0 == branch[1]))
+            {
+               details::free_all_nodes(*node_allocator_,branch);
+
+               return error_node();
+            }
+
+            const bool b0_is_s   = details::is_string_node            (branch[0]);
+            const bool b0_is_cs  = details::is_const_string_node      (branch[0]);
+            const bool b0_is_sr  = details::is_string_range_node      (branch[0]);
+            const bool b0_is_csr = details::is_const_string_range_node(branch[0]);
+
+            const bool b1_is_s   = details::is_string_node            (branch[1]);
+            const bool b1_is_cs  = details::is_const_string_node      (branch[1]);
+            const bool b1_is_sr  = details::is_string_range_node      (branch[1]);
+            const bool b1_is_csr = details::is_const_string_range_node(branch[1]);
+
+            const bool b0_is_gen = details::is_string_assignment_node (branch[0]) ||
+                                   details::is_genricstring_range_node(branch[0]) ||
+                                   details::is_string_concat_node     (branch[0]) ||
+                                   details::is_string_function_node   (branch[0]) ||
+                                   details::is_string_condition_node  (branch[0]) ||
+                                   details::is_string_ccondition_node (branch[0]) ||
+                                   details::is_string_vararg_node     (branch[0]) ;
+
+            const bool b1_is_gen = details::is_string_assignment_node (branch[1]) ||
+                                   details::is_genricstring_range_node(branch[1]) ||
+                                   details::is_string_concat_node     (branch[1]) ||
+                                   details::is_string_function_node   (branch[1]) ||
+                                   details::is_string_condition_node  (branch[1]) ||
+                                   details::is_string_ccondition_node (branch[1]) ||
+                                   details::is_string_vararg_node     (branch[1]) ;
+
+            if (details::e_add == opr)
+            {
+               if (!b0_is_cs || !b1_is_cs)
+               {
+                  return synthesize_expression<string_concat_node_t,2>(opr,branch);
+               }
+            }
+
+            if (b0_is_gen || b1_is_gen)
+            {
+               return synthesize_strogen_expression(opr,branch);
+            }
+            else if (b0_is_s)
+            {
+                    if (b1_is_s  ) return synthesize_sos_expression   (opr,branch);
+               else if (b1_is_cs ) return synthesize_socs_expression  (opr,branch);
+               else if (b1_is_sr ) return synthesize_sosr_expression  (opr,branch);
+               else if (b1_is_csr) return synthesize_socsr_expression (opr,branch);
+            }
+            else if (b0_is_cs)
+            {
+                    if (b1_is_s  ) return synthesize_csos_expression  (opr,branch);
+               else if (b1_is_cs ) return synthesize_csocs_expression (opr,branch);
+               else if (b1_is_sr ) return synthesize_csosr_expression (opr,branch);
+               else if (b1_is_csr) return synthesize_csocsr_expression(opr,branch);
+            }
+            else if (b0_is_sr)
+            {
+                    if (b1_is_s  ) return synthesize_sros_expression  (opr,branch);
+               else if (b1_is_sr ) return synthesize_srosr_expression (opr,branch);
+               else if (b1_is_cs ) return synthesize_srocs_expression (opr,branch);
+               else if (b1_is_csr) return synthesize_srocsr_expression(opr,branch);
+            }
+            else if (b0_is_csr)
+            {
+                    if (b1_is_s  ) return synthesize_csros_expression  (opr,branch);
+               else if (b1_is_sr ) return synthesize_csrosr_expression (opr,branch);
+               else if (b1_is_cs ) return synthesize_csrocs_expression (opr,branch);
+               else if (b1_is_csr) return synthesize_csrocsr_expression(opr,branch);
+            }
+
+            return error_node();
+         }
+         #else
+         inline expression_node_ptr synthesize_string_expression(const details::operator_type&, expression_node_ptr (&branch)[2])
+         {
+            details::free_all_nodes(*node_allocator_,branch);
+            return error_node();
+         }
+         #endif
+
+         #ifndef exprtk_disable_string_capabilities
+         inline expression_node_ptr synthesize_string_expression(const details::operator_type& opr, expression_node_ptr (&branch)[3])
+         {
+            if (details::e_inrange != opr)
+               return error_node();
+            else if ((0 == branch[0]) || (0 == branch[1]) || (0 == branch[2]))
+            {
+               details::free_all_nodes(*node_allocator_,branch);
+
+               return error_node();
+            }
+            else if (
+                      details::is_const_string_node(branch[0]) &&
+                      details::is_const_string_node(branch[1]) &&
+                      details::is_const_string_node(branch[2])
+                    )
+            {
+               const std::string s0 = static_cast<details::string_literal_node<Type>*>(branch[0])->str();
+               const std::string s1 = static_cast<details::string_literal_node<Type>*>(branch[1])->str();
+               const std::string s2 = static_cast<details::string_literal_node<Type>*>(branch[2])->str();
+
+               const Type v = (((s0 <= s1) && (s1 <= s2)) ? Type(1) : Type(0));
+
+               details::free_all_nodes(*node_allocator_,branch);
+
+               return node_allocator_->allocate_c<details::literal_node<Type> >(v);
+            }
+            else if (
+                      details::is_string_node(branch[0]) &&
+                      details::is_string_node(branch[1]) &&
+                      details::is_string_node(branch[2])
+                    )
+            {
+               std::string& s0 = static_cast<details::stringvar_node<Type>*>(branch[0])->ref();
+               std::string& s1 = static_cast<details::stringvar_node<Type>*>(branch[1])->ref();
+               std::string& s2 = static_cast<details::stringvar_node<Type>*>(branch[2])->ref();
+
+               typedef typename details::sosos_node<Type, std::string&, std::string&, std::string&, details::inrange_op<Type> > inrange_t;
+
+               return node_allocator_->allocate_type<inrange_t, std::string&, std::string&, std::string&>(s0, s1, s2);
+            }
+            else if (
+                      details::is_const_string_node(branch[0]) &&
+                            details::is_string_node(branch[1]) &&
+                      details::is_const_string_node(branch[2])
+                    )
+            {
+               std::string  s0 = static_cast<details::string_literal_node<Type>*>(branch[0])->str();
+               std::string& s1 = static_cast<     details::stringvar_node<Type>*>(branch[1])->ref();
+               std::string  s2 = static_cast<details::string_literal_node<Type>*>(branch[2])->str();
+
+               typedef typename details::sosos_node<Type, std::string, std::string&, std::string, details::inrange_op<Type> > inrange_t;
+
+               details::free_node(*node_allocator_,branch[0]);
+               details::free_node(*node_allocator_,branch[2]);
+
+               return node_allocator_->allocate_type<inrange_t, std::string, std::string&, std::string>(s0, s1, s2);
+            }
+            else if (
+                            details::is_string_node(branch[0]) &&
+                      details::is_const_string_node(branch[1]) &&
+                            details::is_string_node(branch[2])
+                    )
+            {
+               std::string&  s0 = static_cast<     details::stringvar_node<Type>*>(branch[0])->ref();
+               std::string   s1 = static_cast<details::string_literal_node<Type>*>(branch[1])->str();
+               std::string&  s2 = static_cast<     details::stringvar_node<Type>*>(branch[2])->ref();
+
+               typedef typename details::sosos_node<Type, std::string&, std::string, std::string&, details::inrange_op<Type> > inrange_t;
+
+               details::free_node(*node_allocator_,branch[1]);
+
+               return node_allocator_->allocate_type<inrange_t, std::string&, std::string, std::string&>(s0, s1, s2);
+            }
+            else if (
+                      details::is_string_node(branch[0]) &&
+                      details::is_string_node(branch[1]) &&
+                      details::is_const_string_node(branch[2])
+                    )
+            {
+               std::string& s0 = static_cast<     details::stringvar_node<Type>*>(branch[0])->ref();
+               std::string& s1 = static_cast<     details::stringvar_node<Type>*>(branch[1])->ref();
+               std::string  s2 = static_cast<details::string_literal_node<Type>*>(branch[2])->str();
+
+               typedef typename details::sosos_node<Type, std::string&, std::string&, std::string, details::inrange_op<Type> > inrange_t;
+
+               details::free_node(*node_allocator_,branch[2]);
+
+               return node_allocator_->allocate_type<inrange_t, std::string&, std::string&, std::string>(s0, s1, s2);
+            }
+            else if (
+                      details::is_const_string_node(branch[0]) &&
+                      details::      is_string_node(branch[1]) &&
+                      details::      is_string_node(branch[2])
+                    )
+            {
+               std::string  s0 = static_cast<details::string_literal_node<Type>*>(branch[0])->str();
+               std::string& s1 = static_cast<     details::stringvar_node<Type>*>(branch[1])->ref();
+               std::string& s2 = static_cast<     details::stringvar_node<Type>*>(branch[2])->ref();
+
+               typedef typename details::sosos_node<Type, std::string, std::string&, std::string&, details::inrange_op<Type> > inrange_t;
+
+               details::free_node(*node_allocator_,branch[0]);
+
+               return node_allocator_->allocate_type<inrange_t, std::string, std::string&, std::string&>(s0, s1, s2);
+            }
+            else
+               return error_node();
+         }
+         #else
+         inline expression_node_ptr synthesize_string_expression(const details::operator_type&, expression_node_ptr (&branch)[3])
+         {
+            details::free_all_nodes(*node_allocator_,branch);
+            return error_node();
+         }
+         #endif
+
+         inline expression_node_ptr synthesize_null_expression(const details::operator_type& operation, expression_node_ptr (&branch)[2])
+         {
+            /*
+             Note: The following are the type promotion rules
+             that relate to operations that include 'null':
+             0. null ==/!=     null --> true false
+             1. null operation null --> null
+             2. x    ==/!=     null --> true/false
+             3. null ==/!=     x    --> true/false
+             4. x   operation  null --> x
+             5. null operation x    --> x
+            */
+
+            typedef typename details::null_eq_node<T> nulleq_node_t;
+
+            const bool b0_null = details::is_null_node(branch[0]);
+            const bool b1_null = details::is_null_node(branch[1]);
+
+            if (b0_null && b1_null)
+            {
+               expression_node_ptr result = error_node();
+
+               if (details::e_eq == operation)
+                  result = node_allocator_->allocate_c<literal_node_t>(T(1));
+               else if (details::e_ne == operation)
+                  result = node_allocator_->allocate_c<literal_node_t>(T(0));
+
+               if (result)
+               {
+                  details::free_node(*node_allocator_,branch[0]);
+                  details::free_node(*node_allocator_,branch[1]);
+
+                  return result;
+               }
+
+               details::free_node(*node_allocator_,branch[1]);
+
+               return branch[0];
+            }
+            else if (details::e_eq == operation)
+            {
+               expression_node_ptr result = node_allocator_->
+                                                allocate_rc<nulleq_node_t>(branch[b0_null ? 0 : 1],true);
+
+               details::free_node(*node_allocator_,branch[b0_null ? 1 : 0]);
+
+               return result;
+            }
+            else if (details::e_ne == operation)
+            {
+               expression_node_ptr result = node_allocator_->
+                                                allocate_rc<nulleq_node_t>(branch[b0_null ? 0 : 1],false);
+
+               details::free_node(*node_allocator_,branch[b0_null ? 1 : 0]);
+
+               return result;
+            }
+            else if (b0_null)
+            {
+               details::free_node(*node_allocator_,branch[0]);
+               branch[0] = branch[1];
+               branch[1] = error_node();
+            }
+            else if (b1_null)
+            {
+               details::free_node(*node_allocator_,branch[1]);
+               branch[1] = error_node();
+            }
+
+            if (
+                 (details::e_add == operation) || (details::e_sub == operation) ||
+                 (details::e_mul == operation) || (details::e_div == operation) ||
+                 (details::e_mod == operation) || (details::e_pow == operation)
+               )
+            {
+               return branch[0];
+            }
+            else if (
+                      (details::e_lt    == operation) || (details::e_lte  == operation) ||
+                      (details::e_gt    == operation) || (details::e_gte  == operation) ||
+                      (details::e_and   == operation) || (details::e_nand == operation) ||
+                      (details::e_or    == operation) || (details::e_nor  == operation) ||
+                      (details::e_xor   == operation) || (details::e_xnor == operation) ||
+                      (details::e_in    == operation) || (details::e_like == operation) ||
+                      (details::e_ilike == operation)
+                    )
+            {
+               return node_allocator_->allocate_c<literal_node_t>(T(0));
+            }
+
+            details::free_node(*node_allocator_,branch[0]);
+
+            return node_allocator_->allocate<details::null_node<Type> >();
+         }
+
+         template <typename NodeType, std::size_t N>
+         inline expression_node_ptr synthesize_expression(const details::operator_type& operation, expression_node_ptr (&branch)[N])
+         {
+            if (
+                 (details::e_in    == operation) ||
+                 (details::e_like  == operation) ||
+                 (details::e_ilike == operation)
+               )
+            {
+               free_all_nodes(*node_allocator_,branch);
+
+               return error_node();
+            }
+            else if (!details::all_nodes_valid<N>(branch))
+            {
+               free_all_nodes(*node_allocator_,branch);
+
+               return error_node();
+            }
+            else if ((details::e_default != operation))
+            {
+               // Attempt simple constant folding optimisation.
+               expression_node_ptr expression_point = node_allocator_->allocate<NodeType>(operation,branch);
+
+               if (is_constant_foldable<N>(branch))
+               {
+                  const Type v = expression_point->value();
+                  details::free_node(*node_allocator_,expression_point);
+
+                  return node_allocator_->allocate<literal_node_t>(v);
+               }
+               else
+                  return expression_point;
+            }
+            else
+               return error_node();
+         }
+
+         template <typename NodeType, std::size_t N>
+         inline expression_node_ptr synthesize_expression(F* f, expression_node_ptr (&branch)[N])
+         {
+            if (!details::all_nodes_valid<N>(branch))
+            {
+               free_all_nodes(*node_allocator_,branch);
+
+               return error_node();
+            }
+
+            typedef typename details::function_N_node<T,ifunction_t,N> function_N_node_t;
+
+            // Attempt simple constant folding optimisation.
+
+            expression_node_ptr expression_point = node_allocator_->allocate<NodeType>(f);
+            function_N_node_t* func_node_ptr = dynamic_cast<function_N_node_t*>(expression_point);
+
+            if (0 == func_node_ptr)
+            {
+               free_all_nodes(*node_allocator_,branch);
+
+               return error_node();
+            }
+            else
+               func_node_ptr->init_branches(branch);
+
+            if (is_constant_foldable<N>(branch) && !f->has_side_effects())
+            {
+               Type v = expression_point->value();
+               details::free_node(*node_allocator_,expression_point);
+
+               return node_allocator_->allocate<literal_node_t>(v);
+            }
+
+            parser_->state_.activate_side_effect("synthesize_expression(function<NT,N>)");
+
+            return expression_point;
+         }
+
+         bool                     strength_reduction_enabled_;
+         details::node_allocator* node_allocator_;
+         synthesize_map_t         synthesize_map_;
+         unary_op_map_t*          unary_op_map_;
+         binary_op_map_t*         binary_op_map_;
+         inv_binary_op_map_t*     inv_binary_op_map_;
+         sf3_map_t*               sf3_map_;
+         sf4_map_t*               sf4_map_;
+         parser_t*                parser_;
+      };
+
+      inline void set_error(const parser_error::type& error_type)
+      {
+         error_list_.push_back(error_type);
+      }
+
+      inline void remove_last_error()
+      {
+         if (!error_list_.empty())
+         {
+            error_list_.pop_back();
+         }
+      }
+
+      inline void set_synthesis_error(const std::string& synthesis_error_message)
+      {
+         if (synthesis_error_.empty())
+         {
+            synthesis_error_ = synthesis_error_message;
+         }
+      }
+
+      inline void register_local_vars(expression<T>& e)
+      {
+         for (std::size_t i = 0; i < sem_.size(); ++i)
+         {
+            scope_element& se = sem_.get_element(i);
+
+            if (
+                 (scope_element::e_variable == se.type) ||
+                 (scope_element::e_vecelem  == se.type)
+               )
+            {
+               if (se.var_node)
+               {
+                  e.register_local_var(se.var_node);
+               }
+
+               if (se.data)
+               {
+                  e.register_local_data(se.data, 1, 0);
+               }
+            }
+            else if (scope_element::e_vector == se.type)
+            {
+               if (se.vec_node)
+               {
+                  e.register_local_var(se.vec_node);
+               }
+
+               if (se.data)
+               {
+                  e.register_local_data(se.data, se.size, 1);
+               }
+            }
+            #ifndef exprtk_disable_string_capabilities
+            else if (scope_element::e_string == se.type)
+            {
+               if (se.str_node)
+               {
+                  e.register_local_var(se.str_node);
+               }
+
+               if (se.data)
+               {
+                  e.register_local_data(se.data, se.size, 2);
+               }
+            }
+            #endif
+
+            se.var_node  = 0;
+            se.vec_node  = 0;
+            #ifndef exprtk_disable_string_capabilities
+            se.str_node  = 0;
+            #endif
+            se.data      = 0;
+            se.ref_count = 0;
+            se.active    = false;
+         }
+      }
+
+      inline void register_return_results(expression<T>& e)
+      {
+         e.register_return_results(results_context_);
+         results_context_ = 0;
+      }
+
+      inline void load_unary_operations_map(unary_op_map_t& m)
+      {
+         #define register_unary_op(Op,UnaryFunctor)             \
+         m.insert(std::make_pair(Op,UnaryFunctor<T>::process)); \
+
+         register_unary_op(details::  e_abs, details::  abs_op)
+         register_unary_op(details:: e_acos, details:: acos_op)
+         register_unary_op(details::e_acosh, details::acosh_op)
+         register_unary_op(details:: e_asin, details:: asin_op)
+         register_unary_op(details::e_asinh, details::asinh_op)
+         register_unary_op(details::e_atanh, details::atanh_op)
+         register_unary_op(details:: e_ceil, details:: ceil_op)
+         register_unary_op(details::  e_cos, details::  cos_op)
+         register_unary_op(details:: e_cosh, details:: cosh_op)
+         register_unary_op(details::  e_exp, details::  exp_op)
+         register_unary_op(details::e_expm1, details::expm1_op)
+         register_unary_op(details::e_floor, details::floor_op)
+         register_unary_op(details::  e_log, details::  log_op)
+         register_unary_op(details::e_log10, details::log10_op)
+         register_unary_op(details:: e_log2, details:: log2_op)
+         register_unary_op(details::e_log1p, details::log1p_op)
+         register_unary_op(details::  e_neg, details::  neg_op)
+         register_unary_op(details::  e_pos, details::  pos_op)
+         register_unary_op(details::e_round, details::round_op)
+         register_unary_op(details::  e_sin, details::  sin_op)
+         register_unary_op(details:: e_sinc, details:: sinc_op)
+         register_unary_op(details:: e_sinh, details:: sinh_op)
+         register_unary_op(details:: e_sqrt, details:: sqrt_op)
+         register_unary_op(details::  e_tan, details::  tan_op)
+         register_unary_op(details:: e_tanh, details:: tanh_op)
+         register_unary_op(details::  e_cot, details::  cot_op)
+         register_unary_op(details::  e_sec, details::  sec_op)
+         register_unary_op(details::  e_csc, details::  csc_op)
+         register_unary_op(details::  e_r2d, details::  r2d_op)
+         register_unary_op(details::  e_d2r, details::  d2r_op)
+         register_unary_op(details::  e_d2g, details::  d2g_op)
+         register_unary_op(details::  e_g2d, details::  g2d_op)
+         register_unary_op(details:: e_notl, details:: notl_op)
+         register_unary_op(details::  e_sgn, details::  sgn_op)
+         register_unary_op(details::  e_erf, details::  erf_op)
+         register_unary_op(details:: e_erfc, details:: erfc_op)
+         register_unary_op(details:: e_ncdf, details:: ncdf_op)
+         register_unary_op(details:: e_frac, details:: frac_op)
+         register_unary_op(details::e_trunc, details::trunc_op)
+         #undef register_unary_op
+      }
+
+      inline void load_binary_operations_map(binary_op_map_t& m)
+      {
+         typedef typename binary_op_map_t::value_type value_type;
+
+         #define register_binary_op(Op,BinaryFunctor)        \
+         m.insert(value_type(Op,BinaryFunctor<T>::process)); \
+
+         register_binary_op(details:: e_add, details:: add_op)
+         register_binary_op(details:: e_sub, details:: sub_op)
+         register_binary_op(details:: e_mul, details:: mul_op)
+         register_binary_op(details:: e_div, details:: div_op)
+         register_binary_op(details:: e_mod, details:: mod_op)
+         register_binary_op(details:: e_pow, details:: pow_op)
+         register_binary_op(details::  e_lt, details::  lt_op)
+         register_binary_op(details:: e_lte, details:: lte_op)
+         register_binary_op(details::  e_gt, details::  gt_op)
+         register_binary_op(details:: e_gte, details:: gte_op)
+         register_binary_op(details::  e_eq, details::  eq_op)
+         register_binary_op(details::  e_ne, details::  ne_op)
+         register_binary_op(details:: e_and, details:: and_op)
+         register_binary_op(details::e_nand, details::nand_op)
+         register_binary_op(details::  e_or, details::  or_op)
+         register_binary_op(details:: e_nor, details:: nor_op)
+         register_binary_op(details:: e_xor, details:: xor_op)
+         register_binary_op(details::e_xnor, details::xnor_op)
+         #undef register_binary_op
+      }
+
+      inline void load_inv_binary_operations_map(inv_binary_op_map_t& m)
+      {
+         typedef typename inv_binary_op_map_t::value_type value_type;
+
+         #define register_binary_op(Op,BinaryFunctor)        \
+         m.insert(value_type(BinaryFunctor<T>::process,Op)); \
+
+         register_binary_op(details:: e_add, details:: add_op)
+         register_binary_op(details:: e_sub, details:: sub_op)
+         register_binary_op(details:: e_mul, details:: mul_op)
+         register_binary_op(details:: e_div, details:: div_op)
+         register_binary_op(details:: e_mod, details:: mod_op)
+         register_binary_op(details:: e_pow, details:: pow_op)
+         register_binary_op(details::  e_lt, details::  lt_op)
+         register_binary_op(details:: e_lte, details:: lte_op)
+         register_binary_op(details::  e_gt, details::  gt_op)
+         register_binary_op(details:: e_gte, details:: gte_op)
+         register_binary_op(details::  e_eq, details::  eq_op)
+         register_binary_op(details::  e_ne, details::  ne_op)
+         register_binary_op(details:: e_and, details:: and_op)
+         register_binary_op(details::e_nand, details::nand_op)
+         register_binary_op(details::  e_or, details::  or_op)
+         register_binary_op(details:: e_nor, details:: nor_op)
+         register_binary_op(details:: e_xor, details:: xor_op)
+         register_binary_op(details::e_xnor, details::xnor_op)
+         #undef register_binary_op
+      }
+
+      inline void load_sf3_map(sf3_map_t& sf3_map)
+      {
+         typedef std::pair<trinary_functor_t,details::operator_type> pair_t;
+
+         #define register_sf3(Op)                                                                             \
+         sf3_map[details::sf##Op##_op<T>::id()] = pair_t(details::sf##Op##_op<T>::process,details::e_sf##Op); \
+
+         register_sf3(00) register_sf3(01) register_sf3(02) register_sf3(03)
+         register_sf3(04) register_sf3(05) register_sf3(06) register_sf3(07)
+         register_sf3(08) register_sf3(09) register_sf3(10) register_sf3(11)
+         register_sf3(12) register_sf3(13) register_sf3(14) register_sf3(15)
+         register_sf3(16) register_sf3(17) register_sf3(18) register_sf3(19)
+         register_sf3(20) register_sf3(21) register_sf3(22) register_sf3(23)
+         register_sf3(24) register_sf3(25) register_sf3(26) register_sf3(27)
+         register_sf3(28) register_sf3(29) register_sf3(30)
+         #undef register_sf3
+
+         #define register_sf3_extid(Id, Op)                                        \
+         sf3_map[Id] = pair_t(details::sf##Op##_op<T>::process,details::e_sf##Op); \
+
+         register_sf3_extid("(t-t)-t",23)  // (t-t)-t --> t-(t+t)
+         #undef register_sf3_extid
+      }
+
+      inline void load_sf4_map(sf4_map_t& sf4_map)
+      {
+         typedef std::pair<quaternary_functor_t,details::operator_type> pair_t;
+
+         #define register_sf4(Op)                                                                             \
+         sf4_map[details::sf##Op##_op<T>::id()] = pair_t(details::sf##Op##_op<T>::process,details::e_sf##Op); \
+
+         register_sf4(48) register_sf4(49) register_sf4(50) register_sf4(51)
+         register_sf4(52) register_sf4(53) register_sf4(54) register_sf4(55)
+         register_sf4(56) register_sf4(57) register_sf4(58) register_sf4(59)
+         register_sf4(60) register_sf4(61) register_sf4(62) register_sf4(63)
+         register_sf4(64) register_sf4(65) register_sf4(66) register_sf4(67)
+         register_sf4(68) register_sf4(69) register_sf4(70) register_sf4(71)
+         register_sf4(72) register_sf4(73) register_sf4(74) register_sf4(75)
+         register_sf4(76) register_sf4(77) register_sf4(78) register_sf4(79)
+         register_sf4(80) register_sf4(81) register_sf4(82) register_sf4(83)
+         #undef register_sf4
+
+         #define register_sf4ext(Op)                                                                                    \
+         sf4_map[details::sfext##Op##_op<T>::id()] = pair_t(details::sfext##Op##_op<T>::process,details::e_sf4ext##Op); \
+
+         register_sf4ext(00) register_sf4ext(01) register_sf4ext(02) register_sf4ext(03)
+         register_sf4ext(04) register_sf4ext(05) register_sf4ext(06) register_sf4ext(07)
+         register_sf4ext(08) register_sf4ext(09) register_sf4ext(10) register_sf4ext(11)
+         register_sf4ext(12) register_sf4ext(13) register_sf4ext(14) register_sf4ext(15)
+         register_sf4ext(16) register_sf4ext(17) register_sf4ext(18) register_sf4ext(19)
+         register_sf4ext(20) register_sf4ext(21) register_sf4ext(22) register_sf4ext(23)
+         register_sf4ext(24) register_sf4ext(25) register_sf4ext(26) register_sf4ext(27)
+         register_sf4ext(28) register_sf4ext(29) register_sf4ext(30) register_sf4ext(31)
+         register_sf4ext(32) register_sf4ext(33) register_sf4ext(34) register_sf4ext(35)
+         register_sf4ext(36) register_sf4ext(36) register_sf4ext(38) register_sf4ext(39)
+         register_sf4ext(40) register_sf4ext(41) register_sf4ext(42) register_sf4ext(43)
+         register_sf4ext(44) register_sf4ext(45) register_sf4ext(46) register_sf4ext(47)
+         register_sf4ext(48) register_sf4ext(49) register_sf4ext(50) register_sf4ext(51)
+         register_sf4ext(52) register_sf4ext(53) register_sf4ext(54) register_sf4ext(55)
+         register_sf4ext(56) register_sf4ext(57) register_sf4ext(58) register_sf4ext(59)
+         register_sf4ext(60) register_sf4ext(61)
+         #undef register_sf4ext
+      }
+
+      inline results_context_t& results_ctx()
+      {
+         if (0 == results_context_)
+         {
+            results_context_ = new results_context_t();
+         }
+
+         return (*results_context_);
+      }
+
+      inline void return_cleanup()
+      {
+         #ifndef exprtk_disable_return_statement
+         if (results_context_)
+         {
+            delete results_context_;
+            results_context_ = 0;
+         }
+
+         state_.return_stmt_present = false;
+         #endif
+      }
+
+   private:
+
+      parser(const parser<T>&);
+      parser<T>& operator=(const parser<T>&);
+
+      settings_store settings_;
+      expression_generator<T> expression_generator_;
+      details::node_allocator node_allocator_;
+      symtab_store symtab_store_;
+      dependent_entity_collector dec_;
+      std::deque<parser_error::type> error_list_;
+      std::deque<bool> brkcnt_list_;
+      parser_state state_;
+      bool resolve_unknown_symbol_;
+      results_context_t* results_context_;
+      unknown_symbol_resolver* unknown_symbol_resolver_;
+      unknown_symbol_resolver default_usr_;
+      base_ops_map_t base_ops_map_;
+      unary_op_map_t unary_op_map_;
+      binary_op_map_t binary_op_map_;
+      inv_binary_op_map_t inv_binary_op_map_;
+      sf3_map_t sf3_map_;
+      sf4_map_t sf4_map_;
+      std::string synthesis_error_;
+      scope_element_manager sem_;
+
+      lexer::helper::helper_assembly helper_assembly_;
+
+      lexer::helper::commutative_inserter       commutative_inserter_;
+      lexer::helper::operator_joiner            operator_joiner_2_;
+      lexer::helper::operator_joiner            operator_joiner_3_;
+      lexer::helper::symbol_replacer            symbol_replacer_;
+      lexer::helper::bracket_checker            bracket_checker_;
+      lexer::helper::numeric_checker            numeric_checker_;
+      lexer::helper::sequence_validator         sequence_validator_;
+      lexer::helper::sequence_validator_3tokens sequence_validator_3tkns_;
+
+      template <typename ParserType>
+      friend void details::disable_type_checking(ParserType& p);
+   };
+
+   namespace details
+   {
+      template <typename T>
+      struct collector_helper
+      {
+         typedef exprtk::symbol_table<T> symbol_table_t;
+         typedef exprtk::expression<T>     expression_t;
+         typedef exprtk::parser<T>             parser_t;
+         typedef typename parser_t::dependent_entity_collector::symbol_t symbol_t;
+         typedef typename parser_t::unknown_symbol_resolver usr_t;
+
+         struct resolve_as_vector : public parser_t::unknown_symbol_resolver
+         {
+            typedef exprtk::parser<T> parser_t;
+
+            resolve_as_vector()
+            : usr_t(usr_t::e_usrmode_extended)
+            {}
+
+            virtual bool process(const std::string& unknown_symbol,
+                                 symbol_table_t& symbol_table,
+                                 std::string&)
+            {
+               static T v[1];
+               symbol_table.add_vector(unknown_symbol,v);
+               return true;
+            }
+         };
+
+         static inline bool collection_pass(const std::string& expression_string,
+                                            std::set<std::string>& symbol_set,
+                                            const bool collect_variables,
+                                            const bool collect_functions,
+                                            const bool vector_pass,
+                                            symbol_table_t& ext_symbol_table)
+         {
+            symbol_table_t symbol_table;
+            expression_t   expression;
+            parser_t       parser;
+
+            resolve_as_vector vect_resolver;
+
+            expression.register_symbol_table(symbol_table    );
+            expression.register_symbol_table(ext_symbol_table);
+
+            if (vector_pass)
+               parser.enable_unknown_symbol_resolver(&vect_resolver);
+            else
+               parser.enable_unknown_symbol_resolver();
+
+            if (collect_variables)
+               parser.dec().collect_variables() = true;
+
+            if (collect_functions)
+               parser.dec().collect_functions() = true;
+
+            bool pass_result = false;
+
+            details::disable_type_checking(parser);
+
+            if (parser.compile(expression_string, expression))
+            {
+               pass_result = true;
+
+               std::deque<symbol_t> symb_list;
+               parser.dec().symbols(symb_list);
+
+               for (std::size_t i = 0; i < symb_list.size(); ++i)
+               {
+                  symbol_set.insert(symb_list[i].first);
+               }
+            }
+
+            return pass_result;
+         }
+      };
+   }
+
+   template <typename Allocator,
+             template <typename, typename> class Sequence>
+   inline bool collect_variables(const std::string& expression,
+                                 Sequence<std::string, Allocator>& symbol_list)
+   {
+      typedef double T;
+      typedef details::collector_helper<T> collect_t;
+
+      collect_t::symbol_table_t null_symbol_table;
+
+      std::set<std::string> symbol_set;
+
+      const bool variable_pass = collect_t::collection_pass
+                                    (expression, symbol_set, true, false, false, null_symbol_table);
+      const bool vector_pass   = collect_t::collection_pass
+                                    (expression, symbol_set, true, false,  true, null_symbol_table);
+
+      if (!variable_pass && !vector_pass)
+         return false;
+
+      std::set<std::string>::iterator itr = symbol_set.begin();
+
+      while (symbol_set.end() != itr)
+      {
+         symbol_list.push_back(*itr);
+         ++itr;
+      }
+
+      return true;
+   }
+
+   template <typename T,
+             typename Allocator,
+             template <typename, typename> class Sequence>
+   inline bool collect_variables(const std::string& expression,
+                                 exprtk::symbol_table<T>& extrnl_symbol_table,
+                                 Sequence<std::string, Allocator>& symbol_list)
+   {
+      typedef details::collector_helper<T> collect_t;
+
+      std::set<std::string> symbol_set;
+
+      const bool variable_pass = collect_t::collection_pass
+                                    (expression, symbol_set, true, false, false, extrnl_symbol_table);
+      const bool vector_pass   = collect_t::collection_pass
+                                    (expression, symbol_set, true, false,  true, extrnl_symbol_table);
+
+      if (!variable_pass && !vector_pass)
+         return false;
+
+      std::set<std::string>::iterator itr = symbol_set.begin();
+
+      while (symbol_set.end() != itr)
+      {
+         symbol_list.push_back(*itr);
+         ++itr;
+      }
+
+      return true;
+   }
+
+   template <typename Allocator,
+             template <typename, typename> class Sequence>
+   inline bool collect_functions(const std::string& expression,
+                                 Sequence<std::string, Allocator>& symbol_list)
+   {
+      typedef double T;
+      typedef details::collector_helper<T> collect_t;
+
+      collect_t::symbol_table_t null_symbol_table;
+
+      std::set<std::string> symbol_set;
+
+      const bool variable_pass = collect_t::collection_pass
+                                    (expression, symbol_set, false, true, false, null_symbol_table);
+      const bool vector_pass   = collect_t::collection_pass
+                                    (expression, symbol_set, false, true,  true, null_symbol_table);
+
+      if (!variable_pass && !vector_pass)
+         return false;
+
+      std::set<std::string>::iterator itr = symbol_set.begin();
+
+      while (symbol_set.end() != itr)
+      {
+         symbol_list.push_back(*itr);
+         ++itr;
+      }
+
+      return true;
+   }
+
+   template <typename T,
+             typename Allocator,
+             template <typename, typename> class Sequence>
+   inline bool collect_functions(const std::string& expression,
+                                 exprtk::symbol_table<T>& extrnl_symbol_table,
+                                 Sequence<std::string, Allocator>& symbol_list)
+   {
+      typedef details::collector_helper<T> collect_t;
+
+      std::set<std::string> symbol_set;
+
+      const bool variable_pass = collect_t::collection_pass
+                                    (expression, symbol_set, false, true, false, extrnl_symbol_table);
+      const bool vector_pass   = collect_t::collection_pass
+                                    (expression, symbol_set, false, true,  true, extrnl_symbol_table);
+
+      if (!variable_pass && !vector_pass)
+         return false;
+
+      std::set<std::string>::iterator itr = symbol_set.begin();
+
+      while (symbol_set.end() != itr)
+      {
+         symbol_list.push_back(*itr);
+         ++itr;
+      }
+
+      return true;
+   }
+
+   template <typename T>
+   inline T integrate(const expression<T>& e,
+                      T& x,
+                      const T& r0, const T& r1,
+                      const std::size_t number_of_intervals = 1000000)
+   {
+      if (r0 > r1)
+         return T(0);
+
+      const T h = (r1 - r0) / (T(2) * number_of_intervals);
+      T total_area = T(0);
+
+      for (std::size_t i = 0; i < number_of_intervals; ++i)
+      {
+         x = r0 + T(2) * i * h;
+         const T y0 = e.value(); x += h;
+         const T y1 = e.value(); x += h;
+         const T y2 = e.value(); x += h;
+         total_area += h * (y0 + T(4) * y1 + y2) / T(3);
+      }
+
+      return total_area;
+   }
+
+   template <typename T>
+   inline T integrate(const expression<T>& e,
+                      const std::string& variable_name,
+                      const T& r0, const T& r1,
+                      const std::size_t number_of_intervals = 1000000)
+   {
+      const symbol_table<T>& sym_table = e.get_symbol_table();
+
+      if (!sym_table.valid())
+         return std::numeric_limits<T>::quiet_NaN();
+
+      details::variable_node<T>* var = sym_table.get_variable(variable_name);
+
+      if (var)
+      {
+         T& x = var->ref();
+         T  x_original = x;
+         T result = integrate(e, x, r0, r1, number_of_intervals);
+         x = x_original;
+
+         return result;
+      }
+      else
+         return std::numeric_limits<T>::quiet_NaN();
+   }
+
+   template <typename T>
+   inline T derivative(const expression<T>& e,
+                       T& x,
+                       const T& h = T(0.00000001))
+   {
+      const T x_init = x;
+      const T _2h    = T(2) * h;
+
+      x = x_init + _2h;
+      const T y0 = e.value();
+      x = x_init +   h;
+      const T y1 = e.value();
+      x = x_init -   h;
+      const T y2 = e.value();
+      x = x_init - _2h;
+      const T y3 = e.value();
+      x = x_init;
+
+      return (-y0 + T(8) * (y1 - y2) + y3) / (T(12) * h);
+   }
+
+   template <typename T>
+   inline T second_derivative(const expression<T>& e,
+                              T& x,
+                              const T& h = T(0.00001))
+   {
+      const T x_init = x;
+      const T _2h    = T(2) * h;
+
+      const T y = e.value();
+      x = x_init + _2h;
+      const T y0 = e.value();
+      x = x_init +   h;
+      const T y1 = e.value();
+      x = x_init -   h;
+      const T y2 = e.value();
+      x = x_init - _2h;
+      const T y3 = e.value();
+      x = x_init;
+
+      return (-y0 + T(16) * (y1 + y2) - T(30) * y - y3) / (T(12) * h * h);
+   }
+
+   template <typename T>
+   inline T third_derivative(const expression<T>& e,
+                             T& x,
+                             const T& h = T(0.0001))
+   {
+      const T x_init = x;
+      const T _2h    = T(2) * h;
+
+      x = x_init + _2h;
+      const T y0 = e.value();
+      x = x_init +   h;
+      const T y1 = e.value();
+      x = x_init -   h;
+      const T y2 = e.value();
+      x = x_init - _2h;
+      const T y3 = e.value();
+      x = x_init;
+
+      return (y0 + T(2) * (y2 - y1) - y3) / (T(2) * h * h * h);
+   }
+
+   template <typename T>
+   inline T derivative(const expression<T>& e,
+                       const std::string& variable_name,
+                       const T& h = T(0.00000001))
+   {
+      const symbol_table<T>& sym_table = e.get_symbol_table();
+
+      if (!sym_table.valid())
+      {
+         return std::numeric_limits<T>::quiet_NaN();
+      }
+
+      details::variable_node<T>* var = sym_table.get_variable(variable_name);
+
+      if (var)
+      {
+         T& x = var->ref();
+         T x_original = x;
+         T result = derivative(e, x, h);
+         x = x_original;
+
+         return result;
+      }
+      else
+         return std::numeric_limits<T>::quiet_NaN();
+   }
+
+   template <typename T>
+   inline T second_derivative(const expression<T>& e,
+                              const std::string& variable_name,
+                              const T& h = T(0.00001))
+   {
+      const symbol_table<T>& sym_table = e.get_symbol_table();
+
+      if (!sym_table.valid())
+      {
+         return std::numeric_limits<T>::quiet_NaN();
+      }
+
+      details::variable_node<T>* var = sym_table.get_variable(variable_name);
+
+      if (var)
+      {
+         T& x = var->ref();
+         const T x_original = x;
+         const T result = second_derivative(e, x, h);
+         x = x_original;
+
+         return result;
+      }
+      else
+         return std::numeric_limits<T>::quiet_NaN();
+   }
+
+   template <typename T>
+   inline T third_derivative(const expression<T>& e,
+                             const std::string& variable_name,
+                             const T& h = T(0.0001))
+   {
+      const symbol_table<T>& sym_table = e.get_symbol_table();
+
+      if (!sym_table.valid())
+      {
+         return std::numeric_limits<T>::quiet_NaN();
+      }
+
+      details::variable_node<T>* var = sym_table.get_variable(variable_name);
+
+      if (var)
+      {
+         T& x = var->ref();
+         const T x_original = x;
+         const T result = third_derivative(e, x, h);
+         x = x_original;
+
+         return result;
+      }
+      else
+         return std::numeric_limits<T>::quiet_NaN();
+   }
+
+   /*
+      Note: The following 'compute' routines are simple helpers,
+      for quickly setting up the required pieces of code in order
+      to evaluate an expression. By virtue of how they operate
+      there will be an overhead with regards to their setup and
+      teardown and hence should not be used in time critical
+      sections of code.
+      Furthermore they only assume a small sub set of variables,
+      no string variables or user defined functions.
+   */
+   template <typename T>
+   inline bool compute(const std::string& expression_string, T& result)
+   {
+      // No variables
+      symbol_table<T> symbol_table;
+      symbol_table.add_constants();
+
+      expression<T> expression;
+      expression.register_symbol_table(symbol_table);
+
+      parser<T> parser;
+
+      if (parser.compile(expression_string,expression))
+      {
+         result = expression.value();
+
+         return true;
+      }
+      else
+         return false;
+   }
+
+   template <typename T>
+   inline bool compute(const std::string& expression_string,
+                       const T& x,
+                       T& result)
+   {
+      // Only 'x'
+      static const std::string x_var("x");
+
+      symbol_table<T> symbol_table;
+      symbol_table.add_constants();
+      symbol_table.add_constant(x_var,x);
+
+      expression<T> expression;
+      expression.register_symbol_table(symbol_table);
+
+      parser<T> parser;
+
+      if (parser.compile(expression_string,expression))
+      {
+         result = expression.value();
+
+         return true;
+      }
+      else
+         return false;
+   }
+
+   template <typename T>
+   inline bool compute(const std::string& expression_string,
+                       const T&x, const T& y,
+                       T& result)
+   {
+      // Only 'x' and 'y'
+      static const std::string x_var("x");
+      static const std::string y_var("y");
+
+      symbol_table<T> symbol_table;
+      symbol_table.add_constants();
+      symbol_table.add_constant(x_var,x);
+      symbol_table.add_constant(y_var,y);
+
+      expression<T> expression;
+      expression.register_symbol_table(symbol_table);
+
+      parser<T> parser;
+
+      if (parser.compile(expression_string,expression))
+      {
+         result = expression.value();
+
+         return true;
+      }
+      else
+         return false;
+   }
+
+   template <typename T>
+   inline bool compute(const std::string& expression_string,
+                       const T& x, const T& y, const T& z,
+                       T& result)
+   {
+      // Only 'x', 'y' or 'z'
+      static const std::string x_var("x");
+      static const std::string y_var("y");
+      static const std::string z_var("z");
+
+      symbol_table<T> symbol_table;
+      symbol_table.add_constants();
+      symbol_table.add_constant(x_var,x);
+      symbol_table.add_constant(y_var,y);
+      symbol_table.add_constant(z_var,z);
+
+      expression<T> expression;
+      expression.register_symbol_table(symbol_table);
+
+      parser<T> parser;
+
+      if (parser.compile(expression_string,expression))
+      {
+         result = expression.value();
+
+         return true;
+      }
+      else
+         return false;
+   }
+
+   template <typename T, std::size_t N>
+   class polynomial : public ifunction<T>
+   {
+   private:
+
+      template <typename Type, std::size_t NumberOfCoefficients>
+      struct poly_impl { };
+
+      template <typename Type>
+      struct poly_impl <Type,12>
+      {
+         static inline T evaluate(const Type x,
+                                  const Type c12, const Type c11, const Type c10, const Type c9, const Type c8,
+                                  const Type  c7, const Type  c6, const Type  c5, const Type c4, const Type c3,
+                                  const Type  c2, const Type  c1, const Type  c0)
+         {
+            // p(x) = c_12x^12 + c_11x^11 + c_10x^10 + c_9x^9 + c_8x^8 + c_7x^7 + c_6x^6 + c_5x^5 + c_4x^4 + c_3x^3 + c_2x^2 + c_1x^1 + c_0x^0
+            return ((((((((((((c12 * x + c11) * x + c10) * x + c9) * x + c8) * x + c7) * x + c6) * x + c5) * x + c4) * x + c3) * x + c2) * x + c1) * x + c0);
+         }
+      };
+
+      template <typename Type>
+      struct poly_impl <Type,11>
+      {
+         static inline T evaluate(const Type x,
+                                  const Type c11, const Type c10, const Type c9, const Type c8, const Type c7,
+                                  const Type c6,  const Type  c5, const Type c4, const Type c3, const Type c2,
+                                  const Type c1,  const Type  c0)
+         {
+            // p(x) = c_11x^11 + c_10x^10 + c_9x^9 + c_8x^8 + c_7x^7 + c_6x^6 + c_5x^5 + c_4x^4 + c_3x^3 + c_2x^2 + c_1x^1 + c_0x^0
+            return (((((((((((c11 * x + c10) * x + c9) * x + c8) * x + c7) * x + c6) * x + c5) * x + c4) * x + c3) * x + c2) * x + c1) * x + c0);
+         }
+      };
+
+      template <typename Type>
+      struct poly_impl <Type,10>
+      {
+         static inline T evaluate(const Type x,
+                                  const Type c10, const Type c9, const Type c8, const Type c7, const Type c6,
+                                  const Type c5,  const Type c4, const Type c3, const Type c2, const Type c1,
+                                  const Type c0)
+         {
+            // p(x) = c_10x^10 + c_9x^9 + c_8x^8 + c_7x^7 + c_6x^6 + c_5x^5 + c_4x^4 + c_3x^3 + c_2x^2 + c_1x^1 + c_0x^0
+            return ((((((((((c10 * x + c9) * x + c8) * x + c7) * x + c6) * x + c5) * x + c4) * x + c3) * x + c2) * x + c1) * x + c0);
+         }
+      };
+
+      template <typename Type>
+      struct poly_impl <Type,9>
+      {
+         static inline T evaluate(const Type x,
+                                  const Type c9, const Type c8, const Type c7, const Type c6, const Type c5,
+                                  const Type c4, const Type c3, const Type c2, const Type c1, const Type c0)
+         {
+            // p(x) = c_9x^9 + c_8x^8 + c_7x^7 + c_6x^6 + c_5x^5 + c_4x^4 + c_3x^3 + c_2x^2 + c_1x^1 + c_0x^0
+            return (((((((((c9 * x + c8) * x + c7) * x + c6) * x + c5) * x + c4) * x + c3) * x + c2) * x + c1) * x + c0);
+         }
+      };
+
+      template <typename Type>
+      struct poly_impl <Type,8>
+      {
+         static inline T evaluate(const Type x,
+                                  const Type c8, const Type c7, const Type c6, const Type c5, const Type c4,
+                                  const Type c3, const Type c2, const Type c1, const Type c0)
+         {
+            // p(x) = c_8x^8 + c_7x^7 + c_6x^6 + c_5x^5 + c_4x^4 + c_3x^3 + c_2x^2 + c_1x^1 + c_0x^0
+            return ((((((((c8 * x + c7) * x + c6) * x + c5) * x + c4) * x + c3) * x + c2) * x + c1) * x + c0);
+         }
+      };
+
+      template <typename Type>
+      struct poly_impl <Type,7>
+      {
+         static inline T evaluate(const Type x,
+                                  const Type c7, const Type c6, const Type c5, const Type c4, const Type c3,
+                                  const Type c2, const Type c1, const Type c0)
+         {
+            // p(x) = c_7x^7 + c_6x^6 + c_5x^5 + c_4x^4 + c_3x^3 + c_2x^2 + c_1x^1 + c_0x^0
+            return (((((((c7 * x + c6) * x + c5) * x + c4) * x + c3) * x + c2) * x + c1) * x + c0);
+         }
+      };
+
+      template <typename Type>
+      struct poly_impl <Type,6>
+      {
+         static inline T evaluate(const Type x,
+                                  const Type c6, const Type c5, const Type c4, const Type c3, const Type c2,
+                                  const Type c1, const Type c0)
+         {
+            // p(x) = c_6x^6 + c_5x^5 + c_4x^4 + c_3x^3 + c_2x^2 + c_1x^1 + c_0x^0
+            return ((((((c6 * x + c5) * x + c4) * x + c3) * x + c2) * x + c1) * x + c0);
+         }
+      };
+
+      template <typename Type>
+      struct poly_impl <Type,5>
+      {
+         static inline T evaluate(const Type x,
+                                  const Type c5, const Type c4, const Type c3, const Type c2,
+                                  const Type c1, const Type c0)
+         {
+            // p(x) = c_5x^5 + c_4x^4 + c_3x^3 + c_2x^2 + c_1x^1 + c_0x^0
+            return (((((c5 * x + c4) * x + c3) * x + c2) * x + c1) * x + c0);
+         }
+      };
+
+      template <typename Type>
+      struct poly_impl <Type,4>
+      {
+         static inline T evaluate(const Type x, const Type c4, const Type c3, const Type c2, const Type c1, const Type c0)
+         {
+            // p(x) = c_4x^4 + c_3x^3 + c_2x^2 + c_1x^1 + c_0x^0
+            return ((((c4 * x + c3) * x + c2) * x + c1) * x + c0);
+         }
+      };
+
+      template <typename Type>
+      struct poly_impl <Type,3>
+      {
+         static inline T evaluate(const Type x, const Type c3, const Type c2, const Type c1, const Type c0)
+         {
+            // p(x) = c_3x^3 + c_2x^2 + c_1x^1 + c_0x^0
+            return (((c3 * x + c2) * x + c1) * x + c0);
+         }
+      };
+
+      template <typename Type>
+      struct poly_impl <Type,2>
+      {
+         static inline T evaluate(const Type x, const Type c2, const Type c1, const Type c0)
+         {
+            // p(x) = c_2x^2 + c_1x^1 + c_0x^0
+            return ((c2 * x + c1) * x + c0);
+         }
+      };
+
+      template <typename Type>
+      struct poly_impl <Type,1>
+      {
+         static inline T evaluate(const Type x, const Type c1, const Type c0)
+         {
+            // p(x) = c_1x^1 + c_0x^0
+            return (c1 * x + c0);
+         }
+      };
+
+   public:
+
+      using ifunction<T>::operator();
+
+      polynomial()
+      : ifunction<T>((N+2 <= 20) ? (N + 2) : std::numeric_limits<std::size_t>::max())
+      {
+         disable_has_side_effects(*this);
+      }
+
+      virtual ~polynomial()
+      {}
+
+      #define poly_rtrn(NN) \
+      return (NN != N) ? std::numeric_limits<T>::quiet_NaN() :
+
+      inline virtual T operator() (const T& x, const T& c1, const T& c0)
+      {
+         poly_rtrn(1) poly_impl<T,1>::evaluate(x, c1, c0);
+      }
+
+      inline virtual T operator() (const T& x, const T& c2, const T& c1, const T& c0)
+      {
+         poly_rtrn(2) poly_impl<T,2>::evaluate(x, c2, c1, c0);
+      }
+
+      inline virtual T operator() (const T& x, const T& c3, const T& c2, const T& c1, const T& c0)
+      {
+         poly_rtrn(3) poly_impl<T,3>::evaluate(x, c3, c2, c1, c0);
+      }
+
+      inline virtual T operator() (const T& x, const T& c4, const T& c3, const T& c2, const T& c1, const T& c0)
+      {
+         poly_rtrn(4) poly_impl<T,4>::evaluate(x, c4, c3, c2, c1, c0);
+      }
+
+      inline virtual T operator() (const T& x, const T& c5, const T& c4, const T& c3, const T& c2, const T& c1, const T& c0)
+      {
+         poly_rtrn(5) poly_impl<T,5>::evaluate(x, c5, c4, c3, c2, c1, c0);
+      }
+
+      inline virtual T operator() (const T& x, const T& c6, const T& c5, const T& c4, const T& c3, const T& c2, const T& c1, const T& c0)
+      {
+         poly_rtrn(6) poly_impl<T,6>::evaluate(x, c6, c5, c4, c3, c2, c1, c0);
+      }
+
+      inline virtual T operator() (const T& x, const T& c7, const T& c6, const T& c5, const T& c4, const T& c3, const T& c2, const T& c1, const T& c0)
+      {
+         poly_rtrn(7) poly_impl<T,7>::evaluate(x, c7, c6, c5, c4, c3, c2, c1, c0);
+      }
+
+      inline virtual T operator() (const T& x, const T& c8, const T& c7, const T& c6, const T& c5, const T& c4, const T& c3, const T& c2, const T& c1, const T& c0)
+      {
+         poly_rtrn(8) poly_impl<T,8>::evaluate(x, c8, c7, c6, c5, c4, c3, c2, c1, c0);
+      }
+
+      inline virtual T operator() (const T& x, const T& c9, const T& c8, const T& c7, const T& c6, const T& c5, const T& c4, const T& c3, const T& c2, const T& c1, const T& c0)
+      {
+         poly_rtrn(9) poly_impl<T,9>::evaluate(x, c9, c8, c7, c6, c5, c4, c3, c2, c1, c0);
+      }
+
+      inline virtual T operator() (const T& x, const T& c10, const T& c9, const T& c8, const T& c7, const T& c6, const T& c5, const T& c4, const T& c3, const T& c2, const T& c1, const T& c0)
+      {
+         poly_rtrn(10) poly_impl<T,10>::evaluate(x, c10, c9, c8, c7, c6, c5, c4, c3, c2, c1, c0);
+      }
+
+      inline virtual T operator() (const T& x, const T& c11, const T& c10, const T& c9, const T& c8, const T& c7, const T& c6, const T& c5, const T& c4, const T& c3, const T& c2, const T& c1, const T& c0)
+      {
+         poly_rtrn(11) poly_impl<T,11>::evaluate(x, c11, c10, c9, c8, c7, c6, c5, c4, c3, c2, c1, c0);
+      }
+
+      inline virtual T operator() (const T& x, const T& c12, const T& c11, const T& c10, const T& c9, const T& c8, const T& c7, const T& c6, const T& c5, const T& c4, const T& c3, const T& c2, const T& c1, const T& c0)
+      {
+         poly_rtrn(12) poly_impl<T,12>::evaluate(x, c12, c11, c10, c9, c8, c7, c6, c5, c4, c3, c2, c1, c0);
+      }
+
+      #undef poly_rtrn
+
+      inline virtual T operator() ()
+      {
+         return std::numeric_limits<T>::quiet_NaN();
+      }
+
+      inline virtual T operator() (const T&)
+      {
+         return std::numeric_limits<T>::quiet_NaN();
+      }
+
+      inline virtual T operator() (const T&, const T&)
+      {
+         return std::numeric_limits<T>::quiet_NaN();
+      }
+   };
+
+   template <typename T>
+   class function_compositor
+   {
+   public:
+
+      typedef exprtk::expression<T>             expression_t;
+      typedef exprtk::symbol_table<T>           symbol_table_t;
+      typedef exprtk::parser<T>                 parser_t;
+      typedef typename parser_t::settings_store settings_t;
+
+      struct function
+      {
+         function()
+         {}
+
+         function(const std::string& n)
+         : name_(n)
+         {}
+
+         function(const std::string& name,
+                  const std::string& expression)
+         : name_(name),
+           expression_(expression)
+         {}
+
+         function(const std::string& name,
+                  const std::string& expression,
+                  const std::string& v0)
+         : name_(name),
+           expression_(expression)
+         {
+            v_.push_back(v0);
+         }
+
+         function(const std::string& name,
+                  const std::string& expression,
+                  const std::string& v0, const std::string& v1)
+         : name_(name),
+           expression_(expression)
+         {
+            v_.push_back(v0); v_.push_back(v1);
+         }
+
+         function(const std::string& name,
+                  const std::string& expression,
+                  const std::string& v0, const std::string& v1,
+                  const std::string& v2)
+         : name_(name),
+           expression_(expression)
+         {
+            v_.push_back(v0); v_.push_back(v1);
+            v_.push_back(v2);
+         }
+
+         function(const std::string& name,
+                  const std::string& expression,
+                  const std::string& v0, const std::string& v1,
+                  const std::string& v2, const std::string& v3)
+         : name_(name),
+           expression_(expression)
+         {
+            v_.push_back(v0); v_.push_back(v1);
+            v_.push_back(v2); v_.push_back(v3);
+         }
+
+         function(const std::string& name,
+                  const std::string& expression,
+                  const std::string& v0, const std::string& v1,
+                  const std::string& v2, const std::string& v3,
+                  const std::string& v4)
+         : name_(name),
+           expression_(expression)
+         {
+            v_.push_back(v0); v_.push_back(v1);
+            v_.push_back(v2); v_.push_back(v3);
+            v_.push_back(v4);
+         }
+
+         inline function& name(const std::string& n)
+         {
+            name_ = n;
+            return (*this);
+         }
+
+         inline function& expression(const std::string& e)
+         {
+            expression_ = e;
+            return (*this);
+         }
+
+         inline function& var(const std::string& v)
+         {
+            v_.push_back(v);
+            return (*this);
+         }
+
+         std::string name_;
+         std::string expression_;
+         std::deque<std::string> v_;
+      };
+
+   private:
+
+      struct base_func : public exprtk::ifunction<T>
+      {
+         typedef const T&                       type;
+         typedef exprtk::ifunction<T>     function_t;
+         typedef std::vector<T*>            varref_t;
+         typedef std::vector<T>                var_t;
+         typedef std::pair<T*,std::size_t> lvarref_t;
+         typedef std::vector<lvarref_t>    lvr_vec_t;
+
+         using exprtk::ifunction<T>::operator();
+
+         base_func(const std::size_t& pc = 0)
+         : exprtk::ifunction<T>(pc),
+           local_var_stack_size(0),
+           stack_depth(0)
+         {
+            v.resize(pc);
+         }
+
+         virtual ~base_func()
+         {}
+
+         inline void update(const T& v0)
+         {
+            (*v[0]) = v0;
+         }
+
+         inline void update(const T& v0, const T& v1)
+         {
+            (*v[0]) = v0; (*v[1]) = v1;
+         }
+
+         inline void update(const T& v0, const T& v1, const T& v2)
+         {
+            (*v[0]) = v0; (*v[1]) = v1;
+            (*v[2]) = v2;
+         }
+
+         inline void update(const T& v0, const T& v1, const T& v2, const T& v3)
+         {
+            (*v[0]) = v0; (*v[1]) = v1;
+            (*v[2]) = v2; (*v[3]) = v3;
+         }
+
+         inline void update(const T& v0, const T& v1, const T& v2, const T& v3, const T& v4)
+         {
+            (*v[0]) = v0; (*v[1]) = v1;
+            (*v[2]) = v2; (*v[3]) = v3;
+            (*v[4]) = v4;
+         }
+
+         inline void update(const T& v0, const T& v1, const T& v2, const T& v3, const T& v4, const T& v5)
+         {
+            (*v[0]) = v0; (*v[1]) = v1;
+            (*v[2]) = v2; (*v[3]) = v3;
+            (*v[4]) = v4; (*v[5]) = v5;
+         }
+
+         inline function_t& setup(expression_t& expr)
+         {
+            expression = expr;
+
+            typedef typename expression_t::control_block::local_data_list_t ldl_t;
+
+            ldl_t ldl = expr.local_data_list();
+
+            std::vector<std::size_t> index_list;
+
+            for (std::size_t i = 0; i < ldl.size(); ++i)
+            {
+               if (ldl[i].size)
+               {
+                  index_list.push_back(i);
+               }
+            }
+
+            std::size_t input_param_count = 0;
+
+            for (std::size_t i = 0; i < index_list.size(); ++i)
+            {
+               const std::size_t index = index_list[i];
+
+               if (i < (index_list.size() - v.size()))
+               {
+                  lv.push_back(
+                        std::make_pair(
+                           reinterpret_cast<T*>(ldl[index].pointer),
+                           ldl[index].size));
+
+                  local_var_stack_size += ldl[index].size;
+               }
+               else
+                  v[input_param_count++] = reinterpret_cast<T*>(ldl[index].pointer);
+            }
+
+            clear_stack();
+
+            return (*this);
+         }
+
+         inline void pre()
+         {
+            if (stack_depth++)
+            {
+               if (!v.empty())
+               {
+                  var_t var_stack(v.size(),T(0));
+                  copy(v,var_stack);
+                  param_stack.push_back(var_stack);
+               }
+
+               if (!lv.empty())
+               {
+                  var_t local_var_stack(local_var_stack_size,T(0));
+                  copy(lv,local_var_stack);
+                  local_stack.push_back(local_var_stack);
+               }
+            }
+         }
+
+         inline void post()
+         {
+            if (--stack_depth)
+            {
+               if (!v.empty())
+               {
+                  copy(param_stack.back(),v);
+                  param_stack.pop_back();
+               }
+
+               if (!lv.empty())
+               {
+                  copy(local_stack.back(),lv);
+                  local_stack.pop_back();
+               }
+            }
+         }
+
+         void copy(const varref_t& src_v, var_t& dest_v)
+         {
+            for (std::size_t i = 0; i < src_v.size(); ++i)
+            {
+               dest_v[i] = (*src_v[i]);
+            }
+         }
+
+         void copy(const var_t& src_v, varref_t& dest_v)
+         {
+            for (std::size_t i = 0; i < src_v.size(); ++i)
+            {
+               (*dest_v[i]) = src_v[i];
+            }
+         }
+
+         void copy(const lvr_vec_t& src_v, var_t& dest_v)
+         {
+            typename var_t::iterator itr = dest_v.begin();
+            typedef  typename std::iterator_traits<typename var_t::iterator>::difference_type diff_t;
+
+            for (std::size_t i = 0; i < src_v.size(); ++i)
+            {
+               lvarref_t vr = src_v[i];
+
+               if (1 == vr.second)
+                  *itr++ = (*vr.first);
+               else
+               {
+                  std::copy(vr.first, vr.first + vr.second, itr);
+                  itr += static_cast<diff_t>(vr.second);
+               }
+            }
+         }
+
+         void copy(const var_t& src_v, lvr_vec_t& dest_v)
+         {
+            typename var_t::const_iterator itr = src_v.begin();
+            typedef  typename std::iterator_traits<typename var_t::iterator>::difference_type diff_t;
+
+            for (std::size_t i = 0; i < src_v.size(); ++i)
+            {
+               lvarref_t vr = dest_v[i];
+
+               if (1 == vr.second)
+                  (*vr.first) = *itr++;
+               else
+               {
+                  std::copy(itr, itr + static_cast<diff_t>(vr.second), vr.first);
+                  itr += static_cast<diff_t>(vr.second);
+               }
+            }
+         }
+
+         inline void clear_stack()
+         {
+            for (std::size_t i = 0; i < v.size(); ++i)
+            {
+               (*v[i]) = 0;
+            }
+         }
+
+         inline virtual T value(expression_t& e)
+         {
+            return e.value();
+         }
+
+         expression_t expression;
+         varref_t v;
+         lvr_vec_t lv;
+         std::size_t local_var_stack_size;
+         std::size_t stack_depth;
+         std::deque<var_t> param_stack;
+         std::deque<var_t> local_stack;
+      };
+
+      typedef std::map<std::string,base_func*> funcparam_t;
+
+      struct func_0param : public base_func
+      {
+         using exprtk::ifunction<T>::operator();
+
+         func_0param() : base_func(0) {}
+
+         inline T operator() ()
+         {
+            return this->value(base_func::expression);
+         }
+      };
+
+      typedef const T& type;
+
+      template <typename BaseFuncType>
+      struct scoped_bft
+      {
+         scoped_bft(BaseFuncType& bft) : bft_(bft) { bft_.pre (); }
+        ~scoped_bft()                              { bft_.post(); }
+
+         BaseFuncType& bft_;
+
+      private:
+
+         scoped_bft(scoped_bft&);
+         scoped_bft& operator=(scoped_bft&);
+      };
+
+      struct func_1param : public base_func
+      {
+         using exprtk::ifunction<T>::operator();
+
+         func_1param() : base_func(1) {}
+
+         inline T operator() (type v0)
+         {
+            scoped_bft<func_1param> sb(*this);
+            base_func::update(v0);
+            return this->value(base_func::expression);
+         }
+      };
+
+      struct func_2param : public base_func
+      {
+         using exprtk::ifunction<T>::operator();
+
+         func_2param() : base_func(2) {}
+
+         inline T operator() (type v0, type v1)
+         {
+            scoped_bft<func_2param> sb(*this);
+            base_func::update(v0, v1);
+            return this->value(base_func::expression);
+         }
+      };
+
+      struct func_3param : public base_func
+      {
+         using exprtk::ifunction<T>::operator();
+
+         func_3param() : base_func(3) {}
+
+         inline T operator() (type v0, type v1, type v2)
+         {
+            scoped_bft<func_3param> sb(*this);
+            base_func::update(v0, v1, v2);
+            return this->value(base_func::expression);
+         }
+      };
+
+      struct func_4param : public base_func
+      {
+         using exprtk::ifunction<T>::operator();
+
+         func_4param() : base_func(4) {}
+
+         inline T operator() (type v0, type v1, type v2, type v3)
+         {
+            scoped_bft<func_4param> sb(*this);
+            base_func::update(v0, v1, v2, v3);
+            return this->value(base_func::expression);
+         }
+      };
+
+      struct func_5param : public base_func
+      {
+         using exprtk::ifunction<T>::operator();
+
+         func_5param() : base_func(5) {}
+
+         inline T operator() (type v0, type v1, type v2, type v3, type v4)
+         {
+            scoped_bft<func_5param> sb(*this);
+            base_func::update(v0, v1, v2, v3, v4);
+            return this->value(base_func::expression);
+         }
+      };
+
+      struct func_6param : public base_func
+      {
+         using exprtk::ifunction<T>::operator();
+
+         func_6param() : base_func(6) {}
+
+         inline T operator() (type v0, type v1, type v2, type v3, type v4, type v5)
+         {
+            scoped_bft<func_6param> sb(*this);
+            base_func::update(v0, v1, v2, v3, v4, v5);
+            return this->value(base_func::expression);
+         }
+      };
+
+      static T return_value(expression_t& e)
+      {
+         typedef exprtk::results_context<T> results_context_t;
+         typedef typename results_context_t::type_store_t type_t;
+         typedef typename type_t::scalar_view scalar_t;
+
+         T result = e.value();
+
+         if (e.return_invoked())
+         {
+            // Due to the post compilation checks, it can be safely
+            // assumed that there will be at least one parameter
+            // and that the first parameter will always be scalar.
+            return scalar_t(e.results()[0])();
+         }
+
+         return result;
+      }
+
+      #define def_fp_retval(N)                               \
+      struct func_##N##param_retval : public func_##N##param \
+      {                                                      \
+         inline T value(expression_t& e)                     \
+         {                                                   \
+            return return_value(e);                          \
+         }                                                   \
+      };                                                     \
+
+      def_fp_retval(0)
+      def_fp_retval(1)
+      def_fp_retval(2)
+      def_fp_retval(3)
+      def_fp_retval(4)
+      def_fp_retval(5)
+      def_fp_retval(6)
+
+      template <typename Allocator,
+                template <typename, typename> class Sequence>
+      inline bool add(const std::string& name,
+                      const std::string& expression,
+                      const Sequence<std::string,Allocator>& var_list,
+                      const bool override = false)
+      {
+         const typename std::map<std::string,expression_t>::iterator itr = expr_map_.find(name);
+
+         if (expr_map_.end() != itr)
+         {
+            if (!override)
+            {
+               exprtk_debug(("Compositor error(add): function '%s' already defined\n",
+                             name.c_str()));
+
+               return false;
+            }
+
+            remove(name, var_list.size());
+         }
+
+         if (compile_expression(name,expression,var_list))
+         {
+            const std::size_t n = var_list.size();
+
+            fp_map_[n][name]->setup(expr_map_[name]);
+
+            return true;
+         }
+         else
+         {
+            exprtk_debug(("Compositor error(add): Failed to compile function '%s'\n",
+                          name.c_str()));
+
+            return false;
+         }
+      }
+
+   public:
+
+      function_compositor()
+      : parser_(settings_t::compile_all_opts +
+                settings_t::e_disable_zero_return),
+        fp_map_(7)
+      {}
+
+      function_compositor(const symbol_table_t& st)
+      : symbol_table_(st),
+        parser_(settings_t::compile_all_opts +
+                settings_t::e_disable_zero_return),
+        fp_map_(7)
+      {}
+
+     ~function_compositor()
+      {
+         clear();
+      }
+
+      inline symbol_table_t& symbol_table()
+      {
+         return symbol_table_;
+      }
+
+      inline void add_auxiliary_symtab(symbol_table_t& symtab)
+      {
+         auxiliary_symtab_list_.push_back(&symtab);
+      }
+
+      void clear()
+      {
+         symbol_table_.clear();
+         expr_map_    .clear();
+
+         for (std::size_t i = 0; i < fp_map_.size(); ++i)
+         {
+            typename funcparam_t::iterator itr = fp_map_[i].begin();
+            typename funcparam_t::iterator end = fp_map_[i].end  ();
+
+            while (itr != end)
+            {
+               delete itr->second;
+               ++itr;
+            }
+
+            fp_map_[i].clear();
+         }
+      }
+
+      inline bool add(const function& f, const bool override = false)
+      {
+         return add(f.name_, f.expression_, f.v_,override);
+      }
+
+   private:
+
+      template <typename Allocator,
+                template <typename, typename> class Sequence>
+      bool compile_expression(const std::string& name,
+                              const std::string& expression,
+                              const Sequence<std::string,Allocator>& input_var_list,
+                              bool  return_present = false)
+      {
+         expression_t compiled_expression;
+         symbol_table_t local_symbol_table;
+
+         local_symbol_table.load_from(symbol_table_);
+         local_symbol_table.add_constants();
+
+         if (!valid(name,input_var_list.size()))
+            return false;
+
+         if (!forward(name,
+                      input_var_list.size(),
+                      local_symbol_table,
+                      return_present))
+            return false;
+
+         compiled_expression.register_symbol_table(local_symbol_table);
+
+         for (std::size_t i = 0; i < auxiliary_symtab_list_.size(); ++i)
+         {
+            compiled_expression.register_symbol_table((*auxiliary_symtab_list_[i]));
+         }
+
+         std::string mod_expression;
+
+         for (std::size_t i = 0; i < input_var_list.size(); ++i)
+         {
+            mod_expression += " var " + input_var_list[i] + "{};\n";
+         }
+
+         if (
+              ('{' == details::front(expression)) &&
+              ('}' == details::back (expression))
+            )
+            mod_expression += "~" + expression + ";";
+         else
+            mod_expression += "~{" + expression + "};";
+
+         if (!parser_.compile(mod_expression,compiled_expression))
+         {
+            exprtk_debug(("Compositor Error: %s\n",parser_.error().c_str()));
+            exprtk_debug(("Compositor modified expression: \n%s\n",mod_expression.c_str()));
+
+            remove(name,input_var_list.size());
+
+            return false;
+         }
+
+         if (!return_present && parser_.dec().return_present())
+         {
+            remove(name,input_var_list.size());
+
+            return compile_expression(name, expression, input_var_list, true);
+         }
+
+         // Make sure every return point has a scalar as its first parameter
+         if (parser_.dec().return_present())
+         {
+            typedef std::vector<std::string> str_list_t;
+
+            str_list_t ret_param_list = parser_.dec().return_param_type_list();
+
+            for (std::size_t i = 0; i < ret_param_list.size(); ++i)
+            {
+               const std::string& params = ret_param_list[i];
+
+               if (params.empty() || ('T' != params[0]))
+               {
+                  exprtk_debug(("Compositor Error: Return statement in function '%s' is invalid\n",
+                                name.c_str()));
+
+                  remove(name,input_var_list.size());
+
+                  return false;
+               }
+            }
+         }
+
+         expr_map_[name] = compiled_expression;
+
+         exprtk::ifunction<T>& ifunc = (*(fp_map_[input_var_list.size()])[name]);
+
+         if (symbol_table_.add_function(name,ifunc))
+            return true;
+         else
+         {
+            exprtk_debug(("Compositor Error: Failed to add function '%s' to symbol table\n",
+                          name.c_str()));
+            return false;
+         }
+      }
+
+      inline bool symbol_used(const std::string& symbol) const
+      {
+         return (
+                  symbol_table_.is_variable       (symbol) ||
+                  symbol_table_.is_stringvar      (symbol) ||
+                  symbol_table_.is_function       (symbol) ||
+                  symbol_table_.is_vector         (symbol) ||
+                  symbol_table_.is_vararg_function(symbol)
+                );
+      }
+
+      inline bool valid(const std::string& name,
+                        const std::size_t& arg_count) const
+      {
+         if (arg_count > 6)
+            return false;
+         else if (symbol_used(name))
+            return false;
+         else if (fp_map_[arg_count].end() != fp_map_[arg_count].find(name))
+            return false;
+         else
+            return true;
+      }
+
+      inline bool forward(const std::string& name,
+                          const std::size_t& arg_count,
+                          symbol_table_t& sym_table,
+                          const bool ret_present = false)
+      {
+         switch (arg_count)
+         {
+            #define case_stmt(N)                                     \
+            case N : (fp_map_[arg_count])[name] =                    \
+                     (!ret_present) ? static_cast<base_func*>        \
+                                      (new func_##N##param) :        \
+                                      static_cast<base_func*>        \
+                                      (new func_##N##param_retval) ; \
+                     break;                                          \
+
+            case_stmt(0) case_stmt(1) case_stmt(2)
+            case_stmt(3) case_stmt(4) case_stmt(5)
+            case_stmt(6)
+            #undef case_stmt
+         }
+
+         exprtk::ifunction<T>& ifunc = (*(fp_map_[arg_count])[name]);
+
+         return sym_table.add_function(name,ifunc);
+      }
+
+      inline void remove(const std::string& name, const std::size_t& arg_count)
+      {
+         if (arg_count > 6)
+            return;
+
+         const typename std::map<std::string,expression_t>::iterator em_itr = expr_map_.find(name);
+
+         if (expr_map_.end() != em_itr)
+         {
+            expr_map_.erase(em_itr);
+         }
+
+         const typename funcparam_t::iterator fp_itr = fp_map_[arg_count].find(name);
+
+         if (fp_map_[arg_count].end() != fp_itr)
+         {
+            delete fp_itr->second;
+            fp_map_[arg_count].erase(fp_itr);
+         }
+
+         symbol_table_.remove_function(name);
+      }
+
+   private:
+
+      symbol_table_t symbol_table_;
+      parser_t parser_;
+      std::map<std::string,expression_t> expr_map_;
+      std::vector<funcparam_t> fp_map_;
+      std::vector<symbol_table_t*> auxiliary_symtab_list_;
+   };
+
+   template <typename T>
+   inline bool pgo_primer()
+   {
+      static const std::string expression_list[] =
+             {
+                "(y + x)",
+                "2 * (y + x)",
+                "(2 * y + 2 * x)",
+                "(y + x / y) * (x - y / x)",
+                "x / ((x + y) * (x - y)) / y",
+                "1 - ((x * y) + (y / x)) - 3",
+                "sin(2 * x) + cos(pi / y)",
+                "1 - sin(2 * x) + cos(pi / y)",
+                "sqrt(1 - sin(2 * x) + cos(pi / y) / 3)",
+                "(x^2 / sin(2 * pi / y)) -x / 2",
+                "x + (cos(y - sin(2 / x * pi)) - sin(x - cos(2 * y / pi))) - y",
+                "clamp(-1.0, sin(2 * pi * x) + cos(y / 2 * pi), +1.0)",
+                "iclamp(-1.0, sin(2 * pi * x) + cos(y / 2 * pi), +1.0)",
+                "max(3.33, min(sqrt(1 - sin(2 * x) + cos(pi / y) / 3), 1.11))",
+                "if(avg(x,y) <= x + y, x - y, x * y) + 2 * pi / x",
+                "1.1x^1 + 2.2y^2 - 3.3x^3 + 4.4y^4 - 5.5x^5 + 6.6y^6 - 7.7x^27 + 8.8y^55",
+                "(yy + xx)",
+                "2 * (yy + xx)",
+                "(2 * yy + 2 * xx)",
+                "(yy + xx / yy) * (xx - yy / xx)",
+                "xx / ((xx + yy) * (xx - yy)) / yy",
+                "1 - ((xx * yy) + (yy / xx)) - 3",
+                "sin(2 * xx) + cos(pi / yy)",
+                "1 - sin(2 * xx) + cos(pi / yy)",
+                "sqrt(1 - sin(2 * xx) + cos(pi / yy) / 3)",
+                "(xx^2 / sin(2 * pi / yy)) -xx / 2",
+                "xx + (cos(yy - sin(2 / xx * pi)) - sin(xx - cos(2 * yy / pi))) - yy",
+                "clamp(-1.0, sin(2 * pi * xx) + cos(yy / 2 * pi), +1.0)",
+                "max(3.33, min(sqrt(1 - sin(2 * xx) + cos(pi / yy) / 3), 1.11))",
+                "if(avg(xx,yy) <= xx + yy, xx - yy, xx * yy) + 2 * pi / xx",
+                "1.1xx^1 + 2.2yy^2 - 3.3xx^3 + 4.4yy^4 - 5.5xx^5 + 6.6yy^6 - 7.7xx^27 + 8.8yy^55",
+                "(1.1*(2.2*(3.3*(4.4*(5.5*(6.6*(7.7*(8.8*(9.9+x)))))))))",
+                "(((((((((x+9.9)*8.8)*7.7)*6.6)*5.5)*4.4)*3.3)*2.2)*1.1)",
+                "(x + y) * z", "x + (y * z)", "(x + y) * 7", "x + (y * 7)",
+                "(x + 7) * y", "x + (7 * y)", "(7 + x) * y", "7 + (x * y)",
+                "(2 + x) * 3", "2 + (x * 3)", "(2 + 3) * x", "2 + (3 * x)",
+                "(x + 2) * 3", "x + (2 * 3)",
+                "(x + y) * (z / w)", "(x + y) * (z / 7)", "(x + y) * (7 / z)", "(x + 7) * (y / z)",
+                "(7 + x) * (y / z)", "(2 + x) * (y / z)", "(x + 2) * (y / 3)", "(2 + x) * (y / 3)",
+                "(x + 2) * (3 / y)", "x + (y * (z / w))", "x + (y * (z / 7))", "x + (y * (7 / z))",
+                "x + (7 * (y / z))", "7 + (x * (y / z))", "2 + (x * (3 / y))", "x + (2 * (y / 4))",
+                "2 + (x * (y / 3))", "x + (2 * (3 / y))",
+                "x + ((y * z) / w)", "x + ((y * z) / 7)", "x + ((y * 7) / z)", "x + ((7 * y) / z)",
+                "7 + ((y * z) / w)", "2 + ((x * 3) / y)", "x + ((2 * y) / 3)", "2 + ((x * y) / 3)",
+                "x + ((2 * 3) / y)", "(((x + y) * z) / w)",
+                "(((x + y) * z) / 7)", "(((x + y) * 7) / z)", "(((x + 7) * y) / z)", "(((7 + x) * y) / z)",
+                "(((2 + x) * 3) / y)", "(((x + 2) * y) / 3)", "(((2 + x) * y) / 3)", "(((x + 2) * 3) / y)",
+                "((x + (y * z)) / w)", "((x + (y * z)) / 7)", "((x + (y * 7)) / y)", "((x + (7 * y)) / z)",
+                "((7 + (x * y)) / z)", "((2 + (x * 3)) / y)", "((x + (2 * y)) / 3)", "((2 + (x * y)) / 3)",
+                "((x + (2 * 3)) / y)",
+                "(xx + yy) * zz", "xx + (yy * zz)",
+                "(xx + yy) * 7", "xx + (yy * 7)",
+                "(xx + 7) * yy", "xx + (7 * yy)",
+                "(7 + xx) * yy", "7 + (xx * yy)",
+                "(2 + x) * 3", "2 + (x * 3)",
+                "(2 + 3) * x", "2 + (3 * x)",
+                "(x + 2) * 3", "x + (2 * 3)",
+                "(xx + yy) * (zz / ww)", "(xx + yy) * (zz / 7)",
+                "(xx + yy) * (7 / zz)", "(xx + 7) * (yy / zz)",
+                "(7 + xx) * (yy / zz)", "(2 + xx) * (yy / zz)",
+                "(xx + 2) * (yy / 3)", "(2 + xx) * (yy / 3)",
+                "(xx + 2) * (3 / yy)", "xx + (yy * (zz / ww))",
+                "xx + (yy * (zz / 7))", "xx + (yy * (7 / zz))",
+                "xx + (7 * (yy / zz))", "7 + (xx * (yy / zz))",
+                "2 + (xx * (3 / yy))", "xx + (2 * (yy / 4))",
+                "2 + (xx * (yy / 3))", "xx + (2 * (3 / yy))",
+                "xx + ((yy * zz) / ww)", "xx + ((yy * zz) / 7)",
+                "xx + ((yy * 7) / zz)", "xx + ((7 * yy) / zz)",
+                "7 + ((yy * zz) / ww)", "2 + ((xx * 3) / yy)",
+                "xx + ((2 * yy) / 3)", "2 + ((xx * yy) / 3)",
+                "xx + ((2 * 3) / yy)", "(((xx + yy) * zz) / ww)",
+                "(((xx + yy) * zz) / 7)", "(((xx + yy) * 7) / zz)",
+                "(((xx + 7) * yy) / zz)", "(((7 + xx) * yy) / zz)",
+                "(((2 + xx) * 3) / yy)", "(((xx + 2) * yy) / 3)",
+                "(((2 + xx) * yy) / 3)", "(((xx + 2) * 3) / yy)",
+                "((xx + (yy * zz)) / ww)", "((xx + (yy * zz)) / 7)",
+                "((xx + (yy * 7)) / yy)", "((xx + (7 * yy)) / zz)",
+                "((7 + (xx * yy)) / zz)", "((2 + (xx * 3)) / yy)",
+                "((xx + (2 * yy)) / 3)", "((2 + (xx * yy)) / 3)",
+                "((xx + (2 * 3)) / yy)"
+             };
+
+      static const std::size_t expression_list_size = sizeof(expression_list) / sizeof(std::string);
+
+      T  x = T(0);
+      T  y = T(0);
+      T  z = T(0);
+      T  w = T(0);
+      T xx = T(0);
+      T yy = T(0);
+      T zz = T(0);
+      T ww = T(0);
+
+      exprtk::symbol_table<T> symbol_table;
+      symbol_table.add_constants();
+      symbol_table.add_variable( "x", x);
+      symbol_table.add_variable( "y", y);
+      symbol_table.add_variable( "z", z);
+      symbol_table.add_variable( "w", w);
+      symbol_table.add_variable("xx",xx);
+      symbol_table.add_variable("yy",yy);
+      symbol_table.add_variable("zz",zz);
+      symbol_table.add_variable("ww",ww);
+
+      typedef typename std::deque<exprtk::expression<T> > expr_list_t;
+      expr_list_t expr_list;
+
+      const std::size_t rounds = 50;
+
+      {
+         for (std::size_t r = 0; r < rounds; ++r)
+         {
+            expr_list.clear();
+            exprtk::parser<T> parser;
+
+            for (std::size_t i = 0; i < expression_list_size; ++i)
+            {
+               exprtk::expression<T> expression;
+               expression.register_symbol_table(symbol_table);
+
+               if (!parser.compile(expression_list[i],expression))
+               {
+                  return false;
+               }
+
+               expr_list.push_back(expression);
+            }
+         }
+      }
+
+      struct execute
+      {
+         static inline T process(T& x, T& y, expression<T>& expression)
+         {
+            static const T lower_bound = T(-20);
+            static const T upper_bound = T(+20);
+            static const T delta       = T(0.1);
+
+            T total = T(0);
+
+            for (x = lower_bound; x <= upper_bound; x += delta)
+            {
+               for (y = lower_bound; y <= upper_bound; y += delta)
+               {
+                  total += expression.value();
+               }
+            }
+
+            return total;
+         }
+      };
+
+      for (std::size_t i = 0; i < expr_list.size(); ++i)
+      {
+         execute::process( x,  y, expr_list[i]);
+         execute::process(xx, yy, expr_list[i]);
+      }
+
+      {
+         for (std::size_t i = 0; i < 10000; ++i)
+         {
+            const T v = T(123.456 + i);
+
+            if (details::is_true(details::numeric::nequal(details::numeric::fast_exp<T, 1>::result(v),details::numeric::pow(v,T( 1)))))
+               return false;
+
+            #define else_stmt(N)                                                                                                           \
+            else if (details::is_true(details::numeric::nequal(details::numeric::fast_exp<T,N>::result(v),details::numeric::pow(v,T(N))))) \
+               return false;                                                                                                               \
+
+            else_stmt( 2) else_stmt( 3) else_stmt( 4) else_stmt( 5)
+            else_stmt( 6) else_stmt( 7) else_stmt( 8) else_stmt( 9)
+            else_stmt(10) else_stmt(11) else_stmt(12) else_stmt(13)
+            else_stmt(14) else_stmt(15) else_stmt(16) else_stmt(17)
+            else_stmt(18) else_stmt(19) else_stmt(20) else_stmt(21)
+            else_stmt(22) else_stmt(23) else_stmt(24) else_stmt(25)
+            else_stmt(26) else_stmt(27) else_stmt(28) else_stmt(29)
+            else_stmt(30) else_stmt(31) else_stmt(32) else_stmt(33)
+            else_stmt(34) else_stmt(35) else_stmt(36) else_stmt(37)
+            else_stmt(38) else_stmt(39) else_stmt(40) else_stmt(41)
+            else_stmt(42) else_stmt(43) else_stmt(44) else_stmt(45)
+            else_stmt(46) else_stmt(47) else_stmt(48) else_stmt(49)
+            else_stmt(50) else_stmt(51) else_stmt(52) else_stmt(53)
+            else_stmt(54) else_stmt(55) else_stmt(56) else_stmt(57)
+            else_stmt(58) else_stmt(59) else_stmt(60) else_stmt(61)
+         }
+      }
+
+      return true;
+   }
+}
+
+#if defined(_WIN32) || defined(__WIN32__) || defined(WIN32)
+#   ifndef NOMINMAX
+#      define NOMINMAX
+#   endif
+#   ifndef WIN32_LEAN_AND_MEAN
+#      define WIN32_LEAN_AND_MEAN
+#   endif
+#   include <windows.h>
+#   include <ctime>
+#else
+#   include <ctime>
+#   include <sys/time.h>
+#   include <sys/types.h>
+#endif
+
+namespace exprtk
+{
+   class timer
+   {
+   public:
+
+      #if defined(_WIN32) || defined(__WIN32__) || defined(WIN32)
+      timer()
+      : in_use_(false)
+      {
+         QueryPerformanceFrequency(&clock_frequency_);
+      }
+
+      inline void start()
+      {
+         in_use_ = true;
+         QueryPerformanceCounter(&start_time_);
+      }
+
+      inline void stop()
+      {
+         QueryPerformanceCounter(&stop_time_);
+         in_use_ = false;
+      }
+
+      inline double time() const
+      {
+         return (1.0 * (stop_time_.QuadPart - start_time_.QuadPart)) / (1.0 * clock_frequency_.QuadPart);
+      }
+
+      #else
+
+      timer()
+      : in_use_(false)
+      {
+         start_time_.tv_sec  = 0;
+         start_time_.tv_usec = 0;
+         stop_time_.tv_sec   = 0;
+         stop_time_.tv_usec  = 0;
+      }
+
+      inline void start()
+      {
+         in_use_ = true;
+         gettimeofday(&start_time_,0);
+      }
+
+      inline void stop()
+      {
+         gettimeofday(&stop_time_, 0);
+         in_use_ = false;
+      }
+
+      inline unsigned long long int usec_time() const
+      {
+         if (!in_use_)
+         {
+            if (stop_time_.tv_sec >= start_time_.tv_sec)
+            {
+               return 1000000LLU * static_cast<details::_uint64_t>(stop_time_.tv_sec  - start_time_.tv_sec ) +
+                                   static_cast<details::_uint64_t>(stop_time_.tv_usec - start_time_.tv_usec) ;
+            }
+            else
+               return std::numeric_limits<details::_uint64_t>::max();
+         }
+         else
+            return std::numeric_limits<details::_uint64_t>::max();
+      }
+
+      inline double time() const
+      {
+         return usec_time() * 0.000001;
+      }
+
+      #endif
+
+      inline bool in_use() const
+      {
+         return in_use_;
+      }
+
+   private:
+
+      bool in_use_;
+
+      #if defined(_WIN32) || defined(__WIN32__) || defined(WIN32)
+         LARGE_INTEGER start_time_;
+         LARGE_INTEGER stop_time_;
+         LARGE_INTEGER clock_frequency_;
+      #else
+         struct timeval start_time_;
+         struct timeval stop_time_;
+      #endif
+   };
+
+} // namespace exprtk
+
+#ifndef exprtk_disable_rtl_io
+namespace exprtk
+{
+   namespace rtl { namespace io { namespace details
+   {
+      template <typename T>
+      inline void print_type(const std::string& fmt,
+                             const T v,
+                             exprtk::details::numeric::details::real_type_tag)
+      {
+         printf(fmt.c_str(),v);
+      }
+
+      template <typename T>
+      struct print_impl
+      {
+         typedef typename igeneric_function<T>::generic_type generic_type;
+         typedef typename igeneric_function<T>::parameter_list_t parameter_list_t;
+         typedef typename generic_type::scalar_view scalar_t;
+         typedef typename generic_type::vector_view vector_t;
+         typedef typename generic_type::string_view string_t;
+         typedef typename exprtk::details::numeric::details::number_type<T>::type num_type;
+
+         static void process(const std::string& scalar_format, parameter_list_t parameters)
+         {
+            for (std::size_t i = 0; i < parameters.size(); ++i)
+            {
+               generic_type& gt = parameters[i];
+
+               switch (gt.type)
+               {
+                  case generic_type::e_scalar : print(scalar_format,scalar_t(gt));
+                                                break;
+
+                  case generic_type::e_vector : print(scalar_format,vector_t(gt));
+                                                break;
+
+                  case generic_type::e_string : print(string_t(gt));
+                                                break;
+
+                  default                     : continue;
+               }
+            }
+         }
+
+         static inline void print(const std::string& scalar_format, const scalar_t& s)
+         {
+            print_type(scalar_format,s(),num_type());
+         }
+
+         static inline void print(const std::string& scalar_format, const vector_t& v)
+         {
+            for (std::size_t i = 0; i < v.size(); ++i)
+            {
+               print_type(scalar_format,v[i],num_type());
+
+               if ((i + 1) < v.size())
+                  printf(" ");
+            }
+         }
+
+         static inline void print(const string_t& s)
+         {
+            printf("%s",to_str(s).c_str());
+         }
+      };
+
+   } // namespace exprtk::rtl::io::details
+
+   template <typename T>
+   struct print : public exprtk::igeneric_function<T>
+   {
+      typedef typename igeneric_function<T>::parameter_list_t parameter_list_t;
+
+      using exprtk::igeneric_function<T>::operator();
+
+      print(const std::string& scalar_format = "%10.5f")
+      : scalar_format_(scalar_format)
+      {
+         exprtk::enable_zero_parameters(*this);
+      }
+
+      inline T operator() (parameter_list_t parameters)
+      {
+         details::print_impl<T>::process(scalar_format_,parameters);
+         return T(0);
+      }
+
+      std::string scalar_format_;
+   };
+
+   template <typename T>
+   struct println : public exprtk::igeneric_function<T>
+   {
+      typedef typename igeneric_function<T>::parameter_list_t parameter_list_t;
+
+      using exprtk::igeneric_function<T>::operator();
+
+      println(const std::string& scalar_format = "%10.5f")
+      : scalar_format_(scalar_format)
+      {
+         exprtk::enable_zero_parameters(*this);
+      }
+
+      inline T operator() (parameter_list_t parameters)
+      {
+         details::print_impl<T>::process(scalar_format_,parameters);
+         printf("\n");
+         return T(0);
+      }
+
+      std::string scalar_format_;
+   };
+
+   template <typename T>
+   struct package
+   {
+      print  <T> p;
+      println<T> pl;
+
+      bool register_package(exprtk::symbol_table<T>& symtab)
+      {
+         #define exprtk_register_function(FunctionName,FunctionType)              \
+         if (!symtab.add_function(FunctionName,FunctionType))                     \
+         {                                                                        \
+            exprtk_debug((                                                        \
+              "exprtk::rtl::io::register_package - Failed to add function: %s\n", \
+              FunctionName));                                                     \
+            return false;                                                         \
+         }                                                                        \
+
+         exprtk_register_function("print"  ,  p)
+         exprtk_register_function("println", pl)
+         #undef exprtk_register_function
+
+         return true;
+      }
+   };
+
+   } // namespace exprtk::rtl::io
+   } // namespace exprtk::rtl
+}    // namespace exprtk
+#endif
+
+#ifndef exprtk_disable_rtl_io_file
+#include <fstream>
+namespace exprtk
+{
+   namespace rtl { namespace io { namespace file { namespace details
+   {
+      enum file_mode
+      {
+         e_error = 0,
+         e_read  = 1,
+         e_write = 2,
+         e_rdwrt = 4
+      };
+
+      struct file_descriptor
+      {
+         file_descriptor(const std::string& fname, const std::string& access)
+         : stream_ptr(0),
+           mode(get_file_mode(access)),
+           file_name(fname)
+         {}
+
+         void*       stream_ptr;
+         file_mode   mode;
+         std::string file_name;
+
+         bool open()
+         {
+            if (e_read == mode)
+            {
+               std::ifstream* stream = new std::ifstream(file_name.c_str(),std::ios::binary);
+
+               if (!(*stream))
+               {
+                  file_name.clear();
+                  delete stream;
+
+                  return false;
+               }
+               else
+                  stream_ptr = stream;
+
+               return true;
+            }
+            else if (e_write == mode)
+            {
+               std::ofstream* stream = new std::ofstream(file_name.c_str(),std::ios::binary);
+
+               if (!(*stream))
+               {
+                  file_name.clear();
+                  delete stream;
+
+                  return false;
+               }
+               else
+                  stream_ptr = stream;
+
+               return true;
+            }
+            else if (e_rdwrt == mode)
+            {
+               std::fstream* stream = new std::fstream(file_name.c_str(),std::ios::binary);
+
+               if (!(*stream))
+               {
+                  file_name.clear();
+                  delete stream;
+
+                  return false;
+               }
+               else
+                  stream_ptr = stream;
+
+               return true;
+            }
+            else
+               return false;
+         }
+
+         template <typename Stream, typename Ptr>
+         void close(Ptr& p)
+         {
+            Stream* stream = reinterpret_cast<Stream*>(p);
+            stream->close();
+            delete stream;
+            p = reinterpret_cast<Ptr>(0);
+         }
+
+         bool close()
+         {
+            switch (mode)
+            {
+               case e_read  : close<std::ifstream>(stream_ptr);
+                              break;
+
+               case e_write : close<std::ofstream>(stream_ptr);
+                              break;
+
+               case e_rdwrt : close<std::fstream> (stream_ptr);
+                              break;
+
+               default      : return false;
+            }
+
+            return true;
+         }
+
+         template <typename View>
+         bool write(const View& view, const std::size_t amount, const std::size_t offset = 0)
+         {
+            switch (mode)
+            {
+               case e_write : reinterpret_cast<std::ofstream*>(stream_ptr)->
+                                 write(reinterpret_cast<const char*>(view.begin() + offset), amount * sizeof(typename View::value_t));
+                              break;
+
+               case e_rdwrt : reinterpret_cast<std::fstream*>(stream_ptr)->
+                                 write(reinterpret_cast<const char*>(view.begin() + offset) , amount * sizeof(typename View::value_t));
+                              break;
+
+               default      : return false;
+            }
+
+            return true;
+         }
+
+         template <typename View>
+         bool read(View& view, const std::size_t amount, const std::size_t offset = 0)
+         {
+            switch (mode)
+            {
+               case e_read  : reinterpret_cast<std::ifstream*>(stream_ptr)->
+                                 read(reinterpret_cast<char*>(view.begin() + offset), amount * sizeof(typename View::value_t));
+                              break;
+
+               case e_rdwrt : reinterpret_cast<std::fstream*>(stream_ptr)->
+                                 read(reinterpret_cast<char*>(view.begin() + offset) , amount * sizeof(typename View::value_t));
+                              break;
+
+               default      : return false;
+            }
+
+            return true;
+         }
+
+         bool getline(std::string& s)
+         {
+            switch (mode)
+            {
+               case e_read  : return (!!std::getline(*reinterpret_cast<std::ifstream*>(stream_ptr),s));
+               case e_rdwrt : return (!!std::getline(*reinterpret_cast<std::fstream* >(stream_ptr),s));
+               default      : return false;
+            }
+         }
+
+         bool eof() const
+         {
+            switch (mode)
+            {
+               case e_read  : return reinterpret_cast<std::ifstream*>(stream_ptr)->eof();
+               case e_write : return reinterpret_cast<std::ofstream*>(stream_ptr)->eof();
+               case e_rdwrt : return reinterpret_cast<std::fstream* >(stream_ptr)->eof();
+               default      : return true;
+            }
+         }
+
+         file_mode get_file_mode(const std::string& access) const
+         {
+            if (access.empty() || access.size() > 2)
+               return e_error;
+
+            std::size_t w_cnt = 0;
+            std::size_t r_cnt = 0;
+
+            for (std::size_t i = 0; i < access.size(); ++i)
+            {
+               switch (std::tolower(access[i]))
+               {
+                  case 'r' : r_cnt++; break;
+                  case 'w' : w_cnt++; break;
+                  default  : return e_error;
+               }
+            }
+
+            if ((0 == r_cnt) && (0 == w_cnt))
+               return e_error;
+            else if ((r_cnt > 1) || (w_cnt > 1))
+               return e_error;
+            else if ((1 == r_cnt) && (1 == w_cnt))
+               return e_rdwrt;
+            else if (1 == r_cnt)
+               return e_read;
+            else
+               return e_write;
+         }
+      };
+
+      template <typename T>
+      file_descriptor* make_handle(T v)
+      {
+         file_descriptor* fd = reinterpret_cast<file_descriptor*>(0);
+
+         std::memcpy(reinterpret_cast<char*>(&fd),
+                     reinterpret_cast<const char*>(&v),
+                     sizeof(fd));
+         return fd;
+      }
+
+      template <typename T>
+      void perform_check()
+      {
+         #ifdef _MSC_VER
+         #pragma warning(push)
+         #pragma warning(disable: 4127)
+         #endif
+         if (sizeof(T) < sizeof(void*))
+         {
+            throw std::runtime_error("exprtk::rtl::io::file - Error - pointer size larger than holder.");
+         }
+         #ifdef _MSC_VER
+         #pragma warning(pop)
+         #endif
+      }
+
+   } // namespace exprtk::rtl::io::file::details
+
+   template <typename T>
+   class open : public exprtk::igeneric_function<T>
+   {
+   public:
+
+      typedef typename exprtk::igeneric_function<T> igfun_t;
+      typedef typename igfun_t::parameter_list_t    parameter_list_t;
+      typedef typename igfun_t::generic_type        generic_type;
+      typedef typename generic_type::string_view    string_t;
+
+      using exprtk::igeneric_function<T>::operator();
+
+      open()
+      : exprtk::igeneric_function<T>("S|SS")
+      { details::perform_check<T>(); }
+
+      inline T operator() (const std::size_t& ps_index, parameter_list_t parameters)
+      {
+         std::string file_name = to_str(string_t(parameters[0]));
+         std::string access;
+
+         if (file_name.empty())
+            return T(0);
+
+         if (0 == ps_index)
+            access = "r";
+         else if (0 == string_t(parameters[1]).size())
+            return T(0);
+         else
+            access = to_str(string_t(parameters[1]));
+
+         details::file_descriptor* fd = new details::file_descriptor(file_name,access);
+
+         if (fd->open())
+         {
+            T t = T(0);
+
+            std::memcpy(reinterpret_cast<char*>(&t ),
+                        reinterpret_cast<char*>(&fd),
+                        sizeof(fd));
+            return t;
+         }
+         else
+         {
+            delete fd;
+            return T(0);
+         }
+      }
+   };
+
+   template <typename T>
+   struct close : public exprtk::ifunction<T>
+   {
+      using exprtk::ifunction<T>::operator();
+
+      close()
+      : exprtk::ifunction<T>(1)
+      { details::perform_check<T>(); }
+
+      inline T operator() (const T& v)
+      {
+         details::file_descriptor* fd = details::make_handle(v);
+
+         if (!fd->close())
+            return T(0);
+
+         delete fd;
+
+         return T(1);
+      }
+   };
+
+   template <typename T>
+   class write : public exprtk::igeneric_function<T>
+   {
+   public:
+
+      typedef typename exprtk::igeneric_function<T> igfun_t;
+      typedef typename igfun_t::parameter_list_t    parameter_list_t;
+      typedef typename igfun_t::generic_type        generic_type;
+      typedef typename generic_type::string_view    string_t;
+      typedef typename generic_type::scalar_view    scalar_t;
+      typedef typename generic_type::vector_view    vector_t;
+
+      using exprtk::igeneric_function<T>::operator();
+
+      write()
+      : igfun_t("TS|TST|TV|TVT")
+      { details::perform_check<T>(); }
+
+      inline T operator() (const std::size_t& ps_index, parameter_list_t parameters)
+      {
+         details::file_descriptor* fd = details::make_handle(scalar_t(parameters[0])());
+
+         std::size_t amount = 0;
+
+         switch (ps_index)
+         {
+            case 0  : {
+                         const string_t buffer(parameters[1]);
+                         amount = buffer.size();
+                         return T(fd->write(buffer, amount) ? 1 : 0);
+                      }
+
+            case 1  : {
+                         const string_t buffer(parameters[1]);
+                         amount = std::min(buffer.size(),
+                                           static_cast<std::size_t>(scalar_t(parameters[2])()));
+                         return T(fd->write(buffer, amount) ? 1 : 0);
+                      }
+
+            case 2  : {
+                         const vector_t vec(parameters[1]);
+                         amount = vec.size();
+                         return T(fd->write(vec, amount) ? 1 : 0);
+                      }
+
+            case 3  : {
+                         const vector_t vec(parameters[1]);
+                         amount = std::min(vec.size(),
+                                           static_cast<std::size_t>(scalar_t(parameters[2])()));
+                         return T(fd->write(vec, amount) ? 1 : 0);
+                      }
+         }
+
+         return T(0);
+      }
+   };
+
+   template <typename T>
+   class read : public exprtk::igeneric_function<T>
+   {
+   public:
+
+      typedef typename exprtk::igeneric_function<T> igfun_t;
+      typedef typename igfun_t::parameter_list_t    parameter_list_t;
+      typedef typename igfun_t::generic_type        generic_type;
+      typedef typename generic_type::string_view    string_t;
+      typedef typename generic_type::scalar_view    scalar_t;
+      typedef typename generic_type::vector_view    vector_t;
+
+      using exprtk::igeneric_function<T>::operator();
+
+      read()
+      : igfun_t("TS|TST|TV|TVT")
+      { details::perform_check<T>(); }
+
+      inline T operator() (const std::size_t& ps_index, parameter_list_t parameters)
+      {
+         details::file_descriptor* fd = details::make_handle(scalar_t(parameters[0])());
+
+         std::size_t amount = 0;
+
+         switch (ps_index)
+         {
+            case 0  : {
+                         string_t buffer(parameters[1]);
+                         amount = buffer.size();
+                         return T(fd->read(buffer,amount) ? 1 : 0);
+                      }
+
+            case 1  : {
+                         string_t buffer(parameters[1]);
+                         amount = std::min(buffer.size(),
+                                           static_cast<std::size_t>(scalar_t(parameters[2])()));
+                         return T(fd->read(buffer,amount) ? 1 : 0);
+                      }
+
+            case 2  : {
+                         vector_t vec(parameters[1]);
+                         amount = vec.size();
+                         return T(fd->read(vec,amount) ? 1 : 0);
+                      }
+
+            case 3  : {
+                         vector_t vec(parameters[1]);
+                         amount = std::min(vec.size(),
+                                           static_cast<std::size_t>(scalar_t(parameters[2])()));
+                         return T(fd->read(vec,amount) ? 1 : 0);
+                      }
+         }
+
+         return T(0);
+      }
+   };
+
+   template <typename T>
+   class getline : public exprtk::igeneric_function<T>
+   {
+   public:
+
+      typedef typename exprtk::igeneric_function<T> igfun_t;
+      typedef typename igfun_t::parameter_list_t    parameter_list_t;
+      typedef typename igfun_t::generic_type        generic_type;
+      typedef typename generic_type::string_view    string_t;
+      typedef typename generic_type::scalar_view    scalar_t;
+
+      using exprtk::igeneric_function<T>::operator();
+
+      getline()
+      : igfun_t("T",igfun_t::e_rtrn_string)
+      { details::perform_check<T>(); }
+
+      inline T operator() (std::string& result,
+                           parameter_list_t parameters)
+      {
+         details::file_descriptor* fd = details::make_handle(scalar_t(parameters[0])());
+         return T(fd->getline(result) ? 1 : 0);
+      }
+   };
+
+   template <typename T>
+   struct eof : public exprtk::ifunction<T>
+   {
+      using exprtk::ifunction<T>::operator();
+
+      eof()
+      : exprtk::ifunction<T>(1)
+      { details::perform_check<T>(); }
+
+      inline T operator() (const T& v)
+      {
+         details::file_descriptor* fd = details::make_handle(v);
+
+         return (fd->eof() ? T(1) : T(0));
+      }
+   };
+
+   template <typename T>
+   struct package
+   {
+      open   <T> o;
+      close  <T> c;
+      write  <T> w;
+      read   <T> r;
+      getline<T> g;
+      eof    <T> e;
+
+      bool register_package(exprtk::symbol_table<T>& symtab)
+      {
+         #define exprtk_register_function(FunctionName,FunctionType)                    \
+         if (!symtab.add_function(FunctionName,FunctionType))                           \
+         {                                                                              \
+            exprtk_debug((                                                              \
+              "exprtk::rtl::io::file::register_package - Failed to add function: %s\n", \
+              FunctionName));                                                           \
+            return false;                                                               \
+         }                                                                              \
+
+         exprtk_register_function("open"   ,o)
+         exprtk_register_function("close"  ,c)
+         exprtk_register_function("write"  ,w)
+         exprtk_register_function("read"   ,r)
+         exprtk_register_function("getline",g)
+         exprtk_register_function("eof"    ,e)
+         #undef exprtk_register_function
+
+         return true;
+      }
+   };
+
+   } // namespace exprtk::rtl::io::file
+   } // namespace exprtk::rtl::io
+   } // namespace exprtk::rtl
+}    // namespace exprtk
+#endif
+
+#ifndef exprtk_disable_rtl_vecops
+namespace exprtk
+{
+   namespace rtl { namespace vecops {
+
+   namespace helper
+   {
+      template <typename Vector>
+      inline bool invalid_range(const Vector& v, const std::size_t r0, const std::size_t r1)
+      {
+         if (r0 > (v.size() - 1))
+            return true;
+         else if (r1 > (v.size() - 1))
+            return true;
+         else if (r1 < r0)
+            return true;
+         else
+            return false;
+      }
+
+      template <typename T>
+      struct load_vector_range
+      {
+         typedef typename exprtk::igeneric_function<T> igfun_t;
+         typedef typename igfun_t::parameter_list_t    parameter_list_t;
+         typedef typename igfun_t::generic_type        generic_type;
+         typedef typename generic_type::scalar_view    scalar_t;
+         typedef typename generic_type::vector_view    vector_t;
+
+         static inline bool process(parameter_list_t& parameters,
+                                    std::size_t& r0, std::size_t& r1,
+                                    const std::size_t& r0_prmidx,
+                                    const std::size_t& r1_prmidx,
+                                    const std::size_t vec_idx = 0)
+         {
+            if (r0_prmidx >= parameters.size())
+               return false;
+
+            if (r1_prmidx >= parameters.size())
+               return false;
+
+            if (!scalar_t(parameters[r0_prmidx]).to_uint(r0))
+               return false;
+
+            if (!scalar_t(parameters[r1_prmidx]).to_uint(r1))
+               return false;
+
+            return !invalid_range(vector_t(parameters[vec_idx]), r0, r1);
+         }
+      };
+   }
+
+   namespace details
+   {
+      template <typename T>
+      inline void kahan_sum(T& sum, T& error, const T v)
+      {
+         const T x = v - error;
+         const T y = sum + x;
+         error = (y - sum) - x;
+         sum = y;
+      }
+
+   } // namespace exprtk::rtl::details
+
+   template <typename T>
+   class all_true : public exprtk::igeneric_function<T>
+   {
+   public:
+
+      typedef typename exprtk::igeneric_function<T> igfun_t;
+      typedef typename igfun_t::parameter_list_t    parameter_list_t;
+      typedef typename igfun_t::generic_type        generic_type;
+      typedef typename generic_type::vector_view    vector_t;
+
+      using exprtk::igeneric_function<T>::operator();
+
+      all_true()
+      : exprtk::igeneric_function<T>("V|VTT")
+        /*
+           Overloads:
+           0. V   - vector
+           1. VTT - vector, r0, r1
+        */
+      {}
+
+      inline T operator() (const std::size_t& ps_index, parameter_list_t parameters)
+      {
+         const vector_t vec(parameters[0]);
+
+         std::size_t r0 = 0;
+         std::size_t r1 = vec.size() - 1;
+
+         if (
+              (1 == ps_index) &&
+              !helper::load_vector_range<T>::process(parameters, r0, r1, 1, 2, 0)
+            )
+            return std::numeric_limits<T>::quiet_NaN();
+
+         for (std::size_t i = r0; i <= r1; ++i)
+         {
+            if (vec[i] == T(0))
+            {
+               return T(0);
+            }
+         }
+
+         return T(1);
+      }
+   };
+
+   template <typename T>
+   class all_false : public exprtk::igeneric_function<T>
+   {
+   public:
+
+      typedef typename exprtk::igeneric_function<T> igfun_t;
+      typedef typename igfun_t::parameter_list_t    parameter_list_t;
+      typedef typename igfun_t::generic_type        generic_type;
+      typedef typename generic_type::vector_view    vector_t;
+
+      using exprtk::igeneric_function<T>::operator();
+
+      all_false()
+      : exprtk::igeneric_function<T>("V|VTT")
+        /*
+           Overloads:
+           0. V   - vector
+           1. VTT - vector, r0, r1
+        */
+      {}
+
+      inline T operator() (const std::size_t& ps_index, parameter_list_t parameters)
+      {
+         const vector_t vec(parameters[0]);
+
+         std::size_t r0 = 0;
+         std::size_t r1 = vec.size() - 1;
+
+         if (
+              (1 == ps_index) &&
+              !helper::load_vector_range<T>::process(parameters, r0, r1, 1, 2, 0)
+            )
+            return std::numeric_limits<T>::quiet_NaN();
+
+         for (std::size_t i = r0; i <= r1; ++i)
+         {
+            if (vec[i] != T(0))
+            {
+               return T(0);
+            }
+         }
+
+         return T(1);
+      }
+   };
+
+   template <typename T>
+   class any_true : public exprtk::igeneric_function<T>
+   {
+   public:
+
+      typedef typename exprtk::igeneric_function<T> igfun_t;
+      typedef typename igfun_t::parameter_list_t    parameter_list_t;
+      typedef typename igfun_t::generic_type        generic_type;
+      typedef typename generic_type::vector_view    vector_t;
+
+      using exprtk::igeneric_function<T>::operator();
+
+      any_true()
+      : exprtk::igeneric_function<T>("V|VTT")
+        /*
+           Overloads:
+           0. V   - vector
+           1. VTT - vector, r0, r1
+        */
+      {}
+
+      inline T operator() (const std::size_t& ps_index, parameter_list_t parameters)
+      {
+         const vector_t vec(parameters[0]);
+
+         std::size_t r0 = 0;
+         std::size_t r1 = vec.size() - 1;
+
+         if (
+              (1 == ps_index) &&
+              !helper::load_vector_range<T>::process(parameters, r0, r1, 1, 2, 0)
+            )
+            return std::numeric_limits<T>::quiet_NaN();
+
+         for (std::size_t i = r0; i <= r1; ++i)
+         {
+            if (vec[i] != T(0))
+            {
+               return T(1);
+            }
+         }
+
+         return T(0);
+      }
+   };
+
+   template <typename T>
+   class any_false : public exprtk::igeneric_function<T>
+   {
+   public:
+
+      typedef typename exprtk::igeneric_function<T> igfun_t;
+      typedef typename igfun_t::parameter_list_t    parameter_list_t;
+      typedef typename igfun_t::generic_type        generic_type;
+      typedef typename generic_type::vector_view    vector_t;
+
+      using exprtk::igeneric_function<T>::operator();
+
+      any_false()
+      : exprtk::igeneric_function<T>("V|VTT")
+        /*
+           Overloads:
+           0. V   - vector
+           1. VTT - vector, r0, r1
+        */
+      {}
+
+      inline T operator() (const std::size_t& ps_index, parameter_list_t parameters)
+      {
+         const vector_t vec(parameters[0]);
+
+         std::size_t r0 = 0;
+         std::size_t r1 = vec.size() - 1;
+
+         if (
+              (1 == ps_index) &&
+              !helper::load_vector_range<T>::process(parameters, r0, r1, 1, 2, 0)
+            )
+            return std::numeric_limits<T>::quiet_NaN();
+
+         for (std::size_t i = r0; i <= r1; ++i)
+         {
+            if (vec[i] == T(0))
+            {
+               return T(1);
+            }
+         }
+
+         return T(0);
+      }
+   };
+
+   template <typename T>
+   class count : public exprtk::igeneric_function<T>
+   {
+   public:
+
+      typedef typename exprtk::igeneric_function<T> igfun_t;
+      typedef typename igfun_t::parameter_list_t    parameter_list_t;
+      typedef typename igfun_t::generic_type        generic_type;
+      typedef typename generic_type::vector_view    vector_t;
+
+      using exprtk::igeneric_function<T>::operator();
+
+      count()
+      : exprtk::igeneric_function<T>("V|VTT")
+        /*
+           Overloads:
+           0. V   - vector
+           1. VTT - vector, r0, r1
+        */
+      {}
+
+      inline T operator() (const std::size_t& ps_index, parameter_list_t parameters)
+      {
+         const vector_t vec(parameters[0]);
+
+         std::size_t r0 = 0;
+         std::size_t r1 = vec.size() - 1;
+
+         if (
+              (1 == ps_index) &&
+              !helper::load_vector_range<T>::process(parameters, r0, r1, 1, 2, 0)
+            )
+            return std::numeric_limits<T>::quiet_NaN();
+
+         std::size_t cnt = 0;
+
+         for (std::size_t i = r0; i <= r1; ++i)
+         {
+            if (vec[i] != T(0)) ++cnt;
+         }
+
+         return T(cnt);
+      }
+   };
+
+   template <typename T>
+   class copy : public exprtk::igeneric_function<T>
+   {
+   public:
+
+      typedef typename exprtk::igeneric_function<T> igfun_t;
+      typedef typename igfun_t::parameter_list_t    parameter_list_t;
+      typedef typename igfun_t::generic_type        generic_type;
+      typedef typename generic_type::scalar_view    scalar_t;
+      typedef typename generic_type::vector_view    vector_t;
+
+      using exprtk::igeneric_function<T>::operator();
+
+      copy()
+      : exprtk::igeneric_function<T>("VV|VTTVTT")
+        /*
+           Overloads:
+           0. VV     - x(vector), y(vector)
+           1. VTTVTT - x(vector), xr0, xr1, y(vector), yr0, yr1,
+        */
+      {}
+
+      inline T operator() (const std::size_t& ps_index, parameter_list_t parameters)
+      {
+         const vector_t x(parameters[0]);
+               vector_t y(parameters[(0 == ps_index) ? 1 : 3]);
+
+         std::size_t xr0 = 0;
+         std::size_t xr1 = x.size() - 1;
+
+         std::size_t yr0 = 0;
+         std::size_t yr1 = y.size() - 1;
+
+         if (1 == ps_index)
+         {
+            if (
+                 !helper::load_vector_range<T>::process(parameters, xr0, xr1, 1, 2, 0) ||
+                 !helper::load_vector_range<T>::process(parameters, yr0, yr1, 4, 5, 3)
+               )
+               return T(0);
+         }
+
+         const std::size_t n = std::min(xr1 - xr0 + 1, yr1 - yr0 + 1);
+
+         std::copy(x.begin() + xr0, x.begin() + xr0 + n, y.begin() + yr0);
+
+         return T(n);
+      }
+   };
+
+   template <typename T>
+   class rol : public exprtk::igeneric_function<T>
+   {
+   public:
+
+      typedef typename exprtk::igeneric_function<T> igfun_t;
+      typedef typename igfun_t::parameter_list_t    parameter_list_t;
+      typedef typename igfun_t::generic_type        generic_type;
+      typedef typename generic_type::scalar_view    scalar_t;
+      typedef typename generic_type::vector_view    vector_t;
+
+      using exprtk::igeneric_function<T>::operator();
+
+      rol()
+      : exprtk::igeneric_function<T>("VT|VTTT")
+        /*
+           Overloads:
+           0. VT   - vector, N
+           1. VTTT - vector, N, r0, r1
+        */
+      {}
+
+      inline T operator() (const std::size_t& ps_index, parameter_list_t parameters)
+      {
+         vector_t vec(parameters[0]);
+
+         std::size_t n  = 0;
+         std::size_t r0 = 0;
+         std::size_t r1 = vec.size() - 1;
+
+         if (!scalar_t(parameters[1]).to_uint(n))
+            return T(0);
+
+         if (
+              (1 == ps_index) &&
+              !helper::load_vector_range<T>::process(parameters, r0, r1, 2, 3, 0)
+            )
+            return T(0);
+
+         std::size_t dist  = r1 - r0 + 1;
+         std::size_t shift = n % dist;
+
+         std::rotate(vec.begin() + r0, vec.begin() + r0 + shift, vec.begin() + r1 + 1);
+
+         return T(1);
+      }
+   };
+
+   template <typename T>
+   class ror : public exprtk::igeneric_function<T>
+   {
+   public:
+
+      typedef typename exprtk::igeneric_function<T> igfun_t;
+      typedef typename igfun_t::parameter_list_t    parameter_list_t;
+      typedef typename igfun_t::generic_type        generic_type;
+      typedef typename generic_type::scalar_view    scalar_t;
+      typedef typename generic_type::vector_view    vector_t;
+
+      using exprtk::igeneric_function<T>::operator();
+
+      ror()
+      : exprtk::igeneric_function<T>("VT|VTTT")
+        /*
+           Overloads:
+           0. VT   - vector, N
+           1. VTTT - vector, N, r0, r1
+        */
+      {}
+
+      inline T operator() (const std::size_t& ps_index, parameter_list_t parameters)
+      {
+         vector_t vec(parameters[0]);
+
+         std::size_t n  = 0;
+         std::size_t r0 = 0;
+         std::size_t r1 = vec.size() - 1;
+
+         if (!scalar_t(parameters[1]).to_uint(n))
+            return T(0);
+
+         if (
+              (1 == ps_index) &&
+              !helper::load_vector_range<T>::process(parameters, r0, r1, 2, 3, 0)
+            )
+            return T(0);
+
+         std::size_t dist  = r1 - r0 + 1;
+         std::size_t shift = (dist - (n % dist)) % dist;
+
+         std::rotate(vec.begin() + r0, vec.begin() + r0 + shift, vec.begin() + r1 + 1);
+
+         return T(1);
+      }
+   };
+
+   template <typename T>
+   class shift_left : public exprtk::igeneric_function<T>
+   {
+   public:
+
+      typedef typename exprtk::igeneric_function<T> igfun_t;
+      typedef typename igfun_t::parameter_list_t    parameter_list_t;
+      typedef typename igfun_t::generic_type        generic_type;
+      typedef typename generic_type::scalar_view    scalar_t;
+      typedef typename generic_type::vector_view    vector_t;
+
+      using exprtk::igeneric_function<T>::operator();
+
+      shift_left()
+      : exprtk::igeneric_function<T>("VT|VTTT")
+        /*
+           Overloads:
+           0. VT   - vector, N
+           1. VTTT - vector, N, r0, r1
+        */
+      {}
+
+      inline T operator() (const std::size_t& ps_index, parameter_list_t parameters)
+      {
+         vector_t vec(parameters[0]);
+
+         std::size_t n  = 0;
+         std::size_t r0 = 0;
+         std::size_t r1 = vec.size() - 1;
+
+         if (!scalar_t(parameters[1]).to_uint(n))
+            return T(0);
+
+         if (
+              (1 == ps_index) &&
+              !helper::load_vector_range<T>::process(parameters, r0, r1, 2, 3, 0)
+            )
+            return T(0);
+
+         std::size_t dist  = r1 - r0 + 1;
+
+         if (n > dist)
+            return T(0);
+
+         std::rotate(vec.begin() + r0, vec.begin() + r0 + n, vec.begin() + r1 + 1);
+
+         for (std::size_t i = r1 - n + 1; i <= r1; ++i)
+         {
+            vec[i] = T(0);
+         }
+
+         return T(1);
+      }
+   };
+
+   template <typename T>
+   class shift_right : public exprtk::igeneric_function<T>
+   {
+   public:
+
+      typedef typename exprtk::igeneric_function<T> igfun_t;
+      typedef typename igfun_t::parameter_list_t    parameter_list_t;
+      typedef typename igfun_t::generic_type        generic_type;
+      typedef typename generic_type::scalar_view    scalar_t;
+      typedef typename generic_type::vector_view    vector_t;
+
+      using exprtk::igeneric_function<T>::operator();
+
+      shift_right()
+      : exprtk::igeneric_function<T>("VT|VTTT")
+        /*
+           Overloads:
+           0. VT   - vector, N
+           1. VTTT - vector, N, r0, r1
+        */
+      {}
+
+      inline T operator() (const std::size_t& ps_index, parameter_list_t parameters)
+      {
+         vector_t vec(parameters[0]);
+
+         std::size_t n  = 0;
+         std::size_t r0 = 0;
+         std::size_t r1 = vec.size() - 1;
+
+         if (!scalar_t(parameters[1]).to_uint(n))
+            return T(0);
+
+         if (
+              (1 == ps_index) &&
+              !helper::load_vector_range<T>::process(parameters, r0, r1, 2, 3, 0)
+            )
+            return T(0);
+
+         std::size_t dist  = r1 - r0 + 1;
+
+         if (n > dist)
+            return T(0);
+
+         std::size_t shift = (dist - (n % dist)) % dist;
+
+         std::rotate(vec.begin() + r0, vec.begin() + r0 + shift, vec.begin() + r1 + 1);
+
+         for (std::size_t i = r0; i < r0 + n; ++i)
+         {
+            vec[i] = T(0);
+         }
+
+         return T(1);
+      }
+   };
+
+   template <typename T>
+   class sort : public exprtk::igeneric_function<T>
+   {
+   public:
+
+      typedef typename exprtk::igeneric_function<T> igfun_t;
+      typedef typename igfun_t::parameter_list_t    parameter_list_t;
+      typedef typename igfun_t::generic_type        generic_type;
+      typedef typename generic_type::string_view    string_t;
+      typedef typename generic_type::vector_view    vector_t;
+
+      using exprtk::igeneric_function<T>::operator();
+
+      sort()
+      : exprtk::igeneric_function<T>("V|VTT|VS|VSTT")
+        /*
+           Overloads:
+           0. V    - vector
+           1. VTT  - vector, r0, r1
+           2. VS   - vector, string
+           3. VSTT - vector, string, r0, r1
+        */
+      {}
+
+      inline T operator() (const std::size_t& ps_index, parameter_list_t parameters)
+      {
+         vector_t vec(parameters[0]);
+
+         std::size_t r0 = 0;
+         std::size_t r1 = vec.size() - 1;
+
+         if ((1 == ps_index) && !helper::load_vector_range<T>::process(parameters, r0, r1, 1, 2, 0))
+            return T(0);
+         if ((3 == ps_index) && !helper::load_vector_range<T>::process(parameters, r0, r1, 2, 3, 0))
+            return T(0);
+
+         bool ascending = true;
+
+         if ((2 == ps_index) || (3 == ps_index))
+         {
+            if (exprtk::details::imatch(to_str(string_t(parameters[1])),"ascending"))
+               ascending = true;
+            else if (exprtk::details::imatch(to_str(string_t(parameters[1])),"descending"))
+               ascending = false;
+            else
+               return T(0);
+         }
+
+         if (ascending)
+            std::sort(vec.begin() + r0, vec.begin() + r1 + 1, std::less<T>   ());
+         else
+            std::sort(vec.begin() + r0, vec.begin() + r1 + 1, std::greater<T>());
+
+         return T(1);
+      }
+   };
+
+   template <typename T>
+   class nthelement : public exprtk::igeneric_function<T>
+   {
+   public:
+
+      typedef typename exprtk::igeneric_function<T> igfun_t;
+      typedef typename igfun_t::parameter_list_t    parameter_list_t;
+      typedef typename igfun_t::generic_type        generic_type;
+      typedef typename generic_type::scalar_view    scalar_t;
+      typedef typename generic_type::vector_view    vector_t;
+
+      using exprtk::igeneric_function<T>::operator();
+
+      nthelement()
+      : exprtk::igeneric_function<T>("VT|VTTT")
+        /*
+           Overloads:
+           0. VT   - vector, nth-element
+           1. VTTT - vector, nth-element, r0, r1
+        */
+      {}
+
+      inline T operator() (const std::size_t& ps_index, parameter_list_t parameters)
+      {
+         vector_t vec(parameters[0]);
+
+         std::size_t n  = 0;
+         std::size_t r0 = 0;
+         std::size_t r1 = vec.size() - 1;
+
+         if (!scalar_t(parameters[1]).to_uint(n))
+            return T(0);
+
+         if ((1 == ps_index) && !helper::load_vector_range<T>::process(parameters, r0, r1, 2, 3, 0))
+            return std::numeric_limits<T>::quiet_NaN();
+
+         std::nth_element(vec.begin() + r0, vec.begin() + r0 + n , vec.begin() + r1 + 1);
+
+         return T(1);
+      }
+   };
+
+   template <typename T>
+   class iota : public exprtk::igeneric_function<T>
+   {
+   public:
+
+      typedef typename exprtk::igeneric_function<T> igfun_t;
+      typedef typename igfun_t::parameter_list_t    parameter_list_t;
+      typedef typename igfun_t::generic_type        generic_type;
+      typedef typename generic_type::scalar_view    scalar_t;
+      typedef typename generic_type::vector_view    vector_t;
+
+      using exprtk::igeneric_function<T>::operator();
+
+      iota()
+      : exprtk::igeneric_function<T>("VT|VTT|VTTT|VTTTT")
+        /*
+           Overloads:
+           0. VT    - vector, increment
+           1. VTT   - vector, increment, base
+           2. VTTTT - vector, increment, r0, r1
+           3. VTTTT - vector, increment, base, r0, r1
+        */
+      {}
+
+      inline T operator() (const std::size_t& ps_index, parameter_list_t parameters)
+      {
+         vector_t vec(parameters[0]);
+
+         T increment = scalar_t(parameters[1])();
+         T base      = ((1 == ps_index) || (3 == ps_index)) ? scalar_t(parameters[2])() : T(0);
+
+         std::size_t r0 = 0;
+         std::size_t r1 = vec.size() - 1;
+
+         if ((2 == ps_index) && !helper::load_vector_range<T>::process(parameters, r0, r1, 2, 3, 0))
+            return std::numeric_limits<T>::quiet_NaN();
+         else if ((3 == ps_index) && !helper::load_vector_range<T>::process(parameters, r0, r1, 3, 4, 0))
+            return std::numeric_limits<T>::quiet_NaN();
+         else
+         {
+            long long j = 0;
+
+            for (std::size_t i = r0; i <= r1; ++i, ++j)
+            {
+               vec[i] = base + (increment * j);
+            }
+         }
+
+         return T(1);
+      }
+   };
+
+   template <typename T>
+   class sumk : public exprtk::igeneric_function<T>
+   {
+   public:
+
+      typedef typename exprtk::igeneric_function<T> igfun_t;
+      typedef typename igfun_t::parameter_list_t    parameter_list_t;
+      typedef typename igfun_t::generic_type        generic_type;
+      typedef typename generic_type::vector_view    vector_t;
+
+      using exprtk::igeneric_function<T>::operator();
+
+      sumk()
+      : exprtk::igeneric_function<T>("V|VTT")
+        /*
+           Overloads:
+           0. V   - vector
+           1. VTT - vector, r0, r1
+        */
+      {}
+
+      inline T operator() (const std::size_t& ps_index, parameter_list_t parameters)
+      {
+         const vector_t vec(parameters[0]);
+
+         std::size_t r0 = 0;
+         std::size_t r1 = vec.size() - 1;
+
+         if ((1 == ps_index) && !helper::load_vector_range<T>::process(parameters, r0, r1, 1, 2, 0))
+            return std::numeric_limits<T>::quiet_NaN();
+
+         T result = T(0);
+         T error  = T(0);
+
+         for (std::size_t i = r0; i <= r1; ++i)
+         {
+            details::kahan_sum(result, error, vec[i]);
+         }
+
+         return result;
+      }
+   };
+
+   template <typename T>
+   class axpy : public exprtk::igeneric_function<T>
+   {
+   public:
+
+      typedef typename exprtk::igeneric_function<T> igfun_t;
+      typedef typename igfun_t::parameter_list_t    parameter_list_t;
+      typedef typename igfun_t::generic_type        generic_type;
+      typedef typename generic_type::scalar_view    scalar_t;
+      typedef typename generic_type::vector_view    vector_t;
+
+      using exprtk::igeneric_function<T>::operator();
+
+      axpy()
+      : exprtk::igeneric_function<T>("TVV|TVVTT")
+        /*
+           y <- ax + y
+           Overloads:
+           0. TVV   - a, x(vector), y(vector)
+           1. TVVTT - a, x(vector), y(vector), r0, r1
+        */
+      {}
+
+      inline T operator() (const std::size_t& ps_index, parameter_list_t parameters)
+      {
+         const vector_t x(parameters[1]);
+               vector_t y(parameters[2]);
+
+         std::size_t r0 = 0;
+         std::size_t r1 = std::min(x.size(),y.size()) - 1;
+
+         if ((1 == ps_index) && !helper::load_vector_range<T>::process(parameters, r0, r1, 3, 4, 1))
+            return std::numeric_limits<T>::quiet_NaN();
+         else if (helper::invalid_range(y, r0, r1))
+            return std::numeric_limits<T>::quiet_NaN();
+
+         const T a = scalar_t(parameters[0])();
+
+         for (std::size_t i = r0; i <= r1; ++i)
+         {
+            y[i] = (a * x[i]) + y[i];
+         }
+
+         return T(1);
+      }
+   };
+
+   template <typename T>
+   class axpby : public exprtk::igeneric_function<T>
+   {
+   public:
+
+      typedef typename exprtk::igeneric_function<T> igfun_t;
+      typedef typename igfun_t::parameter_list_t    parameter_list_t;
+      typedef typename igfun_t::generic_type        generic_type;
+      typedef typename generic_type::scalar_view    scalar_t;
+      typedef typename generic_type::vector_view    vector_t;
+
+      using exprtk::igeneric_function<T>::operator();
+
+      axpby()
+      : exprtk::igeneric_function<T>("TVTV|TVTVTT")
+        /*
+           y <- ax + by
+           Overloads:
+           0. TVTV   - a, x(vector), b, y(vector)
+           1. TVTVTT - a, x(vector), b, y(vector), r0, r1
+        */
+      {}
+
+      inline T operator() (const std::size_t& ps_index, parameter_list_t parameters)
+      {
+         const vector_t x(parameters[1]);
+               vector_t y(parameters[3]);
+
+         std::size_t r0 = 0;
+         std::size_t r1 = std::min(x.size(),y.size()) - 1;
+
+         if ((1 == ps_index) && !helper::load_vector_range<T>::process(parameters, r0, r1, 4, 5, 1))
+            return std::numeric_limits<T>::quiet_NaN();
+         else if (helper::invalid_range(y, r0, r1))
+            return std::numeric_limits<T>::quiet_NaN();
+
+         const T a = scalar_t(parameters[0])();
+         const T b = scalar_t(parameters[2])();
+
+         for (std::size_t i = r0; i <= r1; ++i)
+         {
+            y[i] = (a * x[i]) + (b * y[i]);
+         }
+
+         return T(1);
+      }
+   };
+
+   template <typename T>
+   class axpyz : public exprtk::igeneric_function<T>
+   {
+   public:
+
+      typedef typename exprtk::igeneric_function<T> igfun_t;
+      typedef typename igfun_t::parameter_list_t    parameter_list_t;
+      typedef typename igfun_t::generic_type        generic_type;
+      typedef typename generic_type::scalar_view    scalar_t;
+      typedef typename generic_type::vector_view    vector_t;
+
+      using exprtk::igeneric_function<T>::operator();
+
+      axpyz()
+      : exprtk::igeneric_function<T>("TVVV|TVVVTT")
+        /*
+           z <- ax + y
+           Overloads:
+           0. TVVV   - a, x(vector), y(vector), z(vector)
+           1. TVVVTT - a, x(vector), y(vector), z(vector), r0, r1
+        */
+      {}
+
+      inline T operator() (const std::size_t& ps_index, parameter_list_t parameters)
+      {
+         const vector_t x(parameters[1]);
+         const vector_t y(parameters[2]);
+               vector_t z(parameters[3]);
+
+         std::size_t r0 = 0;
+         std::size_t r1 = std::min(x.size(),y.size()) - 1;
+
+         if ((1 == ps_index) && !helper::load_vector_range<T>::process(parameters, r0, r1, 3, 4, 1))
+            return std::numeric_limits<T>::quiet_NaN();
+         else if (helper::invalid_range(y, r0, r1))
+            return std::numeric_limits<T>::quiet_NaN();
+         else if (helper::invalid_range(z, r0, r1))
+            return std::numeric_limits<T>::quiet_NaN();
+
+         const T a = scalar_t(parameters[0])();
+
+         for (std::size_t i = r0; i <= r1; ++i)
+         {
+            z[i] = (a * x[i]) + y[i];
+         }
+
+         return T(1);
+      }
+   };
+
+   template <typename T>
+   class axpbyz : public exprtk::igeneric_function<T>
+   {
+   public:
+
+      typedef typename exprtk::igeneric_function<T> igfun_t;
+      typedef typename igfun_t::parameter_list_t    parameter_list_t;
+      typedef typename igfun_t::generic_type        generic_type;
+      typedef typename generic_type::scalar_view    scalar_t;
+      typedef typename generic_type::vector_view    vector_t;
+
+      using exprtk::igeneric_function<T>::operator();
+
+      axpbyz()
+      : exprtk::igeneric_function<T>("TVTVV|TVTVVTT")
+        /*
+           z <- ax + by
+           Overloads:
+           0. TVTVV   - a, x(vector), b, y(vector), z(vector)
+           1. TVTVVTT - a, x(vector), b, y(vector), z(vector), r0, r1
+        */
+      {}
+
+      inline T operator() (const std::size_t& ps_index, parameter_list_t parameters)
+      {
+         const vector_t x(parameters[1]);
+         const vector_t y(parameters[3]);
+               vector_t z(parameters[4]);
+
+         std::size_t r0 = 0;
+         std::size_t r1 = std::min(x.size(),y.size()) - 1;
+
+         if ((1 == ps_index) && !helper::load_vector_range<T>::process(parameters, r0, r1, 4, 5, 1))
+            return std::numeric_limits<T>::quiet_NaN();
+         else if (helper::invalid_range(y, r0, r1))
+            return std::numeric_limits<T>::quiet_NaN();
+         else if (helper::invalid_range(z, r0, r1))
+            return std::numeric_limits<T>::quiet_NaN();
+
+         const T a = scalar_t(parameters[0])();
+         const T b = scalar_t(parameters[2])();
+
+         for (std::size_t i = r0; i <= r1; ++i)
+         {
+            z[i] = (a * x[i]) + (b * y[i]);
+         }
+
+         return T(1);
+      }
+   };
+
+   template <typename T>
+   class axpbz : public exprtk::igeneric_function<T>
+   {
+   public:
+
+      typedef typename exprtk::igeneric_function<T> igfun_t;
+      typedef typename igfun_t::parameter_list_t    parameter_list_t;
+      typedef typename igfun_t::generic_type        generic_type;
+      typedef typename generic_type::scalar_view    scalar_t;
+      typedef typename generic_type::vector_view    vector_t;
+
+      using exprtk::igeneric_function<T>::operator();
+
+      axpbz()
+      : exprtk::igeneric_function<T>("TVTV|TVTVTT")
+        /*
+           z <- ax + b
+           Overloads:
+           0. TVTV   - a, x(vector), b, z(vector)
+           1. TVTVTT - a, x(vector), b, z(vector), r0, r1
+        */
+      {}
+
+      inline T operator() (const std::size_t& ps_index, parameter_list_t parameters)
+      {
+         const vector_t x(parameters[1]);
+               vector_t z(parameters[3]);
+
+         std::size_t r0 = 0;
+         std::size_t r1 = x.size() - 1;
+
+         if ((1 == ps_index) && !helper::load_vector_range<T>::process(parameters, r0, r1, 4, 5, 1))
+            return std::numeric_limits<T>::quiet_NaN();
+         else if (helper::invalid_range(z, r0, r1))
+            return std::numeric_limits<T>::quiet_NaN();
+
+         const T a = scalar_t(parameters[0])();
+         const T b = scalar_t(parameters[2])();
+
+         for (std::size_t i = r0; i <= r1; ++i)
+         {
+            z[i] = (a * x[i]) + b;
+         }
+
+         return T(1);
+      }
+   };
+
+   template <typename T>
+   class dot : public exprtk::igeneric_function<T>
+   {
+   public:
+
+      typedef typename exprtk::igeneric_function<T> igfun_t;
+      typedef typename igfun_t::parameter_list_t    parameter_list_t;
+      typedef typename igfun_t::generic_type        generic_type;
+      typedef typename generic_type::scalar_view    scalar_t;
+      typedef typename generic_type::vector_view    vector_t;
+
+      using exprtk::igeneric_function<T>::operator();
+
+      dot()
+      : exprtk::igeneric_function<T>("VV|VVTT")
+        /*
+           Overloads:
+           0. VV   - x(vector), y(vector)
+           1. VVTT - x(vector), y(vector), r0, r1
+        */
+      {}
+
+      inline T operator() (const std::size_t& ps_index, parameter_list_t parameters)
+      {
+         const vector_t x(parameters[0]);
+         const vector_t y(parameters[1]);
+
+         std::size_t r0 = 0;
+         std::size_t r1 = std::min(x.size(),y.size()) - 1;
+
+         if ((1 == ps_index) && !helper::load_vector_range<T>::process(parameters, r0, r1, 2, 3, 0))
+            return std::numeric_limits<T>::quiet_NaN();
+         else if (helper::invalid_range(y, r0, r1))
+            return std::numeric_limits<T>::quiet_NaN();
+
+         T result = T(0);
+
+         for (std::size_t i = r0; i <= r1; ++i)
+         {
+            result += (x[i] * y[i]);
+         }
+
+         return result;
+      }
+   };
+
+   template <typename T>
+   class dotk : public exprtk::igeneric_function<T>
+   {
+   public:
+
+      typedef typename exprtk::igeneric_function<T> igfun_t;
+      typedef typename igfun_t::parameter_list_t    parameter_list_t;
+      typedef typename igfun_t::generic_type        generic_type;
+      typedef typename generic_type::scalar_view    scalar_t;
+      typedef typename generic_type::vector_view    vector_t;
+
+      using exprtk::igeneric_function<T>::operator();
+
+      dotk()
+      : exprtk::igeneric_function<T>("VV|VVTT")
+        /*
+           Overloads:
+           0. VV   - x(vector), y(vector)
+           1. VVTT - x(vector), y(vector), r0, r1
+        */
+      {}
+
+      inline T operator() (const std::size_t& ps_index, parameter_list_t parameters)
+      {
+         const vector_t x(parameters[0]);
+         const vector_t y(parameters[1]);
+
+         std::size_t r0 = 0;
+         std::size_t r1 = std::min(x.size(),y.size()) - 1;
+
+         if ((1 == ps_index) && !helper::load_vector_range<T>::process(parameters, r0, r1, 2, 3, 0))
+            return std::numeric_limits<T>::quiet_NaN();
+         else if (helper::invalid_range(y, r0, r1))
+            return std::numeric_limits<T>::quiet_NaN();
+
+         T result = T(0);
+         T error  = T(0);
+
+         for (std::size_t i = r0; i <= r1; ++i)
+         {
+            details::kahan_sum(result, error, (x[i] * y[i]));
+         }
+
+         return result;
+      }
+   };
+
+   template <typename T>
+   struct package
+   {
+      all_true   <T> at;
+      all_false  <T> af;
+      any_true   <T> nt;
+      any_false  <T> nf;
+      count      <T>  c;
+      copy       <T> cp;
+      rol        <T> rl;
+      ror        <T> rr;
+      shift_left <T> sl;
+      shift_right<T> sr;
+      sort       <T> st;
+      nthelement <T> ne;
+      iota       <T> ia;
+      sumk       <T> sk;
+      axpy       <T> b1_axpy;
+      axpby      <T> b1_axpby;
+      axpyz      <T> b1_axpyz;
+      axpbyz     <T> b1_axpbyz;
+      axpbz      <T> b1_axpbz;
+      dot        <T> dt;
+      dotk       <T> dtk;
+
+      bool register_package(exprtk::symbol_table<T>& symtab)
+      {
+         #define exprtk_register_function(FunctionName,FunctionType)                  \
+         if (!symtab.add_function(FunctionName,FunctionType))                         \
+         {                                                                            \
+            exprtk_debug((                                                            \
+              "exprtk::rtl::vecops::register_package - Failed to add function: %s\n", \
+              FunctionName));                                                         \
+            return false;                                                             \
+         }                                                                            \
+
+         exprtk_register_function("all_true"     ,at)
+         exprtk_register_function("all_false"    ,af)
+         exprtk_register_function("any_true"     ,nt)
+         exprtk_register_function("any_false"    ,nf)
+         exprtk_register_function("count"        , c)
+         exprtk_register_function("copy"         ,cp)
+         exprtk_register_function("rotate_left"  ,rl)
+         exprtk_register_function("rol"          ,rl)
+         exprtk_register_function("rotate_right" ,rr)
+         exprtk_register_function("ror"          ,rr)
+         exprtk_register_function("shftl"        ,sl)
+         exprtk_register_function("shftr"        ,sr)
+         exprtk_register_function("sort"         ,st)
+         exprtk_register_function("nth_element"  ,ne)
+         exprtk_register_function("iota"         ,ia)
+         exprtk_register_function("sumk"         ,sk)
+         exprtk_register_function("axpy"    ,b1_axpy)
+         exprtk_register_function("axpby"  ,b1_axpby)
+         exprtk_register_function("axpyz"  ,b1_axpyz)
+         exprtk_register_function("axpbyz",b1_axpbyz)
+         exprtk_register_function("axpbz"  ,b1_axpbz)
+         exprtk_register_function("dot"          ,dt)
+         exprtk_register_function("dotk"        ,dtk)
+         #undef exprtk_register_function
+
+         return true;
+      }
+   };
+
+   } // namespace exprtk::rtl::vecops
+   } // namespace exprtk::rtl
+}    // namespace exprtk
+#endif
+
+namespace exprtk
+{
+   namespace information
+   {
+      static const char* library = "Mathematical Expression Toolkit";
+      static const char* version = "2.7182818284590452353602874713526624977572470936999595749"
+                                   "669676277240766303535475945713821785251664274274663919320";
+      static const char* date    = "20200101";
+
+      static inline std::string data()
+      {
+         static const std::string info_str = std::string(library) +
+                                             std::string(" v") + std::string(version) +
+                                             std::string(" (") + date + std::string(")");
+         return info_str;
+      }
+
+   } // namespace information
+
+   #ifdef exprtk_debug
+   #undef exprtk_debug
+   #endif
+
+   #ifdef exprtk_error_location
+   #undef exprtk_error_location
+   #endif
+
+   #ifdef exprtk_disable_fallthrough_begin
+   #undef exprtk_disable_fallthrough_begin
+   #endif
+
+   #ifdef exprtk_disable_fallthrough_end
+   #undef exprtk_disable_fallthrough_end
+   #endif
+
+} // namespace exprtk
+
+#endif
index a71ad1c56d2b2001bf0e65cdb2e706613ba09f1a..a8047f7da7f51ad9417f7861e447e465a2a77f94 100644 (file)
@@ -779,6 +779,7 @@ void Session::start_capture(function<void (const QString)> error_handler)
                d->clear();
 
        trigger_list_.clear();
+       segment_sample_count_.clear();
 
        // Revert name back to default name (e.g. "Session 1") for real devices
        // as the (possibly saved) data is gone. File devices keep their name.
@@ -885,16 +886,17 @@ double Session::get_samplerate() const
        return samplerate;
 }
 
-uint32_t Session::get_segment_count() const
+uint32_t Session::get_highest_segment_id() const
 {
-       uint32_t value = 0;
-
-       // Find the highest number of segments
-       for (const shared_ptr<data::SignalData>& data : all_signal_data_)
-               if (data->get_segment_count() > value)
-                       value = data->get_segment_count();
+       return highest_segment_id_;
+}
 
-       return value;
+uint64_t Session::get_segment_sample_count(uint32_t segment_id) const
+{
+       if (segment_id < segment_sample_count_.size())
+               return segment_sample_count_[segment_id];
+       else
+               return 0;
 }
 
 vector<util::Timestamp> Session::get_triggers(uint32_t segment_id) const
@@ -913,6 +915,18 @@ const vector< shared_ptr<data::SignalBase> > Session::signalbases() const
        return signalbases_;
 }
 
+uint32_t Session::get_signal_count(data::SignalBase::ChannelType type) const
+{
+       return count_if(signalbases_.begin(), signalbases_.end(),
+               [&] (shared_ptr<SignalBase> sb) { return sb->type() == type; });
+}
+
+uint32_t Session::get_next_signal_index(data::SignalBase::ChannelType type)
+{
+       next_index_list_[type]++;
+       return next_index_list_[type];
+}
+
 void Session::add_generated_signal(shared_ptr<data::SignalBase> signal)
 {
        signalbases_.push_back(signal);
@@ -1297,6 +1311,7 @@ void Session::signal_new_segment()
 
        if (new_segment_id > highest_segment_id_) {
                highest_segment_id_ = new_segment_id;
+               segment_sample_count_.emplace_back(0);
                new_segment(highest_segment_id_);
        }
 }
@@ -1497,6 +1512,9 @@ void Session::feed_in_logic(shared_ptr<sigrok::Logic> logic)
 
        cur_logic_segment_->append_payload(logic);
 
+       segment_sample_count_[highest_segment_id_] =
+               max(segment_sample_count_[highest_segment_id_], cur_logic_segment_->get_sample_count());
+
        data_received();
 }
 
@@ -1563,6 +1581,9 @@ void Session::feed_in_analog(shared_ptr<sigrok::Analog> analog)
                // Append the samples in the segment
                segment->append_interleaved_samples(channel_data++, analog->num_samples(),
                        channels.size());
+
+               segment_sample_count_[highest_segment_id_] =
+                       max(segment_sample_count_[highest_segment_id_], segment->get_sample_count());
        }
 
        if (sweep_beginning) {
index 54a7444c405e1edefa4f8b410f039f9c75c61e04..91f98b581b8c0ed2a342321caf075cedff279b2d 100644 (file)
@@ -186,7 +186,8 @@ public:
 
        double get_samplerate() const;
 
-       uint32_t get_segment_count() const;
+       uint32_t get_highest_segment_id() const;
+       uint64_t get_segment_sample_count(uint32_t segment_id) const;
 
        vector<util::Timestamp> get_triggers(uint32_t segment_id) const;
 
@@ -195,6 +196,9 @@ public:
        bool has_view(shared_ptr<views::ViewBase> view);
 
        const vector< shared_ptr<data::SignalBase> > signalbases() const;
+       uint32_t get_signal_count(data::SignalBase::ChannelType type) const;
+       uint32_t get_next_signal_index(data::SignalBase::ChannelType type);
+
        void add_generated_signal(shared_ptr<data::SignalBase> signal);
        void remove_generated_signal(shared_ptr<data::SignalBase> signal);
 
@@ -286,6 +290,7 @@ private:
        vector< shared_ptr<data::SignalBase> > signalbases_;
        unordered_set< shared_ptr<data::SignalData> > all_signal_data_;
        deque<data::SignalGroup*> signal_groups_;
+       map<uint8_t, uint32_t> next_index_list_; // signal type -> index counter
 
        /// trigger_list_ contains pairs of <segment_id, timestamp> values
        vector< std::pair<uint32_t, util::Timestamp> > trigger_list_;
@@ -297,6 +302,7 @@ private:
        map< shared_ptr<sigrok::Channel>, shared_ptr<data::AnalogSegment> >
                cur_analog_segments_;
        int32_t highest_segment_id_;
+       vector<uint64_t> segment_sample_count_;
 
        std::thread sampling_thread_;
 
index 5c52ec8aaf641a6bd5d532b16613a82b136e4f22..f64b94ae4d20b4f0791689fa03cfc34544fd93d9 100644 (file)
@@ -983,22 +983,20 @@ void AnalogSignal::populate_popup_form(QWidget *parent, QFormLayout *form)
        // Add the standard options
        Signal::populate_popup_form(parent, form);
 
-       QFormLayout *const layout = new QFormLayout;
-
        // Add div-related settings
        pvdiv_sb_ = new QSpinBox(parent);
        pvdiv_sb_->setRange(0, MaximumVDivs);
        pvdiv_sb_->setValue(pos_vdivs_);
        connect(pvdiv_sb_, SIGNAL(valueChanged(int)),
                this, SLOT(on_pos_vdivs_changed(int)));
-       layout->addRow(tr("Number of pos vertical divs"), pvdiv_sb_);
+       form->addRow(tr("Number of pos vertical divs"), pvdiv_sb_);
 
        nvdiv_sb_ = new QSpinBox(parent);
        nvdiv_sb_->setRange(0, MaximumVDivs);
        nvdiv_sb_->setValue(neg_vdivs_);
        connect(nvdiv_sb_, SIGNAL(valueChanged(int)),
                this, SLOT(on_neg_vdivs_changed(int)));
-       layout->addRow(tr("Number of neg vertical divs"), nvdiv_sb_);
+       form->addRow(tr("Number of neg vertical divs"), nvdiv_sb_);
 
        div_height_sb_ = new QSpinBox(parent);
        div_height_sb_->setRange(20, 1000);
@@ -1007,7 +1005,7 @@ void AnalogSignal::populate_popup_form(QWidget *parent, QFormLayout *form)
        div_height_sb_->setValue(div_height_);
        connect(div_height_sb_, SIGNAL(valueChanged(int)),
                this, SLOT(on_div_height_changed(int)));
-       layout->addRow(tr("Div height"), div_height_sb_);
+       form->addRow(tr("Div height"), div_height_sb_);
 
        // Add the vertical resolution
        resolution_cb_ = new QComboBox(parent);
@@ -1028,7 +1026,7 @@ void AnalogSignal::populate_popup_form(QWidget *parent, QFormLayout *form)
        vdiv_layout->addWidget(resolution_cb_, 0, 0);
        vdiv_layout->addWidget(vdiv_unit, 0, 1);
 
-       layout->addRow(tr("Vertical resolution"), vdiv_layout);
+       form->addRow(tr("Vertical resolution"), vdiv_layout);
 
        // Add the autoranging checkbox
        QCheckBox* autoranging_cb = new QCheckBox();
@@ -1037,7 +1035,7 @@ void AnalogSignal::populate_popup_form(QWidget *parent, QFormLayout *form)
        connect(autoranging_cb, SIGNAL(stateChanged(int)),
                this, SLOT(on_autoranging_changed(int)));
 
-       layout->addRow(tr("Autoranging"), autoranging_cb);
+       form->addRow(tr("Autoranging"), autoranging_cb);
 
        // Add the conversion type dropdown
        conversion_cb_ = new QComboBox();
@@ -1052,7 +1050,7 @@ void AnalogSignal::populate_popup_form(QWidget *parent, QFormLayout *form)
        cur_idx = conversion_cb_->findData(QVariant(base_->get_conversion_type()));
        conversion_cb_->setCurrentIndex(cur_idx);
 
-       layout->addRow(tr("Conversion"), conversion_cb_);
+       form->addRow(tr("Conversion"), conversion_cb_);
 
        connect(conversion_cb_, SIGNAL(currentIndexChanged(int)),
                this, SLOT(on_conversion_changed(int)));
@@ -1061,7 +1059,7 @@ void AnalogSignal::populate_popup_form(QWidget *parent, QFormLayout *form)
     conv_threshold_cb_ = new QComboBox();
     conv_threshold_cb_->setEditable(true);
 
-    layout->addRow(tr("Conversion threshold(s)"), conv_threshold_cb_);
+    form->addRow(tr("Conversion threshold(s)"), conv_threshold_cb_);
 
     connect(conv_threshold_cb_, SIGNAL(currentIndexChanged(int)),
             this, SLOT(on_conv_threshold_changed(int)));
@@ -1078,15 +1076,13 @@ void AnalogSignal::populate_popup_form(QWidget *parent, QFormLayout *form)
        cur_idx = display_type_cb_->findData(QVariant(display_type_));
        display_type_cb_->setCurrentIndex(cur_idx);
 
-       layout->addRow(tr("Show traces for"), display_type_cb_);
+       form->addRow(tr("Show traces for"), display_type_cb_);
 
        connect(display_type_cb_, SIGNAL(currentIndexChanged(int)),
                this, SLOT(on_display_type_changed(int)));
 
        // Update the conversion widget contents and states
        update_conversion_widgets();
-
-       form->addRow(layout);
 }
 
 void AnalogSignal::hover_point_changed(const QPoint &hp)
diff --git a/pv/views/trace/mathsignal.cpp b/pv/views/trace/mathsignal.cpp
new file mode 100644 (file)
index 0000000..772e2d7
--- /dev/null
@@ -0,0 +1,97 @@
+/*
+ * This file is part of the PulseView project.
+ *
+ * Copyright (C) 2020 Soeren Apel <soeren@apelpie.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <extdef.h>
+
+#include <QComboBox>
+#include <QDebug>
+#include <QFormLayout>
+#include <QGridLayout>
+#include <QLineEdit>
+#include <QString>
+
+#include "mathsignal.hpp"
+
+#include "pv/data/signalbase.hpp"
+
+using pv::data::SignalBase;
+
+namespace pv {
+namespace views {
+namespace trace {
+
+#define MATHSIGNAL_INPUT_TIMEOUT (2000)
+
+MathSignal::MathSignal(
+       pv::Session &session,
+       shared_ptr<data::SignalBase> base) :
+       AnalogSignal(session, base),
+       math_signal_(dynamic_pointer_cast<pv::data::MathSignal>(base))
+{
+       delayed_expr_updater_.setSingleShot(true);
+       delayed_expr_updater_.setInterval(MATHSIGNAL_INPUT_TIMEOUT);
+       connect(&delayed_expr_updater_, &QTimer::timeout,
+               this, [this]() { math_signal_->set_expression(expression_edit_->text()); });
+}
+
+void MathSignal::populate_popup_form(QWidget *parent, QFormLayout *form)
+{
+       AnalogSignal::populate_popup_form(parent, form);
+
+       expression_edit_ = new QLineEdit();
+       expression_edit_->setText(math_signal_->get_expression());
+       connect(expression_edit_, SIGNAL(textEdited(QString)),
+               this, SLOT(on_expression_changed(QString)));
+       form->addRow(tr("Expression"), expression_edit_);
+
+       sample_count_cb_ = new QComboBox();
+       sample_count_cb_->setEditable(true);
+       sample_count_cb_->addItem(tr("same as session"));
+       sample_count_cb_->addItem(tr("100"));
+       sample_count_cb_->addItem(tr("10000"));
+       sample_count_cb_->addItem(tr("1000000"));
+       connect(sample_count_cb_, SIGNAL(editTextChanged(QString)),
+               this, SLOT(on_sample_count_changed(QString)));
+       form->addRow(tr("Number of Samples"), sample_count_cb_);
+
+       sample_rate_cb_ = new QComboBox();
+       sample_rate_cb_->setEditable(true);
+       sample_rate_cb_->addItem(tr("same as session"));
+       sample_rate_cb_->addItem(tr("100"));
+       sample_rate_cb_->addItem(tr("10000"));
+       sample_rate_cb_->addItem(tr("1000000"));
+       form->addRow(tr("Sample rate"), sample_rate_cb_);
+}
+
+void MathSignal::on_expression_changed(const QString &text)
+{
+       (void)text;
+
+       // Restart update timer
+       delayed_expr_updater_.start();
+}
+
+void MathSignal::on_sample_count_changed(const QString &text)
+{
+       (void)text;
+}
+
+} // namespace trace
+} // namespace views
+} // namespace pv
diff --git a/pv/views/trace/mathsignal.hpp b/pv/views/trace/mathsignal.hpp
new file mode 100644 (file)
index 0000000..461fd4b
--- /dev/null
@@ -0,0 +1,63 @@
+/*
+ * This file is part of the PulseView project.
+ *
+ * Copyright (C) 2020 Soeren Apel <soeren@apelpie.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef PULSEVIEW_PV_VIEWS_TRACE_MATHSIGNAL_HPP
+#define PULSEVIEW_PV_VIEWS_TRACE_MATHSIGNAL_HPP
+
+#include <QComboBox>
+#include <QString>
+#include <QTimer>
+
+#include <pv/data/mathsignal.hpp>
+#include <pv/views/trace/analogsignal.hpp>
+
+using std::shared_ptr;
+
+namespace pv {
+namespace views {
+namespace trace {
+
+class MathSignal : public AnalogSignal
+{
+       Q_OBJECT
+
+public:
+       MathSignal(pv::Session &session, shared_ptr<data::SignalBase> base);
+
+protected:
+       void populate_popup_form(QWidget *parent, QFormLayout *form);
+
+       shared_ptr<pv::data::MathSignal> math_signal_;
+
+private Q_SLOTS:
+       void on_expression_changed(const QString &text);
+       void on_sample_count_changed(const QString &text);
+
+private:
+       QLineEdit *expression_edit_;
+       QComboBox *sample_count_cb_, *sample_rate_cb_;
+       QString sample_count_text_, sample_rate_text_;
+       QTimer delayed_expr_updater_, delayed_count_updater_, delayed_rate_updater_;
+};
+
+} // namespace trace
+} // namespace views
+} // namespace pv
+
+#endif // PULSEVIEW_PV_VIEWS_TRACE_MATHSIGNAL_HPP
index 98cc0eae9d285ae46dbf739cf9575c0a20d92bf0..d1bae5e74789e05c0372fff3c055b102549bdcdc 100644 (file)
@@ -64,8 +64,8 @@ const char *const ChannelNames[] = {
 };
 
 Signal::Signal(pv::Session &session,
-       shared_ptr<data::SignalBase> channel) :
-       Trace(channel),
+       shared_ptr<data::SignalBase> signal) :
+       Trace(signal),
        session_(session),
        name_widget_(nullptr)
 {
@@ -161,10 +161,17 @@ QMenu* Signal::create_header_context_menu(QWidget *parent)
 
        menu->addSeparator();
 
-       QAction *const disable = new QAction(tr("Disable"), this);
-       disable->setShortcuts(QKeySequence::Delete);
-       connect(disable, SIGNAL(triggered()), this, SLOT(on_disable()));
-       menu->addAction(disable);
+       QString caption;
+
+       if (base_->is_generated())
+               caption = tr("Remove");
+       else
+               caption = tr("Disable");
+
+       QAction *const a = new QAction(caption, this);
+       a->setShortcuts(QKeySequence::Delete);
+       connect(a, SIGNAL(triggered()), this, SLOT(on_disable()));
+       menu->addAction(a);
 
        return menu;
 }
@@ -189,7 +196,10 @@ void Signal::on_name_changed(const QString &text)
 
 void Signal::on_disable()
 {
-       base_->set_enabled(false);
+       if (base_->is_generated())
+               session_.remove_generated_signal(base_);
+       else
+               base_->set_enabled(false);
 }
 
 void Signal::on_enabled_changed(bool enabled)
index 0674209ec06eb6a96fa1af648d97ce4f582d6b4b..ca8eea2e4a85f3820de0c6b883bed9f8e69d6812 100644 (file)
@@ -62,7 +62,7 @@ class Signal : public Trace, public ViewItemOwner
        Q_OBJECT
 
 protected:
-       Signal(pv::Session &session, shared_ptr<data::SignalBase> channel);
+       Signal(pv::Session &session, shared_ptr<data::SignalBase> signal);
 
 public:
        /**
index 6d44da2c889d8babc73cd6e2054965a1aa980a6c..ecc1aecc901a8adb9599c34e34f69ee896399727 100644 (file)
@@ -50,17 +50,17 @@ const int Trace::LabelHitPadding = 2;
 const QColor Trace::BrightGrayBGColor = QColor(0, 0, 0, 10 * 255 / 100);
 const QColor Trace::DarkGrayBGColor = QColor(0, 0, 0, 15 * 255 / 100);
 
-Trace::Trace(shared_ptr<data::SignalBase> channel) :
-       base_(channel),
+Trace::Trace(shared_ptr<data::SignalBase> signal) :
+       base_(signal),
        axis_pen_(AxisPen),
        segment_display_mode_(ShowLastSegmentOnly),  // Will be overwritten by View
        current_segment_(0),
        popup_(nullptr),
        popup_form_(nullptr)
 {
-       connect(channel.get(), SIGNAL(name_changed(const QString&)),
+       connect(signal.get(), SIGNAL(name_changed(const QString&)),
                this, SLOT(on_name_changed(const QString&)));
-       connect(channel.get(), SIGNAL(color_changed(const QColor&)),
+       connect(signal.get(), SIGNAL(color_changed(const QColor&)),
                this, SLOT(on_color_changed(const QColor&)));
 
        GlobalSettings::add_change_handler(this);
index 3ea01d464830c6b758da424931cca85f105e414f..05be7053dac7bff45888609f5e826a6744d08cf7 100644 (file)
@@ -93,7 +93,7 @@ private:
        static const QColor DarkGrayBGColor;
 
 protected:
-       Trace(shared_ptr<data::SignalBase> channel);
+       Trace(shared_ptr<data::SignalBase> signal);
        ~Trace();
 
 public:
index a1a163b05aeb649b446a2e19596602fe3b7238dc..47cb96b2da3ce6c2125a39472928e8e1a63cb1b0 100644 (file)
 
 #include <libsigrokcxx/libsigrokcxx.hpp>
 
-#include "analogsignal.hpp"
-#include "header.hpp"
-#include "logicsignal.hpp"
-#include "ruler.hpp"
-#include "signal.hpp"
-#include "tracegroup.hpp"
-#include "triggermarker.hpp"
 #include "view.hpp"
-#include "viewport.hpp"
 
+#include "pv/globalsettings.hpp"
 #include "pv/metadata_obj.hpp"
+#include "pv/session.hpp"
+#include "pv/util.hpp"
 #include "pv/data/logic.hpp"
 #include "pv/data/logicsegment.hpp"
 #include "pv/data/signalbase.hpp"
 #include "pv/devices/device.hpp"
-#include "pv/globalsettings.hpp"
-#include "pv/session.hpp"
-#include "pv/util.hpp"
+#include "pv/views/trace/mathsignal.hpp"
+#include "pv/views/trace/analogsignal.hpp"
+#include "pv/views/trace/header.hpp"
+#include "pv/views/trace/logicsignal.hpp"
+#include "pv/views/trace/ruler.hpp"
+#include "pv/views/trace/signal.hpp"
+#include "pv/views/trace/tracegroup.hpp"
+#include "pv/views/trace/triggermarker.hpp"
+#include "pv/views/trace/viewport.hpp"
 
 #ifdef ENABLE_DECODE
-#include "decodetrace.hpp"
+#include "pv/views/trace/decodetrace.hpp"
 #endif
 
 using pv::data::SignalBase;
@@ -366,7 +367,7 @@ void View::add_signalbase(const shared_ptr<data::SignalBase> signalbase)
                break;
 
        case SignalBase::MathChannel:
-               signal = shared_ptr<Signal>(new AnalogSignal(session_, signalbase));
+               signal = shared_ptr<Signal>(new MathSignal(session_, signalbase));
                break;
 
        default:
@@ -781,7 +782,7 @@ void View::set_segment_display_mode(Trace::SegmentDisplayMode mode)
        for (const shared_ptr<Signal>& signal : signals_)
                signal->set_segment_display_mode(mode);
 
-       uint32_t last_segment = session_.get_segment_count() - 1;
+       uint32_t last_segment = session_.get_highest_segment_id();
 
        switch (mode) {
        case Trace::ShowLastSegmentOnly:
index 79647a311cb352f13390322abfb018ca49bb1be5..aefe1432b14307a97a307ceb8b1975f1e7b16bc2 100644 (file)
@@ -63,6 +63,7 @@ set(pulseview_TEST_SOURCES
        ${PROJECT_SOURCE_DIR}/pv/views/trace/cursorpair.cpp
        ${PROJECT_SOURCE_DIR}/pv/views/trace/flag.cpp
        ${PROJECT_SOURCE_DIR}/pv/views/trace/header.cpp
+       ${PROJECT_SOURCE_DIR}/pv/views/trace/mathsignal.cpp
        ${PROJECT_SOURCE_DIR}/pv/views/trace/marginwidget.cpp
        ${PROJECT_SOURCE_DIR}/pv/views/trace/logicsignal.cpp
        ${PROJECT_SOURCE_DIR}/pv/views/trace/ruler.cpp
@@ -106,6 +107,7 @@ set(pulseview_TEST_SOURCES
 set(pulseview_TEST_HEADERS
        ${PROJECT_SOURCE_DIR}/pv/application.hpp
        ${PROJECT_SOURCE_DIR}/pv/devicemanager.hpp
+       ${PROJECT_SOURCE_DIR}/pv/exprtk.hpp
        ${PROJECT_SOURCE_DIR}/pv/globalsettings.hpp
        ${PROJECT_SOURCE_DIR}/pv/logging.hpp
        ${PROJECT_SOURCE_DIR}/pv/mainwindow.hpp
@@ -139,6 +141,7 @@ set(pulseview_TEST_HEADERS
        ${PROJECT_SOURCE_DIR}/pv/views/trace/flag.hpp
        ${PROJECT_SOURCE_DIR}/pv/views/trace/header.hpp
        ${PROJECT_SOURCE_DIR}/pv/views/trace/logicsignal.hpp
+       ${PROJECT_SOURCE_DIR}/pv/views/trace/mathsignal.hpp
        ${PROJECT_SOURCE_DIR}/pv/views/trace/marginwidget.hpp
        ${PROJECT_SOURCE_DIR}/pv/views/trace/ruler.hpp
        ${PROJECT_SOURCE_DIR}/pv/views/trace/signal.hpp