muparsertest.cpp

#include <muParser.h>
#include <iostream>
#include <functional>
#include <boost/bind.hpp>

struct MyClass {
    double m_arbitrary_value;
    MyClass(int arbitrary_value) : m_arbitrary_value(arbitrary_value) {}
    double make_a_value(double a,  double b) {return m_arbitrary_value*a+b;}
};

double wrapper(double a, double b, MyClass* p) {
    return p->make_a_value(a, b);
}

int main(const int argc, const char** argv) {
    // 1. just call the function
    //    this works fine
    MyClass instance(5);
    std::cout << wrapper(3, 2, &instance) << std::endl;
    
    // 2. bind the function and call the resulting functor
    //    this works fine
    std::cout << boost::bind(&wrapper, _1, _2, &instance)(3, 2) << std::endl;
    
    // 3. pass the function to Parser::DefineFun
    //    this fails
    mu::Parser p;
    p.DefineFun("f", boost::bind(&wrapper, _1, _2, &instance));
    p.SetExpr("f(3, 2)");
    std::cout << p.Eval() << std::endl;

    return 0;
}