Calling ODE solver (odeint) within c++ class

Question

I need to solve ODE equations set with odeint library. "main.cpp" file is only to call calculation (it will be extended later, here simple version to keep code clean)

main.cpp

#include "calc.h"

int main()
{
    calc c;
    c.startC();
    return 0;
}

Here is the calc header, starC(); is set public. calc.h

#ifndef MAIN_H
#define MAIN_H

#include <iostream>
#include <boost/numeric/odeint.hpp>
#include <math.h>

using namespace std;
using namespace boost::numeric::odeint;

typedef std::vector< double > vector_type;

class calc
{
public:
    int main();
    void startC();
private:
    void solveODE(const vector_type &y , vector_type &ODE , const double t );
    void printR();

};

#endif // MAIN_H

Here is the main calculation part. Also here the error occurs: calc.cpp

include <iostream>

#include <boost/numeric/odeint.hpp>
#include <math.h>

#include "calc.h"

using namespace std;
using namespace boost::numeric::odeint;

const double g = 0.15;


void calc::solveO( const vector_type &y , vector_type &ODE , const double t )
{
    dy[0] =  y[1];
    dy[1] = -y[0] - g*y[1];
}

void calc::printR(const vector_type &y, const double t)
{
    cout << t << endl;
    cout << y[0] << endl;
}

void calc::startC()
{
    const double dt = 0.1;
    typedef runge_kutta_dopri5<vector_type> stepper_type;
    vector_type y(2);
    //Initial conditins
    y[0]=   1.0;
    y[1]=   0.0;


    //Initializing of ODE solver
    integrate_const(make_dense_output<stepper_type>( 1E-12, 1E-6 ), 
                    this->*solveO, y, 0.0, 1.0, dt , printResults); //ERROR HERE
}

int calc::main()
{
    return 0;
}

This operation ends with error on the level of "Initializing of ODE solver" with:

'((calc*)this)->calc::solveO' cannot be used as a member pointer,
since it is of type '<unresolved overloaded function type>'

What's wrong with this call:

this->*solveO

And what's the correct way to call solveO inside "integrate_const"?

Edit: Thanks to the help of @tobi303 and @rbelli it now works. Here I post sum-up, TL:DR explanation:

The easiest solution is to make solveO and printR free function and call:

integrate_const(make_dense_output<stepper_type>( 1E-12, 1E-6 ), solveO, y, 0.0, 1.0, dt , printR);

Answer 1

If integrate_const takes a function pointer you cannot pass a member function pointer. Member function pointers are different from function pointers, because they implicitly need this as argument.

As you dont use any members of the class inside solveO you can simply make it a free function:

void solveO( const vector_type &y , vector_type &ODE , const double t )
{
    dy[0] =  y[1];
    dy[1] = -y[0] - g*y[1];
}