C++ Passing pointer to non-static member function

Question

Hi everyone :) I have a problem with function pointers
My \'callback\' function arguments are:
1) a function like this: int(*fx)(int,int)
2) an int variable: int a<

Answer 1

I would do it with std functors, here is a simple example based off of your code:

#include 
#include 
using namespace std;

class A{
private:
    int x;
public:
    A(int elem){
        x = elem;
    }

    static int add(int a, int b){
        return a + b;
    }

    int sub(int a, int b) const{
        return x - (a + b);
    }
};

void callback( std::function fx, A obj, int a, int b)
{
    cout << "Value of the callback: " << fx( obj, a, b) << endl;
}

int main()
{
A obj(5);


    std::function Aprinter= &A::sub;

    callback(Aprinter,obj,1,2);
}