assign a member function to a function pointer

Question

If I have two classes like this :

class A
{
    public:
        int *(*fun)( const int &t );
        A( int *( *f )( const int &t ) ) : fun( f ) {}
};
         


        

Answer 1

Your code looks confusing and, personally, I believe that C function pointers look ugly on C++'s OO implementation. So I would advise you to use the std::function. It only has been available since C++11. If you cannot use it, try looking on Boost's Implementation.

I can give you an example of how to use the std::function:

bool MyFunction(int i)
{
    return i > 0;
}

std::function funcPointer = MyFunction;

Using this you will drastically improve your code reliability. As of your problem, specifically:

class A
{
public:
    std::function fun;
    A(std::function f) : fun(f) {}
};

class B
{
private:
    float r;
    int *f(const int &t)
    {
        return new int(int(r) + t);
    }
    A *a;
    B()
    {

        std::function tempFun = std::bind(&B::f, this, _1);
        a = new A(tempFun);
    }
};

You have to add the following namespace:

using namespace std::placeholders;