std::unordered_map<std::string, void*> callbackReg;

class A
{
public:
    void foo(int a)
    {
        //impl
    }
    void foo(int a, int b)
    {
        //impl
    }
    void foo(int a, double d)
    {
        //impl
    }

};


template<class Instance , typename Function>
void register_func(Instance& obj, Function func)
{
    /* have to store function name as the key and
     - pointer to raw member function pointer as the value,
     - in callbackReg Map */
    // ---> Point B
}

int main(int argc, const char * argv[])
{
    A a;
    register_evt(a, &A::foo); //---> point A
    system("Pause");
}