Question

When defining a member function pointer that points to a function inherited privately from a base class, how would you declare it?

eg..

// class B defined here

class A; //forward dec

typedef void (B::*fnc_ptr)(); // This? or..
typedef void (A::*fnc_ptr)(); // this...?

class A: private B{
   public:
      A(): ptr(0){};
      ~A(){};

      using B::fnc;

      void setandcall(){
           ptr = &fnc;
           (*ptr)();
      }

      fnc_ptr ptr;
};

Answer 1

You have not attached the error you are getting. I think your real error might be that both

typedef (B::*fnc_ptr)(); // This? or..
typedef (A::*fnc_ptr)(); // this...?

of your choices don’t have a return type specified.

That being said both of your constructs will work. You problem is that when you invoke a non static member function you need to pass this parameter. The private inheritance only affects consumers of A not A itself.

class B
{
public:
    void fnc();

};


typedef void (B::*fnc_ptr)(); // This? or..

class A: private B{



   public:
      A(): ptr(0){};
      ~A(){};


      void setandcall(){
          ptr = &B::fnc;
          (this->*fnc)();
      }

      fnc_ptr ptr;
};