Question

In C++, I have a class A which is friend with a class B.

I looks like inherited classes of B are not friend of class A.

I this a limitation of C++ or my mistake ?

Here is an example. When compiling, I get an error on line ‘return new Memento’:

Memento::Memento : impossible to access private member declared in Memento.

class Originator;  class Memento {   friend class Originator;    Memento() {};    int m_Data;  public:   ~Memento() {}; };  class Originator { public:   virtual Memento* createMemento() = 0; };  class FooOriginator : public Originator { public:   Memento* createMemento()   {     return new Memento; // Impossible to access private member of Memento   } };  void main() {   FooOriginator MyOriginator;   MyOriginator.createMemento();  } 

I could of course add FooOriginator as friend of Memento, but then, this means I would have to add all Originator-inherited classes as friend of Memento, which is something I’d like to avoid.

Any idea ?

Answer 1

See: Friend scope in C++
Voted exact duplicate.

I looks like inherited classes of B are not friend of class A. 

Correct

I this a limitation of C++ or my mistake ? 

It is the way C++ works. I don’t see it as a limitation.