recursive friend classes

Question

Is there any way around this:

class B;

class C { 
 public:
  C() { }
 private:
  int i;
  friend B::B();
};

class B { 
 public:
  B() { }
 private:
  int i         


        

Answer 1

I realize that this is a really silly idea, but couldn't you—theoretically—accomplish this through inheritance, by making the parent class' constructors friends? The code compiles, at least, questionable though it may be.

class A {
 public:
  A() { }
 private:
  int i;
};

class D {
 public:
  D() { }
 private:
  int i;
};

class B : public A {
 public:
  B() { }
 private:
  friend D::D();
};

class C : public D {
 public:
  C() { }
 private:
  friend A::A();
};