class B;
class classA{
public:
  classA(classB* bB):B(bB){;}
  operator int(void){return FB->value;}
private:
  classB* B;
};
class classB{
friend classA;

public:
  classA* A;
  classB():value(0),
       A(this)// <<==---- warning C4355
    {;} 

private:
  int value;
};

main()
{
  classB B;

  int value = B.A;
}