C++

 I had a question for a C++ programmer. Thought I might find one here :)


I have 2 classes that need to reference each other.

"headerA.h"
class A{
public:
   int x;
   int y;
   B *left;
   B *right;
}

"headerB.h"
class B{
public:
   int a;
   int b;
   A *parent;
   char foo();
}

Give that top is of type A, in top.left.foo() I need to modify top.right.a

Any ideas? I've tried passing a A* in the constructor for B, but the 
compiler doesn't
realize that A is a class when I try to compile, and complains about no 
type listed.

I seams to be a circular reference since A needs B and B needs A. This 
cannot be that
unusual, and has probably been solved before, I just don't know how.

Right now moy only though is to make parent a void* and the cast it to a 
A* in the
implementation of B. That removes all type checking though and I'd 
rather not abuse
void pointers like that.

    -Thomas