* gordon.is.a.mo...@gmail.com:

Hello,

I have what I suppose is a simple problem, but I'm not sure the proper
way to fix it. I have two classes, one which I want to derive from
another (the first one which is derived from a third party library
class):

//MyClassA.h

#include"MyClassB.h"

class MyClassA : public LibraryClass
{

friend class TestSuite; //just for test rig

public:
MyClassA(void);
~MyClassA(void);

private:
MyClassB* myb_;
};

The trouble is, it doesn't know about MyClassB unless I add the
include directive for MyClassB in this header (I am using #pragma once
to avoid header file redefinitions, I was using include guards
before).

You can just forward-declare

class MyClassB;

before the MyClassA definition.

And I want to derive MyClassB from MyClassA because I need access to
the third party library macros:

Access to macros has nothing to do with class derivation.

Cheers, & hth.,