Is it legal to declare a friendship with a forward declared class?

Question

I have successfully constructed something similar to the following code in visual studio 2008:

class OpDevconfigSession;
class DevconfigSession
{
... 
private
   friend class OpDevconfigSession;
};

Again, this works quite well with visual studio. However, if I try to compile the code under g++ version 4.3.2, I get an error message such as:

error: friend declaration does not name a class or function

I know that standards conformance is not Microsoft's forte so I am wondering if the code that I have written breaks with the standard in some way that I do not yet understand. Does anyone have any thoughts?

Thanks

Answer 1

The following work for me in g++ ver 4.4.1.

class OpDevconfigSession;
class DevconfigSession
{
  private:
   friend class OpDevconfigSession;
};

I can't see why this might be illegal.