g++: 'protected' member function cannot be declared friend

[Matt Austern]

On Jan 31, 2005, at 1:05 PM, Fariborz Jahanian wrote:

>
> g++ issues a diagnostic on this test case.
> Section 11.4 does not address this issue, but I think that this is a 
> g++ bug. The
> fact that a member function itself is 'protected' should not prevent 
> it from accessing members of other
> classes where it is declared as 'friend'.
>
>
> % cat protected.C
> class FOO {
> protected:
>         void Push();
> };
>
> class S {
>         friend void FOO::Push();
> };

The problem is the other way around.  FOO::Push() is allowed to access 
private members of classes that declare it to be a friend, but nobody 
said that class S was allowed to access FOO's private or protected 
members.  This code is illegal.

			--Matt