[Bug c++/29615] New: Class can't be friends of itself?

["danny dot boelens at artwork-systems dot com" <gcc-bugzilla at gcc dot gnu dot org>]

The following simple C++ file:

<test.cpp>
class A
{
  friend class A;
};

int main() { return 0; }
</test.cpp>

results in the following error when I try to compile it with g++:

$ ~/gcc-build-4.2-20061007/gcc/g++ -o test test.cpp
test.cpp:3: error: class 'A' is implicitly friends with itself

I was using a snapshot (GCC 4.2 2006/10/07), but I got the same behaviour with
several 4.1.x and 4.0.x builds on both Linux and Windows 2000 (Cygwin).

I agree that it's pointless to make a class a friend of itself (which is why I
used severity 'minor'), but I haven't found anything in my C++ spec (ISO/IEC
14882) that say it is not allowed. Please point my to the relevant section in
case I missed anything.

By the way: all other compilers I've tried accept this file without a problem.
These include Visual Studio .NET 2003, CodeWarrior 8.3, CodeWarrior 9.6 and the
online test drive for Comeau. Comeau does exactly what I'd expect:

Your Comeau C/C++ test results are as follows: 

Comeau C/C++ 4.3.8 (Aug 19 2006 13:36:48) for  ONLINE_EVALUATION_Alpha1
Copyright 1988-2006 Comeau Computing.  All rights reserved.
MODE:strict errors C++

"ComeauTest.c", line 3: warning: pointless friend declaration
       friend class A;
       ^

Not a big issue, but I thought it might be a good idea to log this anyway,
since a search didn't result in relevant hits :-)


-- 
           Summary: Class can't be friends of itself?
           Product: gcc
           Version: 4.2.0
            Status: UNCONFIRMED
          Severity: minor
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: danny dot boelens at artwork-systems dot com
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29615