http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45942
Michiel <MichieldeB at aim dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|RESOLVED |UNCONFIRMED Resolution|INVALID | --- Comment #4 from Michiel <MichieldeB at aim dot com> 2010-10-08 14:58:42 UTC --- (In reply to comment #2) > This variation uses B1 for your first attempt and B2 for your second attempt. > > template <class T, int C> class A; > > template <class T, int C, A<T,C> &a> class B1; > > template <class T, int C, A<T,C> &a> class B2; > > template <class T, int C> class A > { > template <A &a> friend class B1; > > template <A &a> friend class B2<T,C,a>; > }; > > // instantiation > template class A<char,128>; > > > This code is not valid, G++ is correct to reject it. Please explain why the code is invalid, and do not click "Resolved invalid" until ClassB is a friend of ClassA.