[Bug c++/52094] ICE on definition of nested class in wrong namespace scope with wrong nested-name-qualifier

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52094

--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> 2012-02-02 
10:25:54 UTC ---
If the nested class is declared in an enclosing namespace scope (as required)
but still with the nested-name-qualifier of the derived type, G++ accepts it:

namespace N { struct A { struct Inner; }; }
namespace NN { struct AA : N::A {}; }
struct NN::AA::Inner {}; 

Clang++ and Comeau both reject this.