http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50399
--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-09-15 09:21:30 UTC --- I think G++ is correct, see [basic.lookup.qual] In C++03 a nested-name-specifier can only refer to a class or namespace, in C++11 it can also refer to an enumeration.