http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48399
--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-04-01 11:14:21 UTC --- other compilers such as clang and EDG reject your example too, so firefox already can't be compiled with those compilers, the example relies on a bug in previous GCC releases which was never portable and has been fixed
