http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50454
--- Comment #6 from Paolo Carlini <paolo.carlini at oracle dot com> 2011-09-19 23:56:22 UTC --- Created attachment 25321 --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=25321 patchlet Constructively, this is something which should lead to unsigned __int128 treated exactly like plain __int128 (note: not fully tested) On x86_64 -m32, where __int128 isn't available we reject with 'template argument 1 is invalid', we don't reach grokdeclarator at all.