http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52521
--- Comment #9 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-03-16 20:50:14 UTC --- What in the release notes should be updated? The standard says that for 180_degrees the compiler should try to call operator "" _degrees (180ULL) (if operator "" _degrees (unsigned long long) exists), or operator "" _degrees ("180") (if operator "" _degrees (const char *) exists), or operator "" _degrees <'1', '8', '0'> () (if literal operator template exists). So your testcase is invalid.