http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56086
--- Comment #1 from joseph at codesourcery dot com <joseph at codesourcery dot com> 2013-01-23 20:47:49 UTC --- Why do you think this is a bug? GCC meets the semantics of that macro (that char16_t values are UTF-16 encoded), and gnu99 mode enables u"" strings.