On Tue, 3 Jan 2012, drepper@sourceware.org wrote: > +#if __STDC__ >= 201000L It's __STDC_VERSION__ that has a new value for C11, __STDC__ remains 1. (So features.h has the correct test, but c16rtomb.c, mbrtoc16.c and uchar.h are testing the wrong macro.) -- Joseph S. Myers joseph@codesourcery.com