http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59873
--- Comment #8 from Wesley J. Landaker <wjl at icecavern dot net> --- Just as an additional point, L'\u0000' also yields a wchar_t with the value of 1. (If that is an illegal construct, it is not warned about when using -Wall -Wextra -Werror).