https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70495
--- Comment #6 from Jonathan Wakely <redi at gcc dot gnu.org> --- http://en.cppreference.com/w/cpp/language/implicit_cast#Integral_promotion
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70495
--- Comment #6 from Jonathan Wakely <redi at gcc dot gnu.org> --- http://en.cppreference.com/w/cpp/language/implicit_cast#Integral_promotion