http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53333
--- Comment #5 from Marc Glisse <glisse at gcc dot gnu.org> 2012-05-12 21:57:05 UTC --- (In reply to comment #4) > For other features of C++11 don't need -pedantic-errors to emit an error. [...] > It doesn't seem consistent. > What is the criteria? Allowing {} is a rather isolated extension that doesn't interfere much with anything. Rvalue reference is perhaps the worst example you could pick as it changes the behavior all over the place and can easily break code. I don't know if there are official criteria, the choices may be questionable, but I don't see that it matters that much...