http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45923
--- Comment #1 from Jason Merrill <jason at gcc dot gnu.org> 2010-10-07 15:35:45 UTC --- (In reply to comment #0) > constexpr-basic.cc:20:33: error: ‘double complex::real() const’ is not a > constexpr function > > NO! Yes. It is not valid for real() to be constexpr in a non-literal class, so it is not constexpr.