http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52521
--- Comment #8 from Andy Webber <andy at aligature dot com> 2012-03-16 20:06:52 UTC --- Ah, that fixes it. It could be good to update the release notes to match. Thanks to Ed Smith-Rowland, G++ now implements C++11 user-defined literals. // Not actually a good approximation. :) constexpr long double operator"" _degrees (long double d) { return d * 0.0175; } long double pi = 180_degrees; long double pi = 180.0_degrees;