https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65625
--- Comment #3 from Martin Liška <marxin at gcc dot gnu.org> --- g++ 4.8.3 output: /home/marxin/Programming/seastar/1.ii:3:26: error: template declaration of ‘int std::declval’ template <typename> int declval; ^ /home/marxin/Programming/seastar/1.ii:5:16: error: ‘declval’ in namespace ‘std’ does not name a type typename std::declval<int> a; ^ /home/marxin/Programming/seastar/1.ii:5:23: error: expected unqualified-id before ‘<’ token typename std::declval<int> a;