http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60271
--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> --- Even if max_element() isn't made constexpr, we can make __max_element constexpr (once the FE supports it) and use it directly in max. It's certainly solvable, I just wanted to create this PR so we don't forget about it.