Oh hey, C++17 is official

or rather it was official a month or so ago. -std=c++17 works in gcc 7 and clang 5

but tbh this is the only improvement I've been able to do that I couldn't do under -std=c++1z: https://sdfn-01.ninjawedding.org/media/7Eydcaqklh_EfoU9OVc