Robin Moussu a2baabbf71 Fix variant test for libstdc++ version 9 (#1515)
By using non-trivially copyable types, we force libstdc++-9's variant to
properly enter the valueless-by-exception state for our stringification
test.

Related to #1511
2019-01-26 18:32:17 +01:00
..
2018-07-02 17:32:47 +02:00