https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90050 --- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> --- See https://bugs.launchpad.net/ubuntu/+source/gcc-8/+bug/1824721 where I said: "for now the short answer is "C++17 support in GCC 8 is experimental, the onus is on you to link correctly"