https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88395
--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to Emmanuel Le Trong from comment #0) > Both trunk and 8.2.1 segfault on this valid snippet And 7.4.1 too. The flag -std=c++2a isn't relevant, only -fconcepts is needed.