https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68608
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> --- (In reply to Jonathan Wakely from comment #1) > Still ICEs on current trunk with -std=c++17 -fconcepts, and also with > -std=c++2a after modernising the code: I can't get this to crash with r12-2133. But the funny thing is clang crashes with a similar issue as what GCC had: <source>:6:7: error: definition with same mangled name '_ZN1AIiE1fEv' as another definition int f() requires (!C<T>) { return 2; } ^ <source>:5:7: note: previous definition is here int f() requires C<T> { return 1; } ^