https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67491 Bug 67491 depends on bug 88075, which changed state.
Bug 88075 Summary: [feature-request] allow "concept" instead of "concept bool" with -fconcepts https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88075 What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Resolution|--- |FIXED
