https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67491 Bug 67491 depends on bug 69096, which changed state.
Bug 69096 Summary: [concepts] return type deduction before checking constraint satisfaction https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69096 What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Resolution|--- |DUPLICATE