https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67491 Bug 67491 depends on bug 78173, which changed state.
Bug 78173 Summary: Hard error subtracting pointers to incomplete type in SFINAE context https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78173 What |Removed |Added ---------------------------------------------------------------------------- Status|ASSIGNED |RESOLVED Resolution|--- |FIXED
