https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80144
--- Comment #2 from W E Brown <webrown.cpp at gmail dot com> --- > Confirmed, although I'm not sure which of those 2 options is correct... Per N4687, [temp.concept]/4: A concept shall not have associated constraints (17.4.2). Since Second's declaration does specify Never as an associated constraint, Second's declaration appears to be in error. Any such declarations ought likely be diagnosed accordingly.
