https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80841
--- Comment #3 from Daniel Krügler <daniel.kruegler at googlemail dot com> --- (In reply to Jason Bell from comment #2) > Thanks that's a good reduced example. I've changed it slightly so it works > with constexpr input. But that is just adding additional complexity: The constexpr declaration is unnecessary when you provide an argument of reference type to a non-type template of reference type.
