https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115218
--- Comment #5 from Patrick Palka <ppalka at gcc dot gnu.org> --- Ah right, the constraint is implicitly there since the variant data member doesn't have an NSDMI. I was thinking of the case where we're default initializing via an NSDMI and so we need to explicitly the defaulted default ctor appropriately, e.g. for https://eel.is/c++draft/range.owning.view.
