https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90102
--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> --- I'm not sure if the original testcase is actually required to compile. Implementations are allowed to add additional constructors, and they could take an arbitrary type with a .clear() member. But as a QoI matter we do want the same code to compile with debug mode as for normal mode.
