https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103295
--- Comment #11 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to Jonathan Wakely from comment #7) > It just doesn't allow assignment through the pointer. I think that's correct according to [class.union.general] p6: "When the left operand of an assignment operator involves a member access expression ([expr.ref]) that nominates a union member, it may begin the lifetime of that union member, as described below." `_M_local_buf[0] = 0;` is OK, but `auto p = _M_local_buf; p[0] = 0;` is not.
