https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114240
--- Comment #6 from Jonathan Wakely <redi at gcc dot gnu.org> --- Actually the standard does support Howard's intended behaviour: "If the parse fails to decode a valid date, is.setstate(ios_base::failbit) is called and tp is not modified." It says "date", not "time point" or "UTC time" or anything like that.
