https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77858
Jonathan Wakely <redi at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |WAITING Last reconfirmed| |2016-10-05 Ever confirmed|0 |1 --- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> --- The precondition was added by https://wg21.link/lwg2459 but there is no exception thrown. As Marc says, please clarify what you are seeing and provide a testcase, as requested by https://gcc.gnu.org/bugs/