https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67991
--- Comment #7 from Jacob McIntosh <nacitar at ubercpp dot com> --- Per a thread on the isocpp group(linked in the OP), N4268's wording was incorporated shortly before C++14's ratification, so it's unclear to me why this is a C++1z feature and not a C++14 feature.
