https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79797
--- Comment #2 from Marek Polacek <mpolacek at gcc dot gnu.org> --- Not sure about the validity but clang++ accepts the code.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79797
--- Comment #2 from Marek Polacek <mpolacek at gcc dot gnu.org> --- Not sure about the validity but clang++ accepts the code.