https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82745
--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> --- Please read my answer again: (In reply to Jonathan Wakely from comment #5) > This is the same issue as PR 58876, namely that the problem happens inside a > system header, so the diagnostics are suppressed by default. It has nothing > to do with perfect forwarding or std::forward. -Wsystem-headers is needed to get the warnings when the conversion happens in code inside a system-header (which is the case for lots of standard library templates). See also PR 80472
