https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89118
--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> ---
The classic "C" locale does not use UTF-8, so the codecvt<wchar_t, char,
mbstate_t> facet doesn't perform conversions to UTF-8.
If I use:
std::locale::global(std::locale("C.UTF-8"));
then the results are correct. I think that's the correct behaviour.
