[Bug libstdc++/95048] [9/10/11 Regression] wstring-constructor of std::filesystem::path throws for non-ASCII characters

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95048

--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Using std::codecvt_utf8<wchar_t> fixes it:

--- a/libstdc++-v3/include/bits/fs_path.h
+++ b/libstdc++-v3/include/bits/fs_path.h
@@ -836,8 +836,7 @@ namespace __detail
              }
          }
 #else // ! windows
-       struct _UCvt : std::codecvt<_CharT, char, std::mbstate_t>
-       { } __cvt;
+       struct _UCvt : std::codecvt_utf8<_CharT> { } __cvt;
        std::string __str;
        if (__str_codecvt_out_all(__f, __l, __str, __cvt))
          return __str;