https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102592
--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jonathan Wakely <r...@gcc.gnu.org>: https://gcc.gnu.org/g:b83b810ac440f72e7551b6496539e60ac30c0d8a commit r12-4381-gb83b810ac440f72e7551b6496539e60ac30c0d8a Author: Jonathan Wakely <jwak...@redhat.com> Date: Wed Oct 13 17:19:57 2021 +0100 libstdc++: Refactor filesystem::path encoding conversions Adjust the __detail::__effective_range overloads so they always return a string or string view using std::char_traits, because we don't care about the traits of an incoming string. Use std::contiguous_iterator in the __effective_range(const Source&) overload, to allow returning a basic_string_view in more cases. For the non-contiguous casecl in both __effective_range and __string_from_range, return a std::string instead of std::u8string when the value type of the range is char8_t. These changes avoid unnecessary basic_string temporaries. Also simplify __string_from_range(Iter, Iter) to not need std::__to_address for the contiguous case. Combine the _S_convert(string_type) and _S_convert(const T&) overloads into a single _S_convert(T) function which also avoids the dangling view problem of PR 102592 (should that recur somehow). libstdc++-v3/ChangeLog: * include/bits/fs_path.h (__detail::__is_contiguous): New variable template to identify contiguous iterators. (__detail::__unified_char8_t): New alias template to decide when to treat char8_t as char without encoding conversion. (__detail::__effective_range(const basic_string<C,T>&)): Use std::char_traits<C> for returned string view. (__detail::__effective_range(const basic_string_view<C,T>&)): Likewise. (__detail::__effective_range(const Source&)): Use __is_contiguous to detect mode cases of contiguous iterators. Use __unified_char8_t to return a std::string instead of std::u8string.
