<fmt/std.h> compilation failure with MinGW

[hchataing]

Foreword: I not able to reproduce the issue outside of the original context (building AOSP).

Triggered an error when compiling for windows with mingw instead of MSVC.
The code assumes that string_type returned by std::filesystem::path::native is wstring, when it is basic_string<char>.
This causes the following error (include paths redacted):

external/fmtlib/include/fmt/std.h:80:10: error: no matching constructor for initialization of 'to_utf8<wchar_t>'
  return to_utf8<wchar_t>(p.native(), to_utf8_error_policy::replace);
         ^                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
external/fmtlib/include/fmt/format.h:1424:12: note: candidate constructor not viable: no known conversion from 'const string_type' (aka 'const basic_string<char>') to 'basic_string_view<wchar_t>' for 1st argument
  explicit to_utf8(basic_string_view<WChar> s,
           ^
external/fmtlib/include/fmt/format.h:1418:66: note: candidate constructor (the implicit copy constructor) not viable: requires 1 argument, but 2 were provided
template <typename WChar, typename Buffer = memory_buffer> class to_utf8 {
                                                                 ^
external/fmtlib/include/fmt/format.h:1418:66: note: candidate constructor (the implicit move constructor) not viable: requires 1 argument, but 2 were provided
external/fmtlib/include/fmt/format.h:1423:3: note: candidate constructor not viable: requires 0 arguments, but 2 were provided
  to_utf8() {}
  ^

[vitaut]

Here's a tentative fix: 050d41e. Does it solve the problem?

[hchataing]

Thanks for the quick fix 👍
There is a different compilation issue now :

external/fmtlib/include/fmt/std.h:86:3: error: no matching function for call to 'write_escaped_string'
  write_escaped_string<wchar_t>(std::back_inserter(buf), p.native());
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
external/fmtlib/include/fmt/format.h:1963:6: note: candidate function template not viable: no known conversion from 'const string_type' (aka 'const basic_string<char>') to 'basic_string_view<wchar_t>' for 2nd argument
auto write_escaped_string(OutputIt out, basic_string_view<Char> str)
     ^
external/fmtlib/include/fmt/std.h:93:13: error: redefinition of 'write_escaped_path<char>'
inline void write_escaped_path<std::filesystem::path::value_type>(
            ^
external/fmtlib/include/fmt/std.h:83:13: note: previous definition is here
inline void write_escaped_path<char>(memory_buffer& quoted,

[vitaut]

Applied a similar fix to write_escaped_string in 4548d1e. Please let me know if it helped.

[hchataing]

That solved the compilation issue, thanks !