Make wchar_t overloads usable in module

[DanielaE]

Bring detail::find() into scope.

[DanielaE]

This might be a defect in msvc's modules implementation, but it unlocks a big chunk of my module-related compile checks.

Code like this compiles now:

import fmt;
#include <chrono>

enum class check_color {red, green, blue};
// insert appropriate formatter here

int main() {
  const auto Now = std::chrono::system_clock::now();
  auto wresult = fmt::format(L"{}", check_color::blue);
  fmt::wformat_args args = fmt::make_format_args<fmt::wformat_context>(L"hi", wresult, Now);
  wresult = fmt::vformat(L"{},{},{:%Y-%m-%d %H:%M:%S}", args);
}

Basically, I could use modularized {fmt} in production with a pre-production version of msvc 🎉

[vitaut]

For future reference could you post an error that you get without this change?

[DanielaE]

format.h(3039): error C3861: 'find': identifier not found (compiling source file check.cpp)
format.h(3845): note: see reference to function template instantiation 'void fmt::v7::detail::parse_format_string<false,wchar_t,fmt::v7::detail::format_handler<iterator,Char,fmt::v7::basic_format_context<fmt::v7::detail::buffer_appender<wchar_t>,Char>>&>(fmt::v7::basic_string_view<Char>,Handler)' being compiled
        with
        [
            Char=wchar_t,
            Handler=fmt::v7::detail::format_handler<iterator,wchar_t,fmt::v7::basic_format_context<fmt::v7::detail::buffer_appender<wchar_t>,wchar_t>> &
        ] (compiling source file check.cpp)
format.h(3890): note: see reference to function template instantiation 'void fmt::v7::detail::vformat_to<T>(fmt::v7::detail::buffer<T> &,fmt::v7::basic_string_view<wchar_t>,fmt::v7::basic_format_args<fmt::v7::basic_format_context<fmt::v7::detail::buffer_appender<T>,wchar_t>>,fmt::v7::detail::locale_ref)' being compiled
        with
        [
            T=wchar_t
        ] (compiling source file check.cpp)
check.cpp(144): note: see reference to function template instantiation 'fmt::v7::detail::buffer_appender<wchar_t> fmt::v7::format_to<wchar_t[3],int,500,wchar_t>(fmt::v7::basic_memory_buffer<wchar_t,500,std::allocator<wchar_t>> &,const S (&),int &&)' being compiled
        with
        [
            S=wchar_t [3]
        ]

[DanielaE]

This might be another defect in msvc's modules implementation. There are other problems with names not found when there are partial or total class template specifications involved. Here it's a similar situation but with function templates. May be the compiler mistakenly thinks ADL is involved even though it should be in a template specialization context resurrected from the BMI.

At least the proposed change is innocent.

[DanielaE]

This is most likely the same problem as with detail::compile_string_to_view() not being found from FMT_STRING_IMPL, i.e. the reason of the failure to compile to_wstring(T).

[vitaut]

Could you add a short comment saying that this is a workaround for an MSVC bug?

[DanielaE]

Sure.

[vitaut]

Thank you