Function parse

external/fmt/include/fmt/std.h:283–285

                                   is_formattable<T, Char>::value) &&
                                  is_formattable<E, Char>::value>> {
  FMT_CONSTEXPR auto parse(parse_context<Char>& ctx) -> const Char* {
    return ctx.begin();
  }

  template <typename FormatContext>
  auto format(const std::expected<T, E>& value, FormatContext& ctx) const