Function invoke_parse

include/fmt/base.h:1667–1674

Suppress an ld warning on macOS (#3769).

template <typename T, typename Char>
FMT_VISIBILITY("hidden")  // Suppress an ld warning on macOS (#3769).
FMT_CONSTEXPR auto invoke_parse(parse_context<Char>& ctx) -> const Char* {
  using mapped_type = remove_cvref_t<mapped_t<T, Char>>;
  constexpr bool formattable =
      std::is_constructible<formatter<mapped_type, Char>>::value;
  if (!formattable) return ctx.begin();  // Error is reported in the value ctor.
  using formatted_type = conditional_t<formattable, mapped_type, int>;
  return formatter<formatted_type, Char>().parse(ctx);
}

template <typename... T> struct arg_pack {};