Method on_replacement_field

include/fmt/format.h:3804–3806

  }

  FMT_INLINE void on_replacement_field(int id, const Char*) {
    ctx.arg(id).visit(default_arg_formatter<Char>{ctx.out()});
  }

  auto on_format_specs(int id, const Char* begin, const Char* end)
      -> const Char* {