Function __parse_on

system/lib/libcxx/src/experimental/tzdb.cpp:363–374

}

[[nodiscard]] static __tz::__on __parse_on(istream& __input) {
  if (std::isdigit(__input.peek()))
    return chrono::__parse_day(__input);

  if (std::tolower(__input.peek()) == 'l') {
    chrono::__matches(__input, "last");
    return weekday_last(chrono::__parse_weekday(__input));
  }

  return __tz::__constrained_weekday{
      chrono::__parse_weekday(__input), chrono::__parse_comparison(__input), chrono::__parse_day(__input)};
}

[[nodiscard]] static seconds __parse_duration(istream& __input) {
  seconds __result{0};