Function operator-

3party/opening_hours/opening_hours.cpp:159–165

}

HourMinutes operator-(HourMinutes const & hm)
{
  HourMinutes result;
  result.SetHours(-hm.GetHours());
  result.SetMinutes(-hm.GetMinutes());
  return result;
}

std::ostream & operator<<(std::ostream & ost, HourMinutes const & hm)
{