checked_set (_hours, boost::lexical_cast<std::string> (h));
checked_set (_minutes, boost::lexical_cast<std::string> (m));
checked_set (_seconds, boost::lexical_cast<std::string> (s));
checked_set (_frames, boost::lexical_cast<std::string> (f));
checked_set (_hours, boost::lexical_cast<std::string> (h));
checked_set (_minutes, boost::lexical_cast<std::string> (m));
checked_set (_seconds, boost::lexical_cast<std::string> (s));
checked_set (_frames, boost::lexical_cast<std::string> (f));