definition Observer() definition getFilter() definition onNewMessage(const string &,const string &,const int &,const MessageImportance &,const time_t &) declaration setFilter(MessageImportance) definition ~Observer() definition Observer CerrLogObserver true true inheritance FileObserver true true inheritance LoggingService true false pass by reference pass by reference pass by reference pass by reference StreamLogObserver true true inheritance string true false pass by reference pass by reference time_t true false pass by reference