class ArgParse {
public:
  ArgParse(const int& argc, char** &argv)
  {
    args = [x for x in argv];
    init();
  }
  bool is_filename();
  string filename();

  bool is_keys();
  vector<string> keys(); // these are ordered

  string logfile();
  vool is_logfile();
public:
  void init()
  {
    keys = [k for k in args if k is a key];
    filename = args[1];
    logfile_ = [if '--log' in args and args[(index next to --log)]]
  }

  vector<string> args;
  const string filename_;
  const string logfile_;
  const vector<string> keys_;
}

ArgParse ArgParse(argc, argv)
vector<string> keys = ArgParse.keys()