/in/foo.cc: In member function 'int Date::Diff(Date&)':
/in/foo.cc:52:25: error: no matching function for call to 'Date::Pass()'
   52 |             int num=Pass();
      |                     ~~~~^~
/in/foo.cc:33:13: note: candidate: 'int Date::Pass(int, int, int)'
   33 |         int Pass(int y,int m,int d)
      |             ^~~~
/in/foo.cc:33:13: note:   candidate expects 3 arguments, 0 provided
/in/foo.cc:55:29: error: no matching function for call to 'Date::YearDay()'
   55 |             num += d.YearDay()-d.Pass();
      |                    ~~~~~~~~~^~
/in/foo.cc:48:13: note: candidate: 'int Date::YearDay(int)'
   48 |         int YearDay(int y) { return 365+isLeap(y); }
      |             ^~~~~~~
/in/foo.cc:48:13: note:   candidate expects 1 argument, 0 provided
/in/foo.cc:55:38: error: no matching function for call to 'Date::Pass()'
   55 |             num += d.YearDay()-d.Pass();
      |                                ~~~~~~^~
/in/foo.cc:33:13: note: candidate: 'int Date::Pass(int, int, int)'
   33 |         int Pass(int y,int m,int d)
      |             ^~~~
/in/foo.cc:33:13: note:   candidate expects 3 arguments, 0 provided