/in/foo.cc: In member function 'void Date::Diff(int)':
/in/foo.cc:23:52: error: no matching function for call to 'Date::isLeap(int&)'
   23 |                                 months[2]=28+isLeap(year);
      |                                              ~~~~~~^~~~~~
/in/foo.cc:27:13: note: candidate: 'int Date::isLeap()'
   27 |         int isLeap()
      |             ^~~~~~
/in/foo.cc:27:13: note:   candidate expects 0 arguments, 1 provided