/in/foo.cc: In constructor 'Time::Time()':
/in/foo.cc:8:23: warning: converting to non-pointer type 'int' from NULL [-Wconversion-null]
    8 |         Time() : hour(NULL), min(NULL), second(NULL){}
      |                       ^~~~
/in/foo.cc:8:34: warning: converting to non-pointer type 'int' from NULL [-Wconversion-null]
    8 |         Time() : hour(NULL), min(NULL), second(NULL){}
      |                                  ^~~~
/in/foo.cc:8:48: warning: converting to non-pointer type 'int' from NULL [-Wconversion-null]
    8 |         Time() : hour(NULL), min(NULL), second(NULL){}
      |                                                ^~~~