/in/foo.cc: In member function 'bool Date::runnian(int)':
/in/foo.cc:18:25: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
         if (y2 % 4 == 0 && y2 % 100 != 0 || y2 % 400 == 0)
             ~~~~~~~~~~~~^~~~~~~~~~~~~~~~
/in/foo.cc: In member function 'int Date::monthday(int, int)':
/in/foo.cc:36:5: warning: control reaches end of non-void function [-Wreturn-type]
     }
     ^