Method operator -

include/hx/FieldRef.h:197–197

   bool operator !() { return ! mObject->__GetItem(mIndex)->__ToInt(); }
   int operator ~() { return ~ mObject->__GetItem(mIndex)->__ToInt(); }
   double operator -() { return - mObject->__GetItem(mIndex)->__ToDouble(); }

   inline bool operator==(const null &) const { return !mObject; }
   inline bool operator!=(const null &) const { return mObject; }