Life is just like a main routine in C/C++.
As soon as we were born, the prototype was defined in a header file.
To live is to write the function.
But sometimes we have to invoke a subroutine, in the worst case, we run into a dead loop.
Now I want to break the loop. however it may return NULL.
Thus, it's real time to say goodbye to the subroutine.
Girl, goodbye to you.