How does the C++ compiler know which implementation of a virtual function to call?

Question

Here is an example of polymorphism from http://www.cplusplus.com/doc/tutorial/polymorphism.html (edited for readability):

// abstract base class
#include <         


        

Answer 1

To answer the second part of your question: that address probably won't have a v-table in the right place, and madness will ensue. Also, it's undefined according to the standard.