typeid for polymorphic types

Question

I expected this code to print \'Same 1\' and \'Same2\', but it prints only \'Same1\':

#include 
#include 
using name         


        

Answer 1

Pointers aren't polymorphic types. They don't have virtual members. In fact, they have no members whatsoever. They also cannot derive from other types, nor be used as base classes. Hence, the static and dynamic type of a T* is always T*.

In your "Same2" line, you're comparing the typeid of a pointer, not the pointed-to object. The compiler therefore only looks at the static types C* and D*. They're obviously not the same, and must have distinct type_info objects.