C++ pointer multi-inheritance fun

Question

I\'m writing some code involving inheritance from a basic ref-counting pointer class; and some intricacies of C++ popped up. I\'ve reduced it as follows:

Suppose I h

Answer 1

• does pa point to a valid A object?
• does pb point to a valid B object?

Yes, the C* gets converted so that pa and pb point to the correct addresses.

• does pa == pb ?

No, usually not. There can't be an A object and a B object at the same address.

Furthermore, does

• pc == (C*) pa ?
• pc == (C*) pb ?

The cast converts the pointers back to the address of the C object, so both equalities are true.