I don't think this is true except maybe on ancient architectures. function ptrs are usually just addresses (64 bits on most modern computers). virtual member

I don't think this is true except maybe on ancient architectures. function ptrs are usually just addresses (64 bits on most modern computers). virtual member function ptrs can have an extra bit of info to resolve the this ptr at runtime. so usually (but not always), sizeof(int ptr) == sizeof(func ptr)