Size of C++ classes

Question

Here is the code which prints size of different classes

#include 

using namespace std;

class EmptyClass
{    
};

class AbstractClass
{
  publi         


        

Answer 1

NotAbstrClass has no data members, so it too is an empty class. Since classes cannot be zero-sized, you get the same treatment as EmptyClass.

MixClass has a virtual function, and 1 non-static data member. It seems each of these (vptr and int) occupy 4 bytes on your platform, so the size is 8 bytes.