Size of class with virtual function

Question

I was revising the C++ concepts, but I am stuck with a very simple code

#include 
using namespace std;

class foo {
public:
    //int i;
    void         


        

Answer 1

You're working on a platform where pointers are aligned to 8 bytes. Since the virtual table pointer is typically the first thing in the layout of an object, it too must be aligned to 8 bytes. So padding 4 bytes are inserted after the int member, that's why you get a size of 16 (8 bytes for the vf table pointer, 4 for the int and 4 padding bytes).