class Base
{
  public:
    virtual int function(void) = 0;
};

class NotBase
{  
  public:
    NotBase(int foo) : data(foo) { }
    ~NotBase() {}

    int data;
  
    virtual int function (void) { return data; }
};

int size1 = sizeof(Base);
int size2 = sizeof(NotBase);

static NotBase nb(1234);