// dfs.mro.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"

#include <iostream>

using namespace std;

struct A { 
	int data;
	A () { cout << "A() construct " << endl; } ;
	A (int init) : data(init) { cout << "A() construct with custom data " << init << endl; };
};

struct B : virtual public A { 
	int a;

	B () : A(10) { cout << "B() construct " << endl; } ;
};

struct C : virtual  public A { 
	int a;

	C () : A(20) { cout << "C() construct " << endl; } ;
};

struct D :  virtual public B, public C {
	
	// NOTE ! 
	// D gets two different 'a' variable instances 
	// since it inherits two classess with a variable
	//
	// but only a single data instance 
	// since it inherits only one clas with data instance

	D  () : A(40) { cout << "D() construct " << endl; } ;
};


int main() {
	D* t1 = new D;

	// data is a single variable among all classes

	cout << "t1->B::data is " << t1->B::data << endl ;
	cout << "t2->C::data is " << t1->C::data << endl;
	cout << "t3->data is " << t1->data << endl;

	// virtual class inheritance brings a 4 bytes overhead

	cout << "size of A " << sizeof (A) << endl;
	cout << "size of B " << sizeof (B) << endl;
	cout << "size of C " << sizeof (C) << endl;
	cout << "size of D " << sizeof (D) << endl;

	return 0;
}