/*
   show an abstract data type
   or value based semantics
*/
#include <iostream>
using namespace std;


class arr{
public:
	int size;
	int *p;
	arr():size(3),p(new int[size]){
		cout << "in default con" << endl;
	}

	// copy constructor which does deep copy
	arr(arr& org){
		p = new int[org.size];
		for(int i=0; i<org.size; i++)
			p[i] = org.p[i];
	}
	// overload of assignment
	// if the overload is removed, code blows up
	arr& operator=(arr& rhs){
		if(&rhs != this){
			delete [] p;

			p = new int[rhs.size];
			for(int i=0; i<rhs.size; i++)
				p[i] = rhs.p[i];
		}
		return *this;
	}
	~arr(){delete [] p;}

	// a is pass by value which needs copy constructor
	friend ostream& operator<<(ostream &o, arr a);
};
ostream& operator<<(ostream &o, arr a){
	cout << " address in p " << a.p << endl;
	for(int i=0; i<3; i++)
		o << i << ": " << a.p[i] << endl;
	return o;
}

void main(){
	arr r, q;
	r.p[0] = 14;
	r.p[1] = 45;
	r.p[2] = 77;
	q.p[0] = -267;
	q.p[1] = -346;
	q.p[2] = -444;
	cout << "dump of r" << endl;
	cout << r << endl;
	cout << "dump of q" << endl;
	cout << q << endl;
	q = r;
	cout << "dump of q" << endl;
	cout << q << endl;
	q = q;
	cout << q << endl;


}