#include <iostream>

using namespace std;

/*
class B {
	int *ptr;
};

class A {
	public:
		int x;
		double y;
		int *ptr;
};
*/

class A {
	std::string _s;
	A ();
  public:
	A (const std::string& s) { _s = s; }
	std::string get_s () { return _s; }
	std::string set_s (const std::string& s) { _s = s; }
};

int main () {
	A a ("0");
	A& b = a;
	b = a;

	cout << "a = " << a.get_s() << endl;
	cout << "b = " << b.get_s() << endl;

	b.set_s ("1");

	cout << "a = " << a.get_s() << endl;
	cout << "b = " << b.get_s() << endl;


/*	A a;

	a.x = 1;
	a.y = 2;
	a.ptr = &a.x;

	A b;

	b = a;

	cout << a.x << " " << b.x << endl;

	cout << a.y << " " << b.y << endl;

	cout << a.ptr << " " << b.ptr << endl;
*/


	return 0;
}