#ifndef COUNTEDH
#define COUNTEDH
#include <iostream>
#include <cassert>
using namespace std;

class counted {
	static unsigned _count;
	int i;
public:
	counted(int initial_i) {i = initial_i; ++_count;}
	counted(const counted& another) {i = another.i; ++_count;}
	~counted() {--_count;}

	friend bool equal(const counted& c1, const counted& c2) {
		assert(_count > 0);
		return c1.i == c2.i;
	}

	friend int average(const counted& c1, const counted& c2);

	static unsigned count() {return _count;}

	//Return true if any counted objects currently exist.
	static bool exist() {return _count > 0;}

	void print() const {
		assert(_count > 0);
		cout << i;
	}
};

inline int average(const counted& c1, const counted& c2) {
	assert(counted::_count > 0);
	return (c1.i + c2.i) / 2;
}
#endif