#include <iostream>
#include <exception>
#include <string>
#include <algorithm>

class copy_tracker
{
	int v;
public:
	copy_tracker()
		: v(0)
	{
		std::cout << "copy_tracker::copy_tracker()" << std::endl;
	}

	copy_tracker( const copy_tracker& c )
		: v( c.v )
	{
		std::cout << "copy_tracker::copy_tracker( copy_tracker& c )" << std::endl;
	}

	void use_object()
	{
		std::cout << v << std::endl;
	}
};

copy_tracker copy_tracker_return_by_value2()
{
	return copy_tracker();
}

copy_tracker copy_tracker_return_by_value()
{
	return copy_tracker_return_by_value2();
}

void copy_tracker_pass_by_value2(copy_tracker o)
{
	return o.use_object();
}

void copy_tracker_pass_by_value(copy_tracker o)
{
	return copy_tracker_pass_by_value2(o);
}

void test_copy_tracker()
{
	std::cout << "Return by value and assign." << std::endl;
	copy_tracker o = copy_tracker_return_by_value();
	std::cout << "Pass lvalue." << std::endl;
	copy_tracker_pass_by_value( o );
	std::cout << "Pass rvalue." << std::endl;
	const copy_tracker& o2 = copy_tracker_return_by_value();
	copy_tracker_pass_by_value2( o2 );
	std::cout << "Pass rvalue 2." << std::endl;
	copy_tracker_pass_by_value2( copy_tracker_return_by_value() );
}

int main ( void )
{try{

	test_copy_tracker();
	return 0;
}
catch ( const std::exception& e )
{
	std::cerr << std::endl
			<< "std::exception(\"" << e.what() << "\")." << std::endl;
}
catch ( ... )
{
	std::cerr  << std::endl
			<< "unknown exception." << std::endl;
}}