#include <iostream>

using namespace std;

class A {
public:
	A(int aa) : a(aa) { cout << "A constr: " << a << " -- " << this << endl; }
	~A() { cout << "A destr: " << a << " -- " << this << endl; }
	int val() const { return a; }
private:
	int a;
};

const A &makeA1() {
	A a(1);
	return a;
}

const A &makeA2() {
	return A(2);
}

A &makeA3() {
	A a(3);
	return a;
}

/*
A &makeA4() {
	return A(4);
}
*/

A &&makeA5() {
	return A(5);
}

A makeA6() {
	return A(6);
}

void useA(const A &a) {
	cout << "using A = " << a.val() << endl;
}

class B {
public:
	B(int bb) : a(bb) { cout << "B constr: " << bb << " -- " << this << endl; }
	~B() { cout << "B destr: " << a.val() << " -- " << this << endl; }
	const A &getA() const { return a; }
	A getA2() const { return a; }
private:
	A a;
};

B makeB() {
	B ret(10);
	return ret;
}

class C : public A {
public:
	C(int bb) : A(bb) { cout << "C constr: " << bb << " -- " << this << endl; }
	~C() { cout << "C destr: " << A::val() << " -- " << this << endl; }
};

C makeC() {
	C ret(100);
	return ret;
}

// inspired by GotW #88 by Herb Sutter -- google it

int main(int argc, char **argv) {
	cout << "l1" << endl;
	useA(makeA1());
	useA(makeA2());
	useA(makeA3());
	//useA(makeA4());
	useA(makeA5());
	useA(makeA6());
	cout << "------" << endl;

	useA(makeB().getA());
	useA(makeB().getA2());
	cout << "------" << endl;

	const A &a1 = makeA6();
	cout << "line 1" << endl;
	useA(a1);
	cout << "line 2" << endl;

// the following code (note the lacking "const") does not compile:
/*
	cout << "-----" << endl;
	A &a2 = makeA6();
	cout << "line 3" << endl;
	useA(a2);
	cout << "line 4" << endl;
*/

	cout << "-----" << endl;
	const A &a3 = makeC();
	cout << "line 5" << endl;
	useA(a3);
	cout << "line 6" << endl;
}