Although unique_ptrs cannot be copied, in § 12.1.5 (p. 471) we wrote a clone function that...

Although unique_ptrs cannot be copied, in § 12.1.5 (p. 471) we wrote a clone function that returned a unique_ptr by value. Explain why that function is legal and how it works.

§ 12.1.5 (p. 471)

Exercise 12.16

Compilers don’t always give easy-to-understand error messages if we attempt to copy or assign a unique_ptr. Write a program that contains these errors to see how your compiler diagnoses them.

Exercise 12.17

Which of the following unique_ptr declarations are illegal or likely to result in subsequent program error? Explain what the problem is with each one.

int ix = 1024, *pi = &ix, *pi2 = new int(2048);typedef unique_ptr IntP;

(a) IntP p0(ix);

(b) IntP pl(pi);

(c) IntP p2(pi2);

(d) IntP p3(&ix);

(e) IntP p4(new int(2048));

(f) IntP p5(p2.get());