18.23.txt

Exercise 18.23: Using the hierarchy in exercise 18.22 along with class D
defined below, and assuming each class defines a default constructor, which, if
any, of the following conversions are not permitted?

	class D : public X, public C { ... };
	D *pd = new D;
	(a) X *px = pd;
	(b) A *pa = pd;
	(c) B *pb = pd;
	(d) C *pc = pd;

By Faisal Saadatmand

(a) Allowed: derived-to-base conversion; D is derived from X
(b) Allowed: derived-to-base conversion; D is derived from C, which is derived
	from B, which is derived from A.
(b) Allowed: derived-to-base conversion; D is derived from C, which is derived
	from B.
(c) Allowed: derived-to-base conversion; D is derived from C