Question

I have got four classes A, B, C and D.

• Class A has a member b of class
  B.
• Class B has a member c of class C.

A has a member D* dpointer;

This hierarchy has to be preserved (in fact this is a GUI with app, window, panel as A, B and C).

Now B and C must use a method from *dpointer.

Is there something more elegant than giving dpointer as a member of B and C ? Is it bad ?

Answer 1

In this situation you should probably pass a reference to B and C instead of a pointer. As @Billy ONeil says in his answer, you should use a shared_ptr or a scoped_ptr if possible and appropriate (cannot judge without knowing more about D and dpointer) in A.
Passing a reference to B and C has the advantage of making clear that these two merely use
the D-object, but do not control it’s lifecycle, and that an instance of D is required to use these classes (with a pointer NULL would be an option). If B and C only call const methods on D, you can even pass a const reference.