Navigating C++ and Object-Oriented Design

4.11. Data Member Objects

Object-oriented programming and design promote class reuse. This concept is central to the idea of “layering” software; that is, defining new classes in terms of existing classes that already work. One method of code reuse is containment, where the data members of one class are objects of a different class.

Containment offers several advantages to class designers.

• Containment hides the implementation details of data member objects. Changes to the inside view of a data member object will not affect the implementation or interface of the class that contains it.

• The compiler creates and deletes data member objects automatically, calling constructors and destructors as needed (the containing class may need to supply constructor ...