Implementation of the card abstraction

An implementation file contains the method bodies associated with the class member functions. The implementation file must include the interface file, which is accomplished using the include preprocessor directive. Note that the function names in the methods must specify both the class and method, but that C++ uses a double colon for this purpose, instead of the dot used by Object Pascal.

[audio] [real] Text to accompany slide22, in Chapter 3 of An Introduction to Object-Oriented Programming