C++: A Dialog Programming with the C++ Standard Library

The Manager/Worker Idiom Again

Why do I say “the interface” rather than “the interfaces”? Because we're going to implement these classes to give the appearance of a single type of object that can change its behavior; in other words, we're going to use the manager/worker idiom again to implement another type of polymorphic object. This will enable us to write a main program that allows access to an object of any of these types in a uniform manner. Of course, the implementation of the member functions will be somewhat different in each class, to take account of the peculiarities of that class, but the structure of the program will be essentially the same for any number of types once we've made provisions to handle more than one. For this reason, ...