Several small and specialized classes are preferred to a single bulky class that contains hundreds of member data members and member functions. More than once I’ve seen programmers extending a class with additional member functions and data members instead of using more plausible object-oriented techniques such as derivation. As a rule, a class that exceeds a 20-30 member function count is suspicious. Gigantic classes are problematic for at least three reasons: users of such classes rarely know how to use them properly; the implementation and interface of such classes tend to undergo extensive changes and bug-fixes; and they are less than ideal base classes.