A use for multiple inheritance?

Question

Can anyone think of any situation to use multiple inheritance? Every case I can think of can be solved by the method operator

AnotherClass() { return this-&         


        

Answer 1

Most people use multiple-inheritance in the context of applying multiple interfaces to a class. This is the approach Java and C#, among others, enforce.

C++ allows you to apply multiple base classes fairly freely, in an is-a relationship between types. So, you can treat a derived object like any of its base classes.

Another use, as LeopardSkinPillBoxHat points out, is in mix-ins. An excellent example of this is the Loki library, from Andrei Alexandrescu's book Modern C++ Design. He uses what he terms policy classes that specify the behavior or the requirements of a given class through inheritance.

Yet another use is one that simplifies a modular approach that allows API-independence through the use of sister-class delegation in the oft-dreaded diamond hierarchy.

The uses for MI are many. The potential for abuse is even greater.