Follow Techotopia on Twitter

On-line Guides
All Guides
eBook Store
iOS / Android
Linux for Beginners
Office Productivity
Linux Installation
Linux Security
Linux Utilities
Linux Virtualization
Linux Kernel
System/Network Admin
Scripting Languages
Development Tools
Web Development
GUI Toolkits/Desktop
Mail Systems
Eclipse Documentation

How To Guides
General System Admin
Linux Security
Linux Filesystems
Web Servers
Graphics & Desktop
PC Hardware
Problem Solutions
Privacy Policy




Thinking in C++ Vol 2 - Practical Programming
Prev Home Next

Avoiding MI

When the question of whether to use multiple inheritance comes up, ask at least two questions:

1.      Do you need to show the public interfaces of both these classes through your new type? (See instead if one class can be contained within the other, with only some of its interface exposed in the new class.)

2.      Do you need to upcast to both of the base classes? (This also applies when you have more than two base classes.)

If you can answer no to either question, you can avoid using MI and should probably do so.

Watch for the situation where one class needs to be upcast only as a function argument. In that case, the class can be embedded and an automatic type conversion function provided in your new class to produce a reference to the embedded object. Any time you use an object of your new class as an argument to a function that expects the embedded object, the type conversion function is used.[130] However, type conversion can t be used for normal polymorphic member function selection; that requires inheritance. Preferring composition over inheritance is a good overall design guideline.

Thinking in C++ Vol 2 - Practical Programming
Prev Home Next

   Reproduced courtesy of Bruce Eckel, MindView, Inc. Design by Interspire