C++ Design Patterns

Over the next few months we will be looking at Design Pattern examples using C++. Here is a good starting point from which the information in this post has been extracted.

Q: What is a Design Pattern?

A: Design Patterns represent solutions to problems what arise when developing software within a particular context.

Quote:

Each pattern describes a problem which occurs over and over again in our environment, and then describes the core of the solution to that problem, in such a way that you can use this solution a million times over, without ever doing it the same way twice.C. Alexander, The Timeless Way of Building, 1979

Quote:

Patterns help you learn from other's successes, instead of your own
failures.Mark Johnson (cited by Bruce Eckel)

Q: How many types of design patterns exist?

A: Basically, there are three categories:

Creational Patterns: deal with initializing and configuring classes and objects
Structural Patterns: deal with decoupling the interface and implementation of classes and objects
Behavioral Patterns: deal with dynamic interactions among societies of classes and objects

Q: What are good books about design patterns.

A: Here are some must-have books:
Design Patterns by Erich Gamma, Richard Helm, Ralph Johnson, John Vlissides (also known as Gang of Four)
Thinking in Patterns with Java, by Bruce Eckel
Thinking in Patterns with C++, by Bruce Eckel

Q: How can I quickly find information about a design pattern?

A: Here are some links on the web:

General
Design Patterns

Creational Patterns

Abstract Factory: Creates an instance of several families of classes
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Builder: Separates object construction from its representation
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Factory Method: Creates an instance of several derived classes
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Prototype: A fully initialized instance to be copied or cloned
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Singleton: A class of which only a single instance can exist
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Structural Patterns

Adapter: Match interfaces of different classes
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Bridge: Separates an object’s interface from its implementation
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Composite: A tree structure of simple and composite objects
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Decorator: Add responsibilities to objects dynamically
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Façade: A single class that represents an entire subsystem
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Flyweight: A fine-grained instance used for efficient sharing
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Proxy: An object representing another object
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Behavioral Patterns

Chain of Responsibility: A way of passing a request between a chain of objects
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Command: Encapsulate a command request as an object
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Interpreter: A way to include language elements in a program
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Iterator: Sequentially access the elements of a collection
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Mediator: Defines simplified communication between classes
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Memento: Capture and restore an object's internal state
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Observer: A way of notifying change to a number of classes
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State: Alter an object's behavior when its state changes
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Strategy: Encapsulates an algorithm inside a class
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Template Method: Defer the exact steps of an algorithm to a subclass
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Visitor: Defines a new operation to a class without change
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Source: Code Guru