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Source Code

The MyExtensionsLibrary and MyExtensionsLibraryClient projects can be found under the

Chapter 13 subdirectory.

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Extending Interface Types via Extension Methods

At this point, you have seen how to extend classes (and, indirectly, structures that follow the same

syntax) with new functionality via extension methods. To wrap up our investigation of C# 2008

extension methods, allow me to point out that it is possible to extend an interface type with new

methods; however, the semantics of such an action are sure to be a bit different from what you

might expect.

Create a new Console Application named InterfaceExtensions and define a simple interface

type (IBasicMath) that contains a single method named Add(). Next, implement this interface on a

class type (MyCalc) in a fitting manner. For example: