CHAPTER 20 ■ ENUMERATORS AND ITERATORS

The IEnumerable<T> Interface

The generic IEnumerable<T> interface is very similar to the nongeneric version, IEnumerable. The generic version derives from IEnumerable, so it must also implement the IEnumerable interface.

•Like IEnumerable, the generic version also contains a single member, a method called GetEnumerator. This version of GetEnumerator, however, returns a class object implementing the generic IEnumerator<T> interface.

•Since the class must implement two GetEnumerator methods, you should explicitly implement the nongeneric version and implement the generic version at the class level, as shown in Figure 20-7.

Figure 20-7 illustrates the implementation of the interface.

Figure 20-7. Implementing the IEnumerable<T> interface

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CHAPTER 20 ■ ENUMERATORS AND ITERATORS

The following code shows a pattern for implementing the generic interface. T is the type returned by the enumerator.

using System.Collections;

using System.Collections.Generic;

class MyGenEnumerable: IEnumerable<T>

{

}

The following code shows the use of the generic enumerable interface:

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