C# 4.0 How-To

Chapter 9. Generics

IN THIS CHAPTER

• Create a Generic List

• Create a Generic Method

• Create a Generic Interface

• Create a Generic Class

• Create a Generic Delegate

• Use Multiple Generic Types

• Constrain the Generic Type

• Convert IEnumerable<Child> to IEnumerable<Parent> (Covariance)

• Convert IComparer<Parent> to IComparer<Child> (Contravariance)

• Create Tuples (Pairs and More)

Generics are a way to declare types, interfaces, delegates, and methods in a type-agnostic way. For example, IComparable<T> defines an interface that specifies a comparison between objects of type T. The T is defined by you where needed.

One of the most common ways to use generics is in collection classes. Before generics, the ArrayList was commonly used to ...