C# 0 The Complete Reference

How Generic Types Are Instantiated

One question that is often raised when working with generics is whether the use of a generic 

class leads to code-bloat at runtime. The simple answer is no. The reason is that C# implements 

generics in a highly efficient manner that creates new constructed types only when they are 

needed. Here is how the process works.

When a generic class is compiled into MSIL, it retains all of its type parameters in their 

generic form. At runtime, when a specific instance of the class is required, the JIT compiler 

constructs a specific, executable code version of the class in which the type parameters are 

replaced by the type arguments. Each instance of the class that uses the same type arguments 

will use the same executable code version.

For example, given some generic class called