Due to the nature of our client base, we still target .NET 2.0 at work. The side-effect being, of course, the inability to use the latest and greatest and sexiest of what C# has to offer these days.

I was setting out to write some static helper methods this morning, and on a lark decided to Google for extension method support. Sometimes the compiler is nice enough to take 3.0 features (such as the var keyword) and translate them into code that’s palatable for .NET 2.0.

Truly, ask and ye shall receive! Success! While in newer versions of the framework, you’d import System.Core.dll to add extension support, all that’s really needed is the definition of the ExtensionAttribute class. This can be added anywhere in your code that targets .NET 2.0:

namespace System.Runtime.CompilerServices
{
    public sealed class ExtensionAttribute : Attribute { }
}

Extensions work like a charm after that.