Extending primitive types

Question

Is it possible to extend primitive types such as System.String and System.Int32 (IE: integer) in .Net 4 and if so how?

To be more specific, I am aware of the concept of partial classes but this doesnt seem to be the answer. Also I find that System.String is not inheritable and Int32 is a structure.

Lastly I am interested in knowing both a VB.Net and C# answer to the above question.

Thanks all..

Answer 1

You cannot extend them directly - the String class is sealed, for example, and as you noted value type wrappers (such as Int32) are normally structs.

You can write extension methods (C#, VB.NET) to them, that's what they are there for.

Another option, is to write a wrapper around these, exposing all of their properties and adding more functionality.

Answer 2

Just as additional info (Oded is right already on the other stuff):

There are no "primitive types" in .Net. Only classes and value types (called structures in C#) (and all are decendents of object).

However you cannot inherit from value types (like int, byte, ...) and you cannot inherit from sealed classes (like string).