Is it possible to refactor this extension method?

Question

I have the following extension method:

public static void ThrowIfArgumentIsNull(this T value, string argument) 
    where T : class
{
    if (value          


        

Answer 1

No, you can't do this. It would be nice, but it's not possible without some sort of AOP getting involved. I'm sure PostSharp can do a nice job, hopefully using attributes, and in Code Contracts it would just be:

Contract.Requires(qwerty != null);

Ideally I'd like a PostSharp attribute which generates the Code Contracts call - and I'll play around with that at some point - but until then, the extension method you've got is the best approach I've found...

(If I ever try the PostSharp + Code Contracts approach, I'll certainly blog about it, btw... Mono Cecil might make it reasonably easy too.)

EDIT: To expand on Laurent's answer, you could potentially have:

new { qwerty }.CheckNotNull();

And if you had lots of non-nullable parameters, you could have:

new { qwerty, uiop, asdfg }.CheckNotNull();

This would have to use reflection to work out the properties. There are ways that you could avoid doing the reflection on every access, building a delegate for each property and generally making it whizzy. I may investigate this for a blog post... but it's somewhat icky, and I prefer the idea of being able to just attribute the parameters...

EDIT: Code implemented, and blog post duly made. Ick, but fun