# Re: apparently only with extension methods nil != System::Object

**URL:** <https://www.ruby-forum.com/t/re-apparently-only-with-extension-methods-nil-system-object/166974>\
**Category:** IronRuby\
**Created:** [May 1, 2009, 4:25pm UTC](https://www.ruby-forum.com/t/re-apparently-only-with-extension-methods-nil-system-object/166974 "2009-05-01T16:25:08Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![barby](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/c57346/32.png) [@barby](https://www.ruby-forum.com/u/barby)\
**Post date:** [May 1, 2009, 4:25pm UTC](https://www.ruby-forum.com/t/re-apparently-only-with-extension-methods-nil-system-object/166974/1 "2009-05-01T16:25:08Z")

</div>

I’ve done some more investigation and it appears that it has to do with  
Extension methods.

public static bool IsNull(this object value)  
{  
return value == null;  
}

and

public static bool IsNull2(object value)  
{  
return value == null;  
}

> > > System::Web::Mvc::IronRuby::Extensions::ObjectExtensions.is\_null nil  
> > > :0: can’t convert NilClass into Object (TypeError)

> > > System::Web::Mvc::IronRuby::Extensions::ObjectExtensions.is\_null2 nil  
> > > =\> true

I’ve commented the issue on codeplex but couldn’t change the title of  
the  
bug.

* * *

Author of IronRuby in Action ([http://manning.com/carrero](http://manning.com/carrero))

Andy Warhol  
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- “I am a deeply superficial person.”