Joel Shellman wrote:

> Sorry, the example was not intended to be directly related to the 
> subject at hand (ie. collections). It was only to reinforce the notion 
> that looking very hard at how hash code's are handled can 
> significantly affect performance in general.
>
> And yes, one solution to the issue is to create an immutable 
> collection. You might want to get fancy and make it so that immutable 
> collections can be inside mutable collections so you can represent a 
> tree (or just create specialized immutable tree data structure instead).


Sorry, typo there. immutable inside immutable of course.