>> I'd like to have #asOrderedCollection, #asSortedCollection and
>> #asCharacterSet returning the receiver if it's already the instance of the
>> named class. It's not backwards compatibility what stops me to add these
>> methods, but the fact that adding these would result in silent errors in
>> code which relies on the copy creation.
>>
>
> The difference with backward compatibility must be too subtle for me
> to understand :)
>
> Nicolas

Same here :)

Stef