Design for collections upgrades

[Rémi Forax]

  Le 10/03/2011 11:46, "Zdeněk Troníček" a écrit :
> To me it seems logical that filter() returns the same collection as was
> the original collection. For Set you do not have any other choice either:
>
> set.filter(predicate)
>
> cannot switch from HashSet to TreeSet or back.
>
> Z.

How do you implement that ?

R.