Have you ever encountered the issue where you had a sequence of things, you needed the elements only once and must know what elements are duplicates? And how often they occure?
Take a look as NSCountedSet
! For example when combining multiple collections (Set
s), you can determine which elements are contained multiple times. That technique can be used to calculate the intersection of collections in a straight foreward way 🙃
Apples documentation can be found here.