Ooh. Yes. There is a big performance downside.
It happens that -NSSet hash is implemented as set count. That means that if all your sets have 2 objects, say, then they all have the same hash, and the collection will perform very poorly.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.