How can I access the last object added to a HashSet?

Question

I have a HashSet that is a collection of client sockets. When a client connects, the socket is added to the HashSet. I then need to access that socket, but I don't know how to access it in the HashSet.

... 
clientSockets.Add(listenerSocket.EndAccept(async));
WaitForData(lastAddedSocket);
....

How could I determine what lastAddedSocket is?

Answer 1

There is no way to ask a HashSet "what was the last thing that was added to you?" The order is all jumbled up.

You should simply keep a separate variable called lastAddedSocket. Every time you add a socket to the HashSet, also assign it to lastAddedSocket. Then you will be able to look it up easily and in constant time.