C# Data Structure Like Dictionary But Without A Value

Question

Is there any data structure in C# that is like a dictionary but that only has a key and doesn\'t have a value. I basically want a list of integers that I can quickly lookup and

Answer 1

If 3.5 is not an option you could do something like Dictionary < int, int > and simply ignore the value. i've done this in 2.0 and i tend to set the value to the same as the key.