Yes, I was trying to avoid the link overhead, though.

If you need to be able to insert values into your Collection,
how are you going to enforce your constraints in an enhanced ArrayList
implementation? I would think your implementation would incur
unreasonable overhead on insertion unless you use a HashSet?

I don't understand that comment in the context of requiring enforced
uniqueness. A collection with enforced uniqueness must do a search by
value for every insert operation, to find out if there is already an
equal item. If you don't have structure such as a tree or a hash map,
that search becomes extremely expensive.

If you can ensure uniqueness, then any List is fine.

Patricia

Hmm, Do you need to get the index? Or do you want to go through all of
them in order?
If you only want to get them in order, then using LinkedHashSet and
iteration is the way to go.
If you REALLY need no duplicates, AND really need to get by index, you
could do it this way:
Set<T> set;
List<T> list;
...
if (set.add(obj)) {
   list.add(obj)
};

Or, if you build the set once, then use a LinkedHashSet, and then call
toArray(), or new ArrayList(set))

Hope these suggestions help.
- Daniel