Question

I feel that using GetEnumerator() and casting IEnumerator.Current is expensive. Any better suggestions?

I’m open to using a different data structure if it offers similiar capabilities with better performance.

After thought:
Would a generic stack be a better idea so that the cast isn’t necessary?

Answer 1

Have you done any benchmarks, or are they just gut feelings?

If you think that the majority of the processing time is spent looping through stacks you should benchmark it and make sure that that is the case. If it is, you have a few options.

1. Redesign the code so that the looping isn’t necessary
2. Find a faster looping construct. (I would recommend generics even though it wouldn’t matter that much. Again, do benchmarks).

EDIT:

Examples of looping that might not be necessary are when you try to do lookups in a list or match two lists or similar. If the looping takes a long time, see if it make sense to put the lists into binary trees or hash maps. There could be an initial cost of creating them, but if the code is redesigned you might get that back by having O(1) lookups later on.