Find And Remove Items From Collection

Question

What is the best way to remove a set from a collection, but still keep the items that were removed in a separate collection?

I have written an extension method that

Answer 1

Depending upon the size of your collection, you might want to implement it as a HashSet rather than a List. In sufficiently large collections (how large is "sufficient" has been somewhat dependent on what is in the collection, in my experience), HashSets can be much, much faster at finding items within themselves than Lists.