[dllthomas]

Hm, glib answers aside, you're right. I think the real point is that counting writes makes no sense because it is both not the most expensive and not the most frequent operation involved. Really, the whole thing comes from looking at lists wrong. Find-and-delete is not O(1), and converting half of an O(n) operation to O(1) doesn't actually make an asymptotic difference. If you are genuinely just performing inserts and removals of known elements things will look different.