[dllthomas]

> (I'd cache that mask with the array to reduce runtime calculations)

So, store size-1 instead of size, and add one when asked for the size? I can see that, though I'm not confident it's worth the conceptual overhead.

If you mean storing it in addition to the size, I think that's a bad trade - cache is far more precious than many decrements.

Of course, if the size is fixed at compile time, the mask will probably be stored baked into the instructions (andl <const>, ...).