[kadoban]

You've answered your own question implicitly. The address of the starting and ending element can change. You just define yourself where in the backing array the start/end are, and let them wrap around (use modular arithmetic for the indexes).

[panda88888]

Thanks! DEQ implementation with circular buffer. :)

Edit: should have thought of that. Brain fart—-long day at work.

[kadoban]

Exactly! I really like this stuff, little clever ways to skip effort. Data structures and algos don't get enough love :)