[laserbeam]

> I am actually kind of surprised the author spent so much time figuring it out.

I wouldn't be. People learn different programming techniques at different times. I'd actually assume quite a lot of programmers don't know what a bump allocator is and eventually run into one in the wild. Kudos for the author for successfully debugging and discovering that.

> One would guess the point of this would be to destroy the entire allocator on every iteration

Not necessarily every iteration, but yes, these allocators are meant to be reset to 0 at a known time, when it's safe to do so.