Very nice! I do wonder if it would be useful to be able to skip even more smaller segments, maybe a ctor argument for the minimum segment size. Or maybe some housekeeping functions to collapse the smallest segments into one.

Mostly the thing that feels strange is when using say, n > 10 segments, then the smallest segment will be less than a thousandth of the largest, and iterating over the first half will access n-1 or n-2 segments, worse cache behaviour, while iterating over the second half will access 1 or two segments.

Seems like, in most cases, you would want to be able to collapse those earlier segments together.

If you do that, you lose those stable pointers.