Yeah..Good point, @jackhftang. A discrete log formula might yield a slightly
faster `[]`. This relates to my `# User growth policy for below?` comment and
the way I let people "guess" an initial `cap`. I have seen people target as low
as 1.10x exponential growth and as high as 4x.. a big range. Might all still be
do-able with Nim's compile-time superpowers & your way, though. Another wrinkle
is "under-populated hunks" which my search approach can support, whereas the
log assumes things are densely populated, but that may not be important. I
mostly was advocating for a `seq[ptr UncheckedArray[T]]` aka `[i][j]` idea just
one-more indirection over the linked list idea - 2 vs. "many" (if still
logarithmic). { & I did say `deques` were different. :-) } Cheers!
