> Yes, definitely!  Though it depends a little bit how much complication
is involved.

Not that much, I think, the pure Python version being just a few lines
of code (plus a few more lines of boilerplate). But I'm not too familiar
with converting Python to C myself, so I may underestimate the
difficulties. It might get a little more complicated if you want to
minimize temporary allocations, for example.

> Now I'm just waiting for you to propose an implementation of integer
square root  :-).

Yes, there is also code for fast (O(M(n)) integer square roots in
libarith.py. This function would be much less useful overall as a
builtin, though.