Ok, I geeked out, and this is probably more information than you need. But it completely answers the question. Sorry.
Locally, I'm at this commit:
$ git show commit d6cd1e2bd19e03a81132a23b2025920577f84e37 Author: jnthn <email@example.com> Date: Sun Apr 15 16:35:03 2012 +0200
When I added FIRST/NEXT/LAST, it was idiomatic but not quite so fast. This makes it faster. Another little bit of masak++'s program.