[ahh]

I'm rather proud of Abseil's implementation: https://github.com/abseil/abseil-cpp/blob/887d0eee6bab358472...

As I recall another colleague wrote the original version (I do not remember who.) I bitbashed and optimized it, and added the comments, mainly because I wanted to make sure I understood the reasons it was right.

[banachtarski]

It's uncanny but I literally looked at this an hour ago (prior to seeing this posting on HN).

Thanks for the comments/annotation!