how about log10?

[p-avital]

Leaving this issue here to remind myself to add log10 to the digit counting techniques on your benches. Will probably do it this week. This technique should be near constant time, but I have doubts on how well it will actually perform since I guess others would have used it.

Leaving a comment on YouTube comment on Alexandrescu's Fastware detailing it :)

[p-avital]

Ended up running it in Rust because it was faster to rewrite it than to figure out how to compile and use yours.

I kinda expected it : ceil.log10 version is slower (on the plus side, it is constant time) than all others.