[tubs]

In my experience if you're doing perf critical stuff with string formatting you won't be using anything like fmt or printf, and for everything else the runtime difference is almost entirely unimportant.

[vitaut]

{fmt} is commonly used for performance critical code because it provides some of the fastest numeric formatting and I/O:

* https://vitaut.net/posts/2020/fast-int-to-string-revisited/ * https://github.com/fmtlib/fmt/pull/1882 * https://vitaut.net/posts/2020/optimal-file-buffer-size/

Here's just one example: https://aras-p.info/blog/2022/02/03/Speeding-up-Blender-.obj...

[tubs]

Of that blog post the float formatting is a tiny fraction (excuse the pun) of the perf win.

[vitaut]

It's just one example showing a decent win with minimal efforts. {fmt} is widely used for getting better perf in formatted code.