Robert Ramey wrote:

...

In addition to all that, from/to_chars are standard C++17, so Charconv can be used by libraries that want to support C++11 (or 14) today, but at the same time want to be able to switch to the standard functions later when increasing the minimal supported standard to C++17.

So this is an implementation in C++11 of a library which is already accepted (and presumably shipping) in C++17 ? And the only user who would use this is someone who has C++11 but can't upgrade to C++17? Doesn't seem like very many people to me.

Users... and library authors whose libraries still support C++11/14, such as Boost.JSON.

I didn't find an documentation for this.

The work-in-progress documentation is here: https://develop.charconv.cpp.al/