Earlier quoted context omitted.
There most certainly is getwchar() and fgetwc()/getwc() on anything that's POSIX C95, so that's more or less everything that's not a vintage antique. Reading individual UTF-8 codepoints is a trivial exercise if byte width getchar() were available, and portable C code to do so would be able to run on anything made after 1982. IIRC, they don't teach how to write portable C code in Comp Sci programs anymore and it's a s…
> There most certainly is getwchar() and fgetwc()/getwc() on anything that's POSIX C95, so that's more or less everything that's not a vintage antique. Apologies for the imprecision: by OS API, I meant syscall, at least on POSIX systems. The functions you refer to are C stdio things. Note also they implement on top of read(2) one of the two options I mentioned: "loop over getting the next N bytes and getting all comp…
> Our comments are part of a thread discussing this prompt [2] that specifically requests Rust and this snippet in response [3]. Not portable C code. You can use those C stdio functions from Rust, but you really shouldn't without a very good reason. Rust has its own IO library that is safe and well integrated with other Rust things like `#![derive(Debug)]`.
Duh. It doesn't really matter what Rust has have went it comes to enabling the use of specific edge-case performance improvements for specific purposes. Inefficient AI-generated code without a clue of other approaches doesn't move the needle. Religious purity doesn't matter, only results matter.