`NonZero<char>` in rustc-1.89

[hkBst]

I just wanted to let you know that I added support for NonZero<char> to rustc (rust-lang/rust#141001), which should hit stable in 1.89 (currently in beta I think). I want to use it to make C strings safer: rust-lang/literal-escaper#15.

I didn't know about this crate before, and I'm curious what you're using it for.

[A4-Tacks]

I simply implemented a NonZeroChar to replace assert_ne!('\0', n), and haven't considered CStr yet

[hkBst]

And why were you using assert_ne!('\0', n), if you don't mind my asking?

[A4-Tacks]

I used '\0' to represent a special case, and NonZeroChar can eliminate the need for repeated assertions

Like

let mode: NonZeroChar = self.close_for_nul()?;
self.try_group(mode)
    .or_else(|| self.close_for_disabled(mode))
    .unwrap_or_else(|| self.close(mode))