needless_character_iteration false positive

[aDotInTheVoid]

This transformation isn't correct:

fn main() {
    let s = "Beyoncé";
    // EVERY character isn't ascii
    dbg!(s.chars().all(|c| !char::is_ascii(&c)));
    // ANY character isn't ascii
    dbg!(!s.is_ascii());
}

[src/main.rs:3:5] s.chars().all(|c| !char::is_ascii(&c)) = false
[src/main.rs:4:5] !s.is_ascii() = true

Originally posted by @aDotInTheVoid in #12815 (comment)

CC @GuillaumeGomez

[GuillaumeGomez]

Thanks! Gonna send a fix in the next days.

[aDotInTheVoid]

@rustbot modify labels: I-false-positive C-bug