Function class_contains

std/re/src/main/matcher.rs:285–287

(items: &[ClassItem], c: char)

}

fn class_contains(items: &[ClassItem], c: char) -> bool {
    items.iter().any(|it| item_match(it, c))
}

/* Case variants to test for ignorecase class membership. */
fn fold_variants(c: char) -> [char; 2] {