Function empty_caps

std/re/src/main/matcher.rs:257–261

(ngroups: usize)

}

fn empty_caps(ngroups: usize) -> Caps {
    let mut v = Vec::with_capacity(ngroups + 1);
    for _ in 0..=ngroups { v.push(None); }
    v
}

fn is_single(node: &Node) -> bool {
    matches!(node, Node::Char(_) | Node::AnyChar | Node::Class { .. })