{"ast_node_type":"other","tokens":[{"end":86,"kind":"keyword","start":0,"text":"///"}]}
    /// For each arm of the input, whether that arm is useful after the arms above it.
pub struct UsefulnessReport<'p, Cx: PatCx> {
    pub arm_usefulness: Vec<(MatchArm<'p, Cx>, Usefulness<'p, Cx>)>,