fn describe(tcx: TyCtxt, (_, def_id): (DefId, DefId)) -> String {
let id = tcx.hir.as_local_node_id(def_id).unwrap();
format!("computing the bounds for type parameter `{}`",
fn describe(tcx: TyCtxt, (_, def_id): (DefId, DefId)) -> String {
let id = tcx.hir.as_local_node_id(def_id).unwrap();
format!("computing the bounds for type parameter `{}`",