{"ast_node_type":"variable","tokens":[{"end":73,"kind":"keyword","start":0,"text":"let"}]}
            let def = if let hir::ExprKind::Path(ref qpath) = expr.kind {
        ) -> Option<(Ty<'tcx>, Ty<'tcx>)> {
                cx.qpath_res(qpath, expr.hir_id)