{"ast_node_type":"variable","tokens":[{"end":94,"kind":"keyword","start":0,"text":"let"}]}
                let () = entry.or_insert_with(|| ty::BoundVariableKind::Const).expect_const();
                let var = ty::BoundVar::from_usize(index);
                ty::Const::new_bound(self.tcx, ty::INNERMOST, BoundConst { var })