{"ast_node_type":"variable","tokens":[{"end":38,"kind":"keyword","start":0,"text":"let"}]}
        let mut trailing_plus = false;
    fn parse_ty_tuple_or_parens(&mut self, lo: Span, allow_plus: AllowPlus) -> PResult<'a, TyKind> {
        let (ts, trailing) = self.parse_paren_comma_seq(|p| {