{"ast_node_type":"function","tokens":[{"end":80,"kind":"keyword","start":0,"text":"fn"}]}
    fn parse_expr_borrow(&mut self, lo: Span) -> PResult<'a, (Span, ExprKind)> {
    /// Parse `& mut? <expr>` or `& raw [ const | mut ] <expr>`.
        self.expect_and()?;