// Copyright 2012 The Rust Project Developers. See the COPYRIGHT // file at the top-level directory of this distribution and at // http://rust-lang.org/COPYRIGHT. // // Licensed under the Apache License, Version 2.0 or the MIT license // , at your // option. This file may not be copied, modified, or distributed // except according to those terms. #[legacy_modes]; enum ast { num(uint), add(&ast, &ast) } fn build() { let x = num(3u); let y = num(4u); let z = add(&x, &y); compute(&z); } fn compute(x: &ast) -> uint { match *x { num(x) => { x } add(x, y) => { compute(x) + compute(y) } } } fn map_nums(x: &ast, f: fn(uint) -> uint) -> &ast { match *x { num(x) => { return &num(f(x)); //~ ERROR illegal borrow } add(x, y) => { let m_x = map_nums(x, f); let m_y = map_nums(y, f); return &add(m_x, m_y); //~ ERROR illegal borrow } } } fn main() {}