| // 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 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| |
| fn select<'r>(x: &'r Option<isize>, y: &'r Option<isize>) -> &'r Option<isize> { |
| match (x, y) { |
| (&None, &None) => x, |
| (&Some(_), _) => x, |
| (&None, &Some(_)) => y |
| } |
| } |
| |
| pub fn main() { |
| let x = None; |
| let y = Some(3); |
| assert_eq!(select(&x, &y).unwrap(), 3); |
| } |
