// 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. fn select(x: &'r Option, y: &'r Option) -> &'r Option { match (x, y) { (&None, &None) => x, (&Some(_), _) => x, (&None, &Some(_)) => y } } pub fn main() { let x = None; let y = Some(3); fail_unless!(select(&x, &y).get() == 3); }