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// 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<int>, y: &'r Option<int>) -> &'r Option<int> {
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).get(), 3);
}
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