src/test/run-pass/borrowed-ptr-pattern-option.rs

   1 // Copyright 2012 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11
  12 fn select<'r>(x: &'r Option<isize>, y: &'r Option<isize>) -> &'r Option<isize> {
  13     match (x, y) {
  14         (&None, &None) => x,
  15         (&Some(_), _) => x,
  16         (&None, &Some(_)) => y
  17     }
  18 }
  19
  20 pub fn main() {
  21     let x = None;
  22     let y = Some(3);
  23     assert_eq!(select(&x, &y).unwrap(), 3);
  24 }