rust/src/test/run-pass/alt-implicit-copy-unique.rs

// 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 main() {
    let x = ~{mut a: ~10, b: ~20};
    match x {
      ~{a: ref mut a, b: ref b} => {
        assert **a == 10; *a = ~30; assert **a == 30;
      }
    }
}