44 lines
1014 B
Rust
44 lines
1014 B
Rust
// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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#![feature(unsafe_destructor)]
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use std::cell::Cell;
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#[deriving(Show)]
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struct r<'a> {
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i: &'a Cell<int>,
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}
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#[unsafe_destructor]
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impl<'a> Drop for r<'a> {
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fn drop(&mut self) {
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self.i.set(self.i.get() + 1);
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}
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}
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fn r(i: &Cell<int>) -> r {
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r {
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i: i
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}
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}
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pub fn main() {
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let i = &Cell::new(0i);
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// Even though these look like copies, they are guaranteed not to be
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{
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let a = r(i);
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let b = (a, 10i);
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let (c, _d) = b;
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println!("{}", c);
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}
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assert_eq!(i.get(), 1);
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}
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