75 lines
1.7 KiB
Rust
75 lines
1.7 KiB
Rust
// Copyright 2014 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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use std::rc::Rc;
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use std::cell::Cell;
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struct Field {
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number: usize,
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state: Rc<Cell<usize>>
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}
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impl Field {
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fn new(number: usize, state: Rc<Cell<usize>>) -> Field {
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Field {
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number: number,
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state: state
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}
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}
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}
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impl Drop for Field {
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fn drop(&mut self) {
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println!("Dropping field {}", self.number);
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assert_eq!(self.state.get(), self.number);
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self.state.set(self.state.get()+1);
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}
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}
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struct NoDropImpl {
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_one: Field,
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_two: Field,
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_three: Field
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}
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struct HasDropImpl {
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_one: Field,
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_two: Field,
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_three: Field
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}
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impl Drop for HasDropImpl {
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fn drop(&mut self) {
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println!("HasDropImpl.drop()");
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assert_eq!(self._one.state.get(), 0);
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self._one.state.set(1);
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}
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}
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pub fn main() {
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let state = Rc::new(Cell::new(1));
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let noImpl = NoDropImpl {
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_one: Field::new(1, state.clone()),
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_two: Field::new(2, state.clone()),
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_three: Field::new(3, state.clone())
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};
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drop(noImpl);
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assert_eq!(state.get(), 4);
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state.set(0);
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let hasImpl = HasDropImpl {
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_one: Field::new(1, state.clone()),
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_two: Field::new(2, state.clone()),
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_three: Field::new(3, state.clone())
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};
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drop(hasImpl);
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assert_eq!(state.get(), 4);
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}
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