blob: c1fcf49654626735f0449d8d5542d92e7e93607e (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
|
// Copyright 2014 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.
use std::cell::Cell;
#[derive(Copy)]
struct Foo {
x: isize
}
impl Clone for Foo {
fn clone(&self) -> Foo {
// Using Cell in any way should never cause clone() to be
// invoked -- after all, that would permit evil user code to
// abuse `Cell` and trigger crashes.
panic!();
}
}
pub fn main() {
let x = Cell::new(Foo { x: 22 });
let _y = x.get();
let _z = x.clone();
}
|
