45 lines
1.0 KiB
Rust
45 lines
1.0 KiB
Rust
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// Copyright 2016 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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// Drop works for union itself.
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#![feature(untagged_unions)]
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struct S;
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union U {
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a: S
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}
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impl Drop for S {
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fn drop(&mut self) {
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unsafe { CHECK += 10; }
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}
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}
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impl Drop for U {
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fn drop(&mut self) {
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unsafe { CHECK += 1; }
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}
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}
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static mut CHECK: u8 = 0;
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fn main() {
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unsafe {
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let mut u = U { a: S };
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assert_eq!(CHECK, 0);
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u = U { a: S };
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assert_eq!(CHECK, 1); // union itself is assigned, union is dropped, field is not dropped
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u.a = S;
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assert_eq!(CHECK, 11); // union field is assigned, field is dropped
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}
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}
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