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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// ignore-tidy-linelength
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#![feature(untagged_unions)]
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#[derive(Clone, Copy)]
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struct S {
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a: u8,
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b: u16,
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}
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union U {
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s: S,
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c: u32,
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}
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impl Clone for U {
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fn clone(&self) -> Self { *self }
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}
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impl Copy for U {}
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fn main() {
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unsafe {
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{
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let mut u = U { s: S { a: 0, b: 1 } };
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let ra = &mut u.s.a;
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let b = u.s.b; // OK
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}
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{
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let mut u = U { s: S { a: 0, b: 1 } };
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let ra = &mut u.s.a;
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let b = u.c; //~ ERROR cannot use `u.c` because it was mutably borrowed
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}
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}
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}
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