28 lines
924 B
Rust
28 lines
924 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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// exec-env:RUST_POISON_ON_FREE=1
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pub fn main() {
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let x: @mut @Option<~int> = @mut @None;
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match x {
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@@Some(ref y) => {
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// here, the refcount of `*x` is bumped so
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// `y` remains valid even if `*x` is modified.
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*x = @None;
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}
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@@None => {
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// here, no bump of the ref count of `*x` is needed, but in
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// fact a bump occurs anyway because of how pattern marching
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// works.
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}
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}
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}
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