55 lines
1.3 KiB
Rust
55 lines
1.3 KiB
Rust
// 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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// Check that drop elaboration clears the "master" discriminant
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// drop flag even if it protects no fields.
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struct Good(usize);
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impl Drop for Good {
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#[inline(never)]
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fn drop(&mut self) {
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println!("dropping Good({})", self.0);
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}
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}
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struct Void;
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impl Drop for Void {
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#[inline(never)]
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fn drop(&mut self) {
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panic!("Suddenly, a Void appears.");
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}
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}
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enum E {
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Never(Void),
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Fine(Good)
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}
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fn main() {
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let mut go = true;
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loop {
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let next;
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match go {
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true => next = E::Fine(Good(123)),
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false => return,
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}
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match next {
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E::Never(_) => return,
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E::Fine(_good) => go = false,
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}
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// `next` is dropped and StorageDead'd here. We must reset the
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// discriminant's drop flag to avoid random variants being
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// dropped.
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}
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}
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