d6bd8d8491
This change has two consequences: 1. It makes `Arc<T>` and `Rc<T>` covariant in `T`. 2. It causes the compiler to reject code that was unsound with respect to dropck. See compile-fail/issue-29106.rs for an example of code that no longer compiles. Because of this, this is a [breaking-change]. Fixes #29037. Fixes #29106.
35 lines
916 B
Rust
35 lines
916 B
Rust
// Copyright 2015 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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use std::rc::Rc;
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use std::sync::Arc;
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struct Foo<'a>(&'a String);
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impl<'a> Drop for Foo<'a> {
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fn drop(&mut self) {
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println!("{:?}", self.0);
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}
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}
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fn main() {
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{
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let (y, x);
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x = "alive".to_string();
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y = Arc::new(Foo(&x)); //~ ERROR `x` does not live long enough
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}
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{
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let (y, x);
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x = "alive".to_string();
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y = Rc::new(Foo(&x)); //~ ERROR `x` does not live long enough
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}
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}
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