de70d76373
except where trait objects are involved. Part of issue #15349, though I'm leaving it open for trait objects. Cross borrowing for trait objects remains because it is needed until we have DST. This will break code like: fn foo(x: &int) { ... } let a = box 3i; foo(a); Change this code to: fn foo(x: &int) { ... } let a = box 3i; foo(&*a); [breaking-change]
40 lines
1.2 KiB
Rust
40 lines
1.2 KiB
Rust
// Copyright 2012-2014 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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#![feature(managed_boxes)]
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use std::gc::GC;
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fn borrow(x: &int, f: |x: &int|) {
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let before = *x;
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f(x);
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let after = *x;
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assert_eq!(before, after);
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}
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struct F { f: Box<int> }
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pub fn main() {
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let mut x = box box(GC) F{f: box 3};
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borrow(&*x.f, |b_x| {
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//~^ ERROR cannot borrow `x` as mutable because `*x.f` is also borrowed as immutable
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assert_eq!(*b_x, 3);
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assert_eq!(&(*x.f) as *const int, &(*b_x) as *const int);
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//~^ NOTE borrow occurs due to use of `x` in closure
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*x = box(GC) F{f: box 4};
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println!("&*b_x = {:p}", &(*b_x));
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assert_eq!(*b_x, 3);
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assert!(&(*x.f) as *const int != &(*b_x) as *const int);
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})
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}
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