rust/src/test/compile-fail/borrowck-closures-use-after-free.rs
Patrick Walton de70d76373 librustc: Remove cross-borrowing of Box<T> to &T from the language,
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]
2014-07-17 14:05:36 -07:00

33 lines
886 B
Rust

// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
// Tests that a closure which mutates a local variable
// cannot also be supplied a borrowed version of that
// variable's contents. Issue #11192.
struct Foo {
x: int
}
impl Drop for Foo {
fn drop(&mut self) {
println!("drop {}", self.x);
}
}
fn main() {
let mut ptr = box Foo { x: 0 };
let test = |foo: &Foo| {
ptr = box Foo { x: ptr.x + 1 };
};
test(&*ptr); //~ ERROR cannot borrow `*ptr`
}