rust/src/test/compile-fail/borrowck-reborrow-from-shorter-lived-andmut.rs
Niko Matsakis 419ac4a1b8 Issue #3511 - Rationalize temporary lifetimes.
Major changes:

- Define temporary scopes in a syntax-based way that basically defaults
  to the innermost statement or conditional block, except for in
  a `let` initializer, where we default to the innermost block. Rules
  are documented in the code, but not in the manual (yet).
  See new test run-pass/cleanup-value-scopes.rs for examples.
- Refactors Datum to better define cleanup roles.
- Refactor cleanup scopes to not be tied to basic blocks, permitting
  us to have a very large number of scopes (one per AST node).
- Introduce nascent documentation in trans/doc.rs covering datums and
  cleanup in a more comprehensive way.
2014-01-15 18:34:38 -05:00

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Rust

// Copyright 2012 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.
// Test that assignments to an `&mut` pointer which is found in a
// borrowed (but otherwise non-aliasable) location is illegal.
struct S<'a> {
pointer: &'a mut int
}
fn copy_borrowed_ptr<'a,'b>(p: &'a mut S<'b>) -> S<'b> {
S { pointer: &mut *p.pointer } //~ ERROR lifetime of `p` is too short to guarantee its contents can be safely reborrowed
}
fn main() {
let mut x = 1;
{
let mut y = S { pointer: &mut x };
let z = copy_borrowed_ptr(&mut y);
*y.pointer += 1;
*z.pointer += 1;
}
}