rust/src/test/compile-fail/borrowck-mut-borrow-of-mut-base-ptr.rs

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// Copyright 2013 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 attempt to mutably borrow `&mut` pointer while pointee is
// borrowed yields an error.
//
// Example from src/middle/borrowck/doc.rs
fn foo<'a>(mut t0: &'a mut int,
mut t1: &'a mut int) {
let p: &int = &*t0; // Freezes `*t0`
let mut t2 = &mut t0; //~ ERROR cannot borrow `t0`
**t2 += 1; // Mutates `*t0`
}
fn bar<'a>(mut t0: &'a mut int,
mut t1: &'a mut int) {
let p: &mut int = &mut *t0; // Claims `*t0`
let mut t2 = &mut t0; //~ ERROR cannot borrow `t0`
**t2 += 1; // Mutates `*t0` but not through `*p`
}
fn main() {
}