src/test/run-pass/borrowck-preserve-box-in-field.rs

   1 // Copyright 2012 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 // exec-env:RUST_POISON_ON_FREE=1
  12
  13 fn borrow(x: &int, f: &fn(x: &int)) {
  14     let before = *x;
  15     f(x);
  16     let after = *x;
  17     assert!(before == after);
  18 }
  19
  20 struct F { f: ~int }
  21
  22 pub fn main() {
  23     let mut x = @F {f: ~3};
  24     do borrow(x.f) |b_x| {
  25         assert!(*b_x == 3);
  26         assert!(ptr::addr_of(&(*x.f)) == ptr::addr_of(&(*b_x)));
  27         x = @F {f: ~4};
  28
  29         debug!("ptr::addr_of(*b_x) = %x", ptr::addr_of(&(*b_x)) as uint);
  30         assert!(*b_x == 3);
  31         assert!(ptr::addr_of(&(*x.f)) != ptr::addr_of(&(*b_x)));
  32     }
  33 }