| // Copyright 2015 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. |
| |
| use std::mem; |
| |
| fn leak<T>(mut b: Box<T>) -> &'static mut T { |
| // isn't this supposed to be safe? |
| let inner = &mut *b as *mut _; |
| mem::forget(b); |
| unsafe { &mut *inner } |
| } |
| |
| fn evil(mut s: &'static mut String) |
| { |
| // create alias |
| let alias: &'static mut String = s; |
| let inner: &str = &alias; |
| // free value |
| *s = String::new(); //~ ERROR cannot assign |
| let _spray = "0wned".to_owned(); |
| // ... and then use it |
| println!("{}", inner); |
| } |
| |
| fn main() { |
| evil(leak(Box::new("hello".to_owned()))); |
| } |
