File: borrowck-loan-of-static-data-issue-27616.rs

package info (click to toggle)
rustc 1.85.0%2Bdfsg3-1
  • links: PTS, VCS
  • area: main
  • in suites: experimental, sid, trixie
  • size: 893,396 kB
  • sloc: xml: 158,127; python: 35,830; javascript: 19,497; cpp: 19,002; sh: 17,245; ansic: 13,127; asm: 4,376; makefile: 1,051; perl: 29; lisp: 29; ruby: 19; sql: 11
file content (24 lines) | stat: -rw-r--r-- 533 bytes parent folder | download | duplicates (17)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
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())));
}