mozilla/rust — pull request #6003 by thestinger (2013-04-22 17:08:10+00:00)
Title: cell: public field is unsafe

use core::cell;

fn main() {
let x = cell::Cell(Some(~"foo"));
let y = x.value.get_ref().get_ref();
do x.with_mut_ref |z| { *z = None; }
println(*y) // boom!
}