struct S {
  v: i32
}

fn main()
{
  let cell = std::cell::RefCell::new(S{v:666});
  let r1;
  let r2;
  {
    let mut r3   = cell.borrow_mut();

    println!("{}", r3.v);
    r3.v = 0;
    println!("{}", r3.v)
  }
  r1   = cell.borrow();
  r2   = cell.borrow();

  println!("{} {}", r1.v, r2.v)
}