Demonstration of reborrowing

reborrow.rs

fn incr_int(a: &mut u32) {
  *a += 1;
}

fn main() {
  let mut a = 42;
  let mut_ref = &mut a;
  incr_int(&mut *mut_ref);
  incr_int(&mut *mut_ref);

  println!("{}", *mut_ref);
}