static L<Int> wrapIntArrayAsList(int[] l) {
  ret new RandomAccessAbstractList<Int>() {
    public int size() { ret l.length; }
    public Int get(int i) { ret l[i]; }
    public Int set(int i, Int val) {
      Int a = l[i];
      l[i] = val;
      ret a;
    }
  };
}