assertEquals("[]", new AtomicDoubleArray(0).toString());
    assertEquals("[]", new AtomicDoubleArray(new double[0]).toString());
  }

  /** compareAndSet treats +0.0 and -0.0 as distinct values */
  public void testDistinctZeros() {
    AtomicDoubleArray aa = new AtomicDoubleArray(SIZE);
    for (int i : new int[] {0, SIZE - 1}) {
      assertFalse(aa.compareAndSet(i, -0.0, 7.0));
      assertFalse(aa.weakCompareAndSet(i, -0.0, 7.0));