assertCrc(referenceCrc(bytes), bytes);
    }
  }

  private static int referenceCrc(byte[] bytes) {
    int crc = ~0;
    for (byte b : bytes) {
      crc = (crc >>> 8) ^ Crc32cHashFunction.Crc32cHasher.byteTable[(crc ^ b) & 0xFF];
    }
    return ~crc;
  }

  /**
   * Verifies that the crc of an array of byte data matches the expected value.
   *
   * @param expectedCrc the expected crc value.

     * CRC(A000A000A000...), CRC(0B000B000B...), CRC(00C000C000C...), CRC(000D000D000D...)
     * and then to XOR them together.  The strideTable enables us to hash an int followed by 12
     * zero bytes (3 ints), while the byteTable is for advancing one byte at a time.
     * This algorithm is due to the paper "Everything we know about CRC but [are] afraid to forget"
     * by Kadatch and Jenkins, 2010.
     */

    Crc32cHasher() {
      super(16);

  public void testConcatIntersectionType() {
    Iterable<A> aIterable = ImmutableList.of();
    Iterable<B> bIterable = ImmutableList.of();

    Predicate<X> xPredicate = Predicates.alwaysTrue();
    Predicate<Y> yPredicate = Predicates.alwaysTrue();

    FluentIterable<?> unused =
        FluentIterable.concat(aIterable, bIterable).filter(xPredicate).filter(yPredicate);

    /* The following fails to compile:
     *