val b0 = this[index].code
  val b1 = this[index + 1].code
  return (b0 shl 7) + b1
}

/**
 * An extremely generic binary search that doesn't know what data it's searching over. The caller
 * provides indexes and a comparison function, and this calls that function iteratively.
 *
 * @return the index of the match. If no match is found this is `(-1 - insertionPoint)`, where the