     // Note: We perform on UInts to get faster unsigned math (masking).
     let element = UInt(bitPattern: element)
     let capacity = UInt(bitPattern: Word.capacity)
-    return Int(bitPattern: element % capacity)
+    return Int(bitPattern: element & (capacity &- 1))
   }
 
   @inlinable

  @inlinable
  @inline(__always)
  internal static func wordCount(forCapacity capacity: Int) -> Int {
    return (capacity + Word.capacity - 1) / Word.capacity
  }

  @inlinable
  internal var capacity: Int {
    @inline(__always)
    get {
      return wordCount * Word.capacity
    }
  }


  }

  @inlinable
  internal static var shift: Int {
    @inline(__always)
    get {
      return UInt.bitWidth.trailingZeroBitCount
    }
  }

  @inlinable
  @inline(__always)
  internal func uncheckedContains(_ bit: Int) -> Bool {
    _sanityCheck(bit >= 0 && bit < UInt.bitWidth)
