 
   final override func get() -> T?
   {
-    if closed && (tail &- head) <= 0 { return nil }
+    if closed != 0 && (tail &- head) <= 0 { return nil }
 
     dispatch_semaphore_wait(filled, DISPATCH_TIME_FOREVER)
     OSSpinLockLock(&rlock)


  final override func close()
  {
    if closed { return }

    OSSpinLockLock(&wlock)
    closed = true
    OSSpinLockUnlock(&wlock)

    dispatch_semaphore_signal(filled)
    dispatch_semaphore_signal(empty)
  }

  /**

    }
    else
    {
      assert(closed != 0, __FUNCTION__)
      OSSpinLockUnlock(&rlock)
      dispatch_semaphore_signal(filled)
      return nil
