     This is not a constant, strictly speaking. Probably close enough, though.
   */
 
-  private static var offset: CFTimeInterval = { CFAbsoluteTimeGetCurrent() - CACurrentMediaTime() }()
+  private static var offset: NSTimeInterval = { CFAbsoluteTimeGetCurrent() - CACurrentMediaTime() }()
 
   /**
     scale: how to scale from the mach timebase to nanoseconds. See Technical Q&A QA1398

    ns = Int64(nanoseconds)
  }

  init(seconds: CFTimeInterval)
  {
    ns = Int64(seconds*1e9)
  }


/**
  Timing-related utility based on mach_absolute_time().
  It seems correct on Mac OS X. It might not be on iOS.
*/

public struct Time: CustomStringConvertible
