type class versin of http://spray.io/blog/2012-12-13-the-magnet-pattern/

magnet type class

  sealed trait CompletionMagnet[T] {
    type Result
    def complete(v: T): Result
  }
  
  implicit def statudObjectHasACompletionMagnet[T : Marshaller](tupl: (StatusCode, T)) = new CompletionMagnet[(StatusCode, T)]{
    override type Result = Unit
    override def complete(v: (StatusCode, T)) = ???
  }
  implicit def httpResponseFutureHasACompletionMagnet(future: Future[HttpResponse]) = new CompletionMagnet[Future[HttpResponse]]{
    override type Result = Int
    override def complete(v: Future[HttpResponse]): Int = ???
  }
  implicit def statusCodeFutureHasACompletionMagnet(future: Future[StatusCode]) = new CompletionMagnet[Future[HttpResponse]]{
    override type Result = Int
    override def complete(v: Future[StatusCode]) = ???
  }
  
  def complete[X](v : X)(implicit magnet: CompletionMagnet[X]): magnet.Result = magnet.complete(v)