Specifying fsu::Deque < T >

The traditional assumptions on previous slide, plus
Non-traditional additional requirements

• PopFront(), Front(), PopBack(), Back(), and Empty()
  all have runtime Θ(1) and runspace +Θ(1)
• PushFront(t), PushBack(t)
  have amortized runtime Θ(1) and runspace +O(size)
• Random access iterators (bracket operator, "pointer" arithmetic) are supported
• All iterator operations have runtime Θ(1) and runspace Θ(1)