Deque Iterator Implementation Plan

• Public Interface
• Random Access Iterator
• Protected Data
• Pointer to a specific Deque<T> object
  (the deque into which the iterator points)
• A deque index value
  (the actual element to which the iterator points)
• Safe v. Fast iterators
• Vector::Iterator: fast, essentially a pointer
• Deque::Iterator: safe, accesses elements through Deque interface
• Discussion of "const iterator" type