Various funstions are included for debugging the cdeque class.
All assign methods (including operator=) invalidate all iterators.
If capacity exceeded invalidates all iterators, else no iterators are invalidated.
Only the iterators to the erased elements are invalidated.
If capacity exceeded or if insert position is not at the front or back, invalidates all iterators, else no iterators are invalidated.
If erasing at either end, only iterators to elements erased are invalidated, else all iterators are invalidated.
If capacity exceeded invalidates all iterators, else iterators to any erased elements are invalidated.
Invalidates all iterators.
Iterators remain valid, but they now point into the swapped container.
The index operator is range checked just like the at() method.