Why would I prefer using vector to deque

Question

Since

1. they are both contiguous memory containers;
2. feature wise, deque has almost everything vector has but more, since it is more efficient to insert

Answer 1

Note that vector memory is re-allocated as the array grows. If you have pointers to vector elements, they will become invalid.

Also, if you erase an element, iterators become invalid (but not "for(auto...)").

Edit: changed 'deque' to 'vector'