explicit deque(const Allocator& = Allocator());
Effects: Constructs an empty deque, using the specified allocator.
Complexity: Constant.
Effects: Constructs a deque with n value-initialized elements.
Requires: T shall be DefaultConstructible.
Complexity: Linear in n.
deque(size_type n, const T& value,
const Allocator& = Allocator());
Effects: Constructs a deque with n copies of value, using the specified allocator.
Requires: T shall be CopyInsertable into *this.
Complexity: Linear in n.
template <class InputIterator>
deque(InputIterator first, InputIterator last,
const Allocator& = Allocator());
Effects: Constructs a deque equal to the range [first,last), using the specified allocator.
Complexity: distance(first, last).
template <class InputIterator>
void assign(InputIterator first, InputIterator last);
Effects:
erase(begin(), end()); insert(begin(), first, last);
void assign(size_type n, const T& t);
Effects:
erase(begin(), end()); insert(begin(), n, t);