explicit deque(const A& al = A());
explicit deque(size_type n, const T& v = T(), const A& al = A());
deque(const deque& x);
deque(const_iterator first, const_iterator last, const A& al = A());
All constructors store the allocator object al (or, for the copy constructor, x.get_allocator()) in allocator and
initialize the controlled sequence. The first constructor specifies an empty initial controlled sequence. The second
constructor specifies a repetition of n elements of value x. The third constructor specifies a copy of the sequence
controlled by x. The last constructor specifies the sequence [first, last).
In this implementation, if a translator does not support member template functions, the template:
template<class InIt>
deque(InIt first, InIt last, const A& al = A());
is replaced by:
deque(const_iterator first, const_iterator last, const A& al = A());