deque class is used for the operations on a double ended queue.
A deque class is declared as:
template <class T, class Allocator = allocator<T>> class deque
Types of deque constructors:
Type-1: Empty deque
explicit deque(const Allocator &a = Allocator( ) );
Type-2: Deque that has x elements and values y.
explicit deque(size_type x, const T &y = T ( ), const Allocator &a = Allocator( ));
Type-3: Deque having same elements as obj
deque(const deque<T, Allocator> &obj);
Types of deque operators: ==, <, <=, !=, >, >=