<deque>

namespace std {
template<class T, class A>
    class deque;
//    TEMPLATE FUNCTIONS
template<class T, class A> 
    bool operator==(
        const deque<T, A>& lhs,
        const deque<T, A>& rhs);
template<class T, class A>
    bool operator!=(
        const deque<T, A>& lhs,
        const deque<T, A>& rhs);
template<class T, class A>
    bool operator<(
        const deque<T, A>& lhs,
        const deque<T, A>& rhs);
template<class T, class A>
    bool operator>(
        const deque<T, A>& lhs,
        const deque<T, A>& rhs);
template<class T, class A>
    bool operator<=(
        const deque<T, A>& lhs,
        const deque<T, A>& rhs);
template<class T, class A>
    bool operator>=(
        const deque<T, A>& lhs,
        const deque<T, A>& rhs);
template<class T, class A>
    void swap(
        const deque<T, A>& lhs,
        const deque<T, A>& rhs);
    };

Include the STL standard header <deque> to define the container template class deque and three supporting templates.