<set>

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

Include the STL standard header <set> to define the container template classes set and multiset, and their supporting templates.