namespace std {
namespace tr1 {
// DECLARATIONS
template <class Key, class Hash, class Pred, class Alloc>
class unordered_set;
template <class Key, class Hash, class Pred, class Alloc>
class unordered_multiset;
// TEMPLATE FUNCTIONS
template <class Key, class Hash, class Pred, class Alloc>
void swap(
unordered_set<Key, Hash, Pred, Alloc>& left,
unordered_set<Key, Hash, Pred, Alloc>& right);
template <class Key, class Hash, class Pred, class Alloc>
void swap(
unordered_multiset<Key, Hash, Pred, Alloc>& left,
unordered_multiset<Key, Hash, Pred, Alloc>& right);
} // namespace tr1
} // namespace std