26 Containers library [containers]

26.5 Unordered associative containers [unord]

26.5.6 Class template unordered_­set [unord.set]

26.5.6.3 unordered_­set swap [unord.set.swap]

template <class Key, class Hash, class Pred, class Alloc> void swap(unordered_set<Key, Hash, Pred, Alloc>& x, unordered_set<Key, Hash, Pred, Alloc>& y) noexcept(noexcept(x.swap(y)));

Effects: As if by x.swap(y).