26 Containers library [containers]

26.5 Unordered associative containers [unord]

26.5.4 Class template unordered_­map [unord.map]

26.5.4.5 unordered_­map swap [unord.map.swap]

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

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