26 Containers library [containers]

26.5 Unordered associative containers [unord]

26.5.5 Class template unordered_­multimap [unord.multimap]

26.5.5.4 unordered_­multimap swap [unord.multimap.swap]

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

Effects: Как будто мимо x.swap(y).