std::unordered_multiset<Key,Hash,KeyEqual,Allocator>::swap - cppreference.com (original) (raw)
| void swap( unordered_multiset& other ); | | (since C++11) (until C++17) | | -------------------------------------------------------------------- | | ------------------------------------- | | void swap( unordered_multiset& other ) noexcept(/* see below */); | | (since C++17) (constexpr since C++26) |
Exchanges the contents of the container with those of other. Does not invoke any move, copy, or swap operations on individual elements.
All iterators and references remain valid. The end() iterator is invalidated.Hash and KeyEqual must be Swappable, and objects of these types are exchanged using unqualified calls to non-member swap. If std::allocator_traits<allocator_type>::propagate_on_container_swap::value is true, then the allocators are exchanged using an unqualified call to non-member swap. Otherwise, they are not swapped (and if get_allocator() != other.get_allocator(), the behavior is undefined).
[edit] Parameters
| other | - | container to exchange the contents with |
|---|
[edit] Exceptions
[edit] Complexity
Constant.
[edit] Example
#include #include template<class Os, class Co> Os& operator<<(Os& os, const Co& co) { os << '{'; for (const auto& i : co) os << ' ' << i; return os << " } "; } int main() { std::unordered_multiset a1{3, 1, 3, 2}, a2{5, 4, 5}; auto it1 = std::next(a1.begin()); auto it2 = std::next(a2.begin()); const int& ref1 = *(a1.begin()); const int& ref2 = *(a2.begin()); std::cout << a1 << a2 << *it1 << ' ' << *it2 << ' ' << ref1 << ' ' << ref2 << '\n'; a1.swap(a2); std::cout << a1 << a2 << *it1 << ' ' << *it2 << ' ' << ref1 << ' ' << ref2 << '\n'; // Note that every iterator referring to an element in one container before the swap // refers to the same element in the other container after the swap. Same is true // for references. }
Possible output:
{ 2 3 3 1 } { 4 5 5 } 3 5 2 4 { 4 5 5 } { 2 3 3 1 } 3 5 2 4