std::swap(std::unordered_set)

 

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std::unordered_set

Member types
Member functions
unordered_set::unordered_set unordered_set::~unordered_set unordered_set::operator= unordered_set::get_allocator Iterators unordered_set::beginunordered_set::cbegin unordered_set::endunordered_set::cend Capacity unordered_set::size unordered_set::max_size unordered_set::empty Modifiers unordered_set::clear unordered_set::erase unordered_set::swap unordered_set::extract (C++17) unordered_set::merge (C++17) unordered_set::insert unordered_set::insert_range (C++23)   unordered_set::emplace unordered_set::emplace_hint	Lookup unordered_set::count unordered_set::find unordered_set::contains (C++20) unordered_set::equal_range Bucket interface unordered_set::begin(size_type)unordered_set::cbegin(size_type) unordered_set::end(size_type)unordered_set::cend(size_type) unordered_set::bucket_count unordered_set::max_bucket_count unordered_set::bucket_size unordered_set::bucket Hash policy unordered_set::load_factor unordered_set::max_load_factor unordered_set::rehash unordered_set::reserve Observers unordered_set::hash_function unordered_set::key_eq
Non-member functions
operator==operator!= (until C++20)	std::swap(std::unordered_set) erase_if(std::unordered_set) (C++20)
Deduction guides(C++17)

 

Defined in header <unordered_set>
template<class Key, class Hash, class KeyEqual, class Alloc > void swap(std::unordered_set<Key, Hash, KeyEqual, Alloc>& lhs,            std::unordered_set<Key, Hash, KeyEqual, Alloc>& rhs );		(since C++11) (until C++17)
template<class Key, class Hash, class KeyEqual, class Alloc > void swap(std::unordered_set<Key, Hash, KeyEqual, Alloc>& lhs,            std::unordered_set<Key, Hash, KeyEqual, Alloc>& rhs )                noexcept(/* see below */);		(since C++17)

Specializes the std::swap algorithm for std::unordered_set. Swaps the contents of lhs and rhs. Calls lhs.swap(rhs).

Parameters

lhs, rhs

-

containers whose contents to swap

Return value

(none)

Complexity

Constant.

Exceptions

noexcept specification:   noexcept(noexcept(lhs.swap(rhs)))

(since C++17)

Example

Run this code

#include <algorithm>#include <iostream>#include <unordered_set>   int main(){std::unordered_set<int> alice{1, 2, 3};std::unordered_set<int> bob{7, 8, 9, 10};   auto print =[](constint& n){std::cout<<' '<< n;};   // Print state before swapstd::cout<<"Alice:";std::for_each(alice.begin(), alice.end(), print);std::cout<<"\nBobby:";std::for_each(bob.begin(), bob.end(), print);std::cout<<'\n';   std::cout<<"-- SWAP\n";std::swap(alice, bob);   // Print state after swapstd::cout<<"Alice:";std::for_each(alice.begin(), alice.end(), print);std::cout<<"\nBobby:";std::for_each(bob.begin(), bob.end(), print);std::cout<<'\n';}

Possible output:

Alice: 1 2 3 Bobby: 7 8 9 10 -- SWAP Alice: 7 8 9 10 Bobby: 1 2 3

See also

swap	swaps the contents (public member function)