std::unordered_multiset::emplace

C++

Language

Headers

Freestanding and hosted implementations

Named requirements

Language support library

Concepts library (C++20)

Diagnostics library

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Filesystem library (C++17)

Technical Specifications

Containers library

array (C++11)

vector

deque

forward_list (C++11)

list

set

multiset

map

multimap

unordered_set (C++11)

unordered_multiset (C++11)

unordered_map (C++11)

unordered_multimap (C++11)

stack

queue

priority_queue

span (C++20)

std::unordered_multiset

Member functions

unordered_multiset::unordered_multiset

unordered_multiset::~unordered_multiset

unordered_multiset::operator=

unordered_multiset::get_allocator

Iterators

unordered_multiset::beginunordered_multiset::cbegin

unordered_multiset::endunordered_multiset::cend

Capacity

unordered_multiset::erase

unordered_multiset::size

unordered_multiset::max_size

Modifiers

unordered_multiset::clear

unordered_multiset::insert

unordered_multiset::emplace

unordered_multiset::emplace_hint

unordered_multiset::erase

unordered_multiset::swap

unordered_multiset::extract (C++17)

unordered_multiset::merge (C++17)

Lookup

unordered_multiset::count

unordered_multiset::find

unordered_multiset::contains (C++20)

unordered_multiset::equal_range

Bucket interface

unordered_multiset::begin(size_type)unordered_multiset::cbegin(size_type)

unordered_multiset::end(size_type)unordered_multiset::cend(size_type)

unordered_multiset::bucket_count

unordered_multiset::max_bucket_count

unordered_multiset::bucket_size

unordered_multiset::bucket

Hash policy

unordered_multiset::load_factor

unordered_multiset::max_load_factor

unordered_multiset::rehash

unordered_multiset::reserve

Observers

unordered_multiset::hash_function

unordered_multiset::key_eq

Deduction guides(C++17)

template< class... Args > iterator emplace( Args&&... args );		(since C++11)

Inserts a new element into the container constructed in-place with the given args .

Careful use of emplace allows the new element to be constructed while avoiding unnecessary copy or move operations. The constructor of the new element is called with exactly the same arguments as supplied to emplace, forwarded via std::forward<Args>(args)....

If rehashing occurs due to the insertion, all iterators are invalidated. Otherwise iterators are not affected. References are not invalidated. Rehashing occurs only if the new number of elements is greater than max_load_factor()*bucket_count().

Parameters

args

-

arguments to forward to the constructor of the element

Return value

Returns an iterator to the inserted element.

Exceptions

If an exception is thrown by any operation, this function has no effect.

Complexity

Amortized constant on average, worst case linear in the size of the container.

See also

emplace_hint	constructs elements in-place using a hint (public member function)
insert	inserts elements or nodes (since C++17) (public member function)