std::unordered_multimap<Key,T,Hash,KeyEqual,Allocator>::rehash

 

C++

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Feature test macros (C++20)

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Symbols index

External libraries

 

Containers library

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array (C++11)

vector

vector<bool>

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forward_list (C++11)

list

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set

multiset

map

multimap

Unordered associative

unordered_set (C++11)

unordered_multiset (C++11)

unordered_map (C++11)

unordered_multimap (C++11)

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stack

queue

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flat_set (C++23)

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flat_multimap (C++23)

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span (C++20)

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Iterator invalidation

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std::unordered_multimap

Member types

Member functions

unordered_multimap::~unordered_multimap

unordered_multimap::operator=

unordered_multimap::get_allocator

Iterators

unordered_multimap::beginunordered_multimap::cbegin

unordered_multimap::endunordered_multimap::cend

Capacity

unordered_multimap::empty

unordered_multimap::size

unordered_multimap::max_size

Modifiers

unordered_multimap::clear

unordered_multimap::insert

unordered_multimap::insert_range (C++23)

unordered_multimap::emplace

unordered_multimap::emplace_hint

unordered_multimap::erase

unordered_multimap::swap

unordered_multimap::extract (C++17)

unordered_multimap::merge (C++17)

Lookup

unordered_multimap::count

unordered_multimap::find

unordered_multimap::contains (C++20)

unordered_multimap::equal_range

Bucket interface

unordered_multimap::begin(size_type)unordered_multimap::cbegin(size_type)

unordered_multimap::end(size_type)unordered_multimap::cend(size_type)

unordered_multimap::bucket_count

unordered_multimap::max_bucket_count

unordered_multimap::bucket_size

unordered_multimap::bucket

Hash policy

unordered_multimap::load_factor

unordered_multimap::max_load_factor

unordered_multimap::rehash

unordered_multimap::reserve

Observers

unordered_multimap::hash_function

unordered_multimap::key_eq

Non-member functions

operator==operator!= (until C++20)

std::swap

erase_if (C++20)

Deduction guides(C++17)

 

void rehash( size_type count );		(since C++11)

Changes the number of buckets to a value n that is not less than count and satisfies n >= size() / max_load_factor(), then rehashes the container, i.e. puts the elements into appropriate buckets considering that total number of buckets has changed.

Parameters

count

-

lower bound for the new number of buckets

Return value

(none)

Complexity

Average case linear in the size of the container, worst case quadratic.

Notes

rehash(0) may be used to force an unconditional rehash, such as after suspension of automatic rehashing by temporarily increasing max_load_factor().

See also

reserve (C++11)

reserves space for at least the specified number of elements and regenerates the hash table (public member function)