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

 

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std::unordered_multimap

Member types
Member functions
unordered_multimap::unordered_multimap 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::size unordered_multimap::max_size unordered_multimap::empty 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
std::swap(std::unordered_multimap) erase_if(std::unordered_multimap) (C++20)	operator==operator!= (until C++20)
Deduction guides (C++17)

 

template< container-compatible-range<value_type> R > void insert_range( R&& rg );		(since C++23)

Inserts a copy of each element in the range rg.

Each iterator in the range rg is dereferenced exactly once. The behavior is undefined if rg overlaps with the container.

If after the operation the new number of elements is greater than old max_load_factor() * bucket_count() a rehashing takes place.
If rehashing occurs (due to the insertion), all iterators are invalidated. Otherwise (no rehashing), iterators are not invalidated.

Parameters

rg	-	a container compatible range, that is, an input_range whose elements are convertible to T
Type requirements
- value_type must be EmplaceConstructible into unordered_multimap from *ranges::begin(rg). Otherwise, the behavior is undefined.

Return value

(none)

Complexity

Average case O(N), where N is ranges::distance(rg), worst case O(N·(a.size() + 1)).

Notes

Feature-test macro	Value	Std	Feature
__cpp_lib_containers_ranges	202202L	(C++23)	Ranges-aware construction and insertion

Example

Run this code

#include <iostream>
#include <unordered_map>
#include <utility>
 
void println(auto, auto const& container)
{
    for (const auto& [key, value] : container)
        std::cout << '{' << key << ',' << value << '}' << ' ';
    std::cout << '\n';
}
 
int main()
{
    auto container = std::unordered_multimap{std::pair{1, 11}, {3, 33}, {2, 22}, {4, 44}};
    const auto rg = {std::pair{-1, -11}, {3, -33}, {-2, -22}};
#ifdef __cpp_lib_containers_ranges
    container.insert_range(rg);
#else
    container.insert(rg.begin(), rg.end());
#endif
    println("{}", container);
}

Possible output:

{1,11} {-2,-22} {3,-33} {3,33} {2,22} {-1,-11} {4,44}

See also

insert

inserts elements or nodes(since C++17) (public member function)