std::unordered_multimap<Key,T,Hash,KeyEqual,Allocator>::insert_range
From cppreference.com
< cpp | container | unordered multimap
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.
Contents |
[edit] Parameters
rg | - | a container compatible range, that is, an input_range whose elements are convertible to T
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Type requirements | ||
-value_type must be EmplaceConstructible into unordered_multimap from *ranges::begin(rg). Otherwise, the behavior is undefined.
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[edit] Return value
(none)
[edit] Complexity
Average case O(N), where N is ranges::distance(rg), worst case O(N·(a.size() + 1)).
[edit] Notes
Feature-test macro | Value | Std | Feature |
---|---|---|---|
__cpp_lib_containers_ranges |
202202L |
(C++23) | Ranges-aware construction and insertion |
[edit] 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}
[edit] See also
inserts elements or nodes(since C++17) (public member function) |