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std::unordered_multiset<Key,Hash,KeyEqual,Allocator>:: insert_range

From cppreference.net

template < container-compatible-range < value_type > R >
void insert_range ( R && rg ) ;
(since C++23)
(constexpr since C++26)

Inserts a copy of each element in the range rg .

Each iterator in the range rg is dereferenced exactly once.

If any of the following conditions is satisfied, the behavior is undefined:

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

Parameters

rg - a container compatible range , that is, an input_range whose elements are convertible to T

Complexity

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

Notes

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

Example

#include <iostream>
#include <unordered_set>
void println(auto, const auto& container)
{
    for (const auto& elem : container)
        std::cout << elem << ' ';
    std::cout << '\n';
}
int main()
{
    auto container = std::unordered_multiset{1, 3, 2, 4};
    const auto rg = {-1, 3, -2};
#ifdef __cpp_lib_containers_ranges
    container.insert_range(rg);
#else
    container.insert(rg.begin(), rg.end());
#endif
    println("{}", container);
}

Possible output:

1 -2 3 3 2 -1 4

See also

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