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

 

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std::unordered_set

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unordered_set::unordered_set unordered_set::~unordered_set unordered_set::operator= unordered_set::get_allocator Iterators unordered_set::beginunordered_set::cbegin unordered_set::endunordered_set::cend Capacity unordered_set::size unordered_set::max_size unordered_set::empty Modifiers unordered_set::clear unordered_set::erase unordered_set::swap unordered_set::extract (C++17) unordered_set::merge (C++17) unordered_set::insert unordered_set::insert_range (C++23)   unordered_set::emplace unordered_set::emplace_hint	Lookup unordered_set::count unordered_set::find unordered_set::contains (C++20) unordered_set::equal_range Bucket interface unordered_set::begin(size_type)unordered_set::cbegin(size_type) unordered_set::end(size_type)unordered_set::cend(size_type) unordered_set::bucket_count unordered_set::max_bucket_count unordered_set::bucket_size unordered_set::bucket Hash policy unordered_set::load_factor unordered_set::max_load_factor unordered_set::rehash unordered_set::reserve Observers unordered_set::hash_function unordered_set::key_eq
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operator==operator!= (until C++20)	std::swap(std::unordered_set) erase_if(std::unordered_set) (C++20)
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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 if and only if there is no element with key equivalent to the key of that element in *this.

Each iterator in the range rg is dereferenced exactly once.

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

• value_type is not EmplaceConstructible into unordered_set from *ranges::begin(rg)
• rg and *this overlap.

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

Complexity

Average case \(\scriptsize N\)N, worst case \(\scriptsize O(N \cdot S + N)\)O(N·S+N), where \(\scriptsize S\)S is size() and \(\scriptsize N\)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

Run this code

#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_set{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:

4 -1 2 3 -2 1

See also

insert

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