std::unordered_set<Key,Hash,KeyEqual,Allocator>::insert_range
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< cpp | container | unordered set
C++
Feature test macros (C++20)
Concepts library (C++20)
Metaprogramming library (C++11)
Ranges library (C++20)
Filesystem library (C++17)
Concurrency support library (C++11)
Execution control library (C++26)
Containers library
(C++17)
(C++11)
(C++26)
(C++26)
(C++11)
(C++11)
(C++11)
(C++11)
(C++11)
(C++23)
(C++23)
(C++23)
(C++23)
(C++20)
(C++23)
Tables
std::unordered_set (C++17)
(C++17)
unordered_set::insert_range
(C++23)
(C++20)
(until C++20)
template< container-compatible-range <value_type> R >
void insert_range( R&& rg );
(since C++23) void insert_range( R&& rg );
(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_typeis not EmplaceConstructible intounordered_setfrom *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.
Contents
[edit] Parameters
[edit] 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).
[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_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