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std::unorde...nsert_range(3)   C++ Standard Libary  std::unorde...nsert_range(3)

NAME
     std::unordered_map::insert_range - std::unordered_map::insert_range

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

	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. 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  invali-
     dated. 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_map  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(NA.(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_map{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:
      {4,44} {-1,-11} {2,22} {3,33} {-2,-22} {1,11}

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

http://cppreference.com 	   2024.06.10	    std::unorde...nsert_range(3)
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