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std::map<Key,T,Compare,Allocator>::insert_range

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Revision as of 01:44, 7 August 2023 by Space Mission (Talk | contribs)

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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 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.

No iterators or references are invalidated.

Contents

[edit] 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 map from *ranges::begin(rg). Otherwise, the behavior is undefined.

[edit] Return value

(none)

[edit] Complexity

N·log(a.size() + N), where 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

#include <iostream>
#include <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::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);
}

Output:

{-2,-22} {-1,-11} {1,11} {2,22} {3,33} {4,44}

[edit] See also

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