std::unorde...insert_range(3)

💖 NAME 💖

okay so this page is std::unordered_multiset::insert_range — and the NAME line literally says std::unordered_multiset::insert_range - std::unordered_multiset::insert_range, because why not repeat the icon herself 💅. The manual is C++ Standard Libary (spelling and all), and the page tag is std::unorde...insert_range(3). She’s a C++23 girlie: insert_range copies a whole range into your multiset, and honestly? obsessed. 💖

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✨ 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. Like, every single one gets copied in. 🫶

Each iterator in the range rg is dereferenced exactly once. The behavior is undefined if rg overlaps with the container — no cap, do not do that, that’s the dangerous girlie behavior 😭.

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. So yeah: rehash = iterator vibe check failed 💀.

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🎀 Parameters 🎀

• rg — a container compatible range, that is, an input_range whose elements are convertible to T. Basically a range that’s compatible with the container, bestie ✨.

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🦋 Type requirements 🦋

• value_type must be EmplaceConstructible into unordered_multiset from *ranges::begin(rg). Otherwise, the behavior is undefined. UNDEFINED, bestie — we do not play with that 🙈.

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🌸 Return value 🌸

(none) — nothing, nada, zero returns. She just does the thing and leaves 💅.

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⭐ Complexity ⭐

Average case O(N), where N is ranges::distance(rg), worst case O(N·(a.size() + 1)). Math girlie said what she said 🧚.

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🌈 Notes 🌈

Feature-test macro table, but make it cute:

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

iykyk 👑.

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🍓 Example 🍓

Run this code 👇

#include <iostream>
#include <unordered_set>

void println(auto, auto const& 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);
}

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👑 Possible output 👑

1 -2 3 3 2 -1 4

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👀 See also 👀

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

yep, those are the See also crumbs — preserved exactly, periodt 💜.

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mwah 💋 — source/version: http://cppreference.com, dated 2024.06.10, page tag std::unorde...insert_range(3). That’s the whole footer, bestie 🫶.