std::set::insert_range(3)

💖 NAME 💖

okay bestie, welcome to the std::set::insert_range(3) page from the C++ Standard Libary manual — yep, Libary is exactly how it's spelled up there and I am leaving it alone, no cap. The name is literally std::set::insert_range — std::set::insert_range. That's the whole NAME section, and it's already iconic. 💅

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✨ Synopsis ✨

This is the glow-up that landed in C++23:

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

okay so what it actually does: it 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. No iterators or references are invalidated. Periodt.

⚠️ the behavior is undefined if rg overlaps with the container. That's the dangerous bit, bestie — do not do the overlap thing. 🙈

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🌸 Parameters 🌸

• rg — a container compatible range, that is, an input_range whose elements are convertible to T. That's the whole parameter section and it ate. 💅

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🦋 Type requirements 🦋

• value_type must be EmplaceConstructible into set from *ranges::begin(rg). Otherwise, the behavior is undefined. 😭

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🎀 Return value 🎀

• (none)

It returns nothing, bestie. It just does the thing and keeps it moving. 🫶

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🔥 Complexity 🔥

The cost is N·log(a.size() + N), where N is ranges::distance(rg). That's the whole formula — don't misplace a parenthesis, iykyk. 🧚

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⭐ Notes ⭐

Feature-test macro tea:

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

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🌈 Example 🌈

// Run this code — yes, that's the label, and here's the code exactly:

// Run this code

#include <iostream>
#include <set>

void println(auto, auto const& container)
{
    for (const auto& elem : container)
        std::cout << elem << ' ';
    std::cout << '\n';
}

int main()
{
    auto container = std::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);
}

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💜 Output 💜

-2 -1 1 2 3 4

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👑 See also 👑

The source prints insert or nodes with (since C++17) and (public member function) attached, so here's the whole See also situation:

• insert — inserts elements
• or nodes — (since C++17) — (public member function) — the source line is insert or nodes, so that's the exact tea. 🍓

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mwah 💋 source/version/date, all preserved: http://cppreference.com, 2024.06.10, and std::set::insert_range(3). bye bestie, go insert a range responsibly 🫶