std::multiset::clear(3)

🌸 NAME 🌸

Okay so, bestie, this is std::multiset::clear(3) from the C++ Standard Libary manual, section 3, and the NAME line is lowkey just std::multiset::clear - std::multiset::clear — which is giving “I am the moment, I am the brand” 👑✨

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✨ Synopsis ✨

void clear();  (noexcept since C++11)

It erases all elements from the container. After this call, size() returns zero. Periodt 💅

It also invalidates any references, pointers, and iterators referring to contained elements. Any past-the-end iterator remains valid. So like… the end iterator is safe, but the element-havers are NOT 😭

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🎀 Parameters 🎀

(none) — it takes absolutely nothing, she works alone, main character energy fr fr 🦋

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🫶 Return value 🫶

(none) — also nothing. No return, no drama, just vibes and deletion 💀

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🔥 Complexity 🔥

Linear in the size of the container, i.e., the number of elements. That’s the whole complexity tea ☕✨

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🎬 Example 🎬

Run this code, bestie:

// Run this code

#include <iostream>
#include <string_view>
#include <set>

void print_info(std::string_view rem, const std::multiset<int>& v)
{
    std::cout << rem << "{ ";
    for (const auto& value : v)
        std::cout << value << ' ';
    std::cout << "}\n";
    std::cout << "Size=" << v.size() << '\n';
}

int main()
{
    std::multiset<int> container{1, 2, 3};
    print_info("Before clear: ", container);
    container.clear();
    print_info("After clear: ", container);
}

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📤 Output 📤

Before clear: { 1 2 3 }
Size=3
After clear: { }
Size=0

Not the size going from 3 to 0 😭 she really said “clear” and cleared 💅✨

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😭 Defect reports 😭

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

• DR: LWG 224 · Applied to: C++98 · Behavior as published: the complexity was log(size()) + N, but N was not defined · Correct behavior: corrected to 'linear in size()' 🫶

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👀 See also 👀

• erase — erases elements (public member function) 🧚

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Source: http://cppreference.com · version/date: 2024.06.10 · page: std::multiset::clear(3) — okay bye bestie, stay slaying and keep those past-the-end iterators valid 🌈💜✨