std::flat_set::clear(3)

💅 std::flat_set::clear 💅

okay so welcome to the std::flat_set::clear(3) page — manual name folded in right here: it's from the C++ Standard Libary manual. (Yes, that spelling is what the header says; we're keeping it exactly, bestie.) This is the std::flat_set clear page and it is lowkey iconic: one tiny member, zero drama. 🫶

🌸 NAME 🌸

std::flat_set::clear — std::flat_set::clear. That's the name, no cap. 🎀

✨ Synopsis ✨

void clear() noexcept;  (since C++23)

It erases all elements from the container adaptor. After this call, size() returns zero. Fr fr, that's the whole plot. 💅

🚨 Important vibe check: it invalidates any references, pointers, and iterators referring to contained elements. So don't be out here using old refs after the clear, bestie — they are not giving valid anymore. 😭

🎀 Parameters 🎀

• (none) — no parameters, not even one. 🍓

🦋 Return value 🦋

• (none) — nothing comes back. It's giving void and unbothered. 💜

🔥 Complexity 🔥

Linear in the size of the container adaptor, i.e., the number of elements. So yeah, it scales with how much stuff is in there. 👑

🌈 Example 🌈

Okay so run this code, it's literally the whole before/after glow-up 👇

// Run this code

#include <iostream>
#include <string_view>
#include <flat_set>

void print_info(std::string_view rem, const std::flat_set<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::flat_set<int> container{1, 2, 3};
    print_info("Before clear: ", container);
    container.clear();
    print_info("After clear: ", container);
}

⭐ Output ⭐

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

👑 See also 👑

• erase — erases elements, and it's a public member function. That's the other icon, go check it out. 🎀

Source/version/date sign-off: http://cppreference.com · 2024.06.10 · std::flat_set::clear(3). That's the footer info, folded into this cute little send-off instead of a boring last line. Mwah 💋✨