std::set::key_comp(3)

👑 std::set::key_comp — from the C++ Standard Libary manual 💅

okay bestie, welcome to the std::set::key_comp page ✨ this is the C++ Standard Libary manual showing up with main character energy, and we’re gonna get you comfy with this member function fr fr.

🌸 NAME 🌸

std::set::key_comp - std::set::key_comp

✨ Synopsis ✨

key_compare key_comp() const;

This returns the function object that compares the keys — it’s a copy of this container’s constructor argument comp 🫶. It is the same as value_comp 💖.

🎀 Parameters 🎀

(none) — literally zero parameters, bestie. She takes nothing 😌.

💖 Return value 💖

The key comparison function object. That’s the whole vibe ✨.

🧚 Complexity 🧚

Constant. Periodt. ⭐

🔥 Example 🔥

// Run this code

#include <iostream>
#include <set>
#include <utility>

// Example module 97 key compare function
struct ModCmp
{
    bool operator()(int lhs, int rhs) const
    {
        return (lhs % 97) < (rhs % 97);
    }
};

int main()
{
    std::set<int, ModCmp> cont{1, 2, 3, 4, 5};

    auto comp_func = cont.key_comp();

    for (const int key : cont)
    {
        const bool before = comp_func(key, 100);
        const bool after = comp_func(100, key);

        std::cout << '(' << key << ") ";
        if (!before && !after)
            std::cout << "equivalent to key (100)\n";
        else if (before)
            std::cout << "goes before key (100)\n";
        else if (after)
            std::cout << "goes after key (100)\n";
        else
            std::unreachable();
    }
}

⭐ Output ⭐

Key (1) goes before key (100)
Key (2) goes before key (100)
Key (3) equivalent to key (100)
Key (4) goes after key (100)
Key (5) goes after key (100)

🦋 See also 🦋

• value_comp — returns the function that compares keys in objects of type value_type (public member function) 💜

made with 💖 from cppreference.com, 2024.06.10, for std::set::key_comp(3) — bye bestie, go compare some keys 🫶🌈