std::unorde...ltiset::find(3)

💖 NAME 💖

std::unordered_multiset::find — bestie, it's literally std::unordered_multiset::find, that's the whole name, no notes 💅

This one lives in the C++ Standard Libary manual, and the page itself is std::unorde...ltiset::find(3) (yes the title is truncated with dots, she's mysterious like that ✨).

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✨ Synopsis ✨

okay so here's the whole menu, look at her go:

iterator find( const Key& key );             (1) (since C++11)
const_iterator find( const Key& key ) const; (2) (since C++11)
template< class K >                          (3) (since C++20)
iterator find( const K& x );
template< class K >                          (4) (since C++20)
const_iterator find( const K& x ) const;

• (1), (2) — these two look for an element whose key is equivalent to key. ⚠️ And here's the tea: if the container has several elements with the key you asked for, any of them may be returned. Not the first, not the last, any. So don't get attached to a specific one, bestie 😭
• (3), (4) — these look for an element whose key compares equivalent to the value x. But she's picky about showing up: this overload only participates in overload resolution if Hash::is_transparent and KeyEqual::is_transparent are both valid and each denotes a type. 👑 This assumes that such Hash is callable with both K and Key type, and that the KeyEqual is transparent — and together? That's what lets you call this function without constructing an instance of Key. No cap, that's the whole point, that's the vibe 🦋

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🎀 Parameters 🎀

• key — the key value of the element you're searching for 🔍
• x — a value of any type that can be transparently compared with a key ✨

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🌸 Return value 🌸

An iterator to the element you requested, periodt. 💅

But if no such element is found? You get the past-the-end iterator (go peek at end(), she's right there) 🫶

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🔥 Complexity 🔥

• Constant on average ⭐
• Worst case linear in the size of the container 💀

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🧚 Notes 🧚

There's a feature-test macro for the heterogeneous girlies, and here's the whole row, not a single crumb left out:

• Feature-test macro: __cpp_lib_generic_unordered_lookup
• Value: 201811L
• Std: (C++20)
• Feature: Heterogeneous comparison lookup in unordered associative containers; overloads (3,4) 👑

iykyk 🌈

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🍓 Example 🍓

// Run this code

#include <iostream>
#include <unordered_set>

int main()
{
    // Simple comparison demo.
    std::unordered_multiset<int> example = {1, 2, 3, 4};

    if (auto search = example.find(2); search != example.end())
        std::cout << "Found " << (*search) << '\n';
    else
        std::cout << "Not found\n";
}

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🌈 Output 🌈

Found 2

she ate, honestly 👑

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💜 See also 💜

• count — returns the number of elements matching a specific key (public member function) 🧮
• equal_range — returns range of elements matching a specific key (public member function) 📏

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okay that's the whole page, mwah 💋 — sourced straight from http://cppreference.com, dated 2024.06.10, and it's the std::unorde...ltiset::find(3) page, go forth and find your elements bestie 🦋✨🎀