std::flat_m...map::replace(3)

okay so this is the std::flat_m...map::replace(3) page — folded in from the C++ Standard Libary manual — and bestie, we are about to make replacing your underlying containers feel like a main-character move. 💅✨

---

🌸 NAME 🌸

std::flat_multimap::replace — that's the name, and the name is std::flat_multimap::replace. No plot twist, just a member function ready to swap your underlying containers. 💅

---

✨ Synopsis ✨

Here's the whole vibe — this one is since C++23:

void replace( key_container_type&& key_cont, mapped_container_type&& mapped_cont );

It replaces the underlying containers c. Equivalent to:

c.keys = std::move(key_cont);
c.values = std::move(mapped_cont);

The following conditions must be met:

• The expression key_cont.size() == mapped_cont.size() is true,
• The elements of key_cont are sorted with respect to compare.

🚨 Otherwise, the behavior is undefined. Not "maybe fine", not "we'll see" — undefined. Protect your peace and your program, bestie.

---

🎀 Parameters 🎀

• keys_cont — a sorted keys container of type KeyContainer; its contents will be moved into *this. 🫶
• mapped_cont — a container of mapped values of type MappedContainer; its contents will be moved into *this. 💖

---

🦋 Return value 🦋

(none). That's it. No return, no drama. 🎀

---

🔥 Complexity 🔥

Equals to complexity of std::move applied to adapted containers. That's the whole sentence — we're not adding lore. 💀

---

🌈 Example 🌈

// Run this code

#include <algorithm>
#include <cassert>
#include <flat_map>
#include <print>
#include <vector>

int main()
{
    std::vector<int> keys{1, 2, 3};
    assert(std::ranges::is_sorted(keys));
    std::vector<double> values{2.2, 3.3, 1.1};
    assert(keys.size() == values.size());

    std::flat_multimap<int, double> map;
    assert(map.empty());

    map.replace(keys, values);
    assert(map.size() == 3);
    assert(map.keys() == 3);
    assert(map.values() == 3);
    assert(keys.empty());
    assert(values.empty());

    std::println("{}", map);
}

🍓 Output 🍓

{1: 2.2, 2: 3.3, 3: 1.1}

---

👑 See also 👑

• extract — extracts the underlying containers (public member function). 🔥

---

cute sign-off: source/version is http://cppreference.com, date is 2024.06.10, page is std::flat_m...map::replace(3). mwah 💋🫶