std::atomic_ref::fetch_min(3)

💅 std::atomic_ref::fetch_min(3)

okay bestie, welcome to the manual page for std::atomic_ref::fetch_min, straight out of the C++ Standard Library section of the docs 🎀 this one's a new-ish little icon, so let's get into it ✨

---

🌸 NAME

std::atomic_ref::fetch_min — literally std::atomic_ref::fetch_min, bestie, the name tells you the whole story 💖

---

⭐ SYNOPSIS

so there's two flavors of this, and you only get one or the other depending on your specialization 👑

       member only of atomic_ref<Integral > specializations
       T fetch_min( T arg, std::memory_order order =
                               std::memory_order_seq_cst ) const
    (1) (since C++26)
       noexcept;
       member only of atomic_ref<T*> partial specialization
       T* fetch_min( T* arg, std::memory_order order =
                                 std::memory_order_seq_cst ) const
    (2) (since C++26)
       noexcept;

ngl, both of these are noexcept and both are since C++26 — so if you're on an older standard, this is giving "not yet, babe" 😭

---

💜 DESCRIPTION

okay so the vibe here: it atomically replaces the current value of the referenced object with the result of std::min of the value and arg. that's it, that's the whole thing — it performs an atomic minimum operation 🦋

and like, it's not just a read or just a write — it's a full read-modify-write operation. the memory is affected according to the value of order, so keep your eyes on that parameter, iykyk 💅

2) now for the pointer version — this is the part where you gotta be careful, bestie 🫶 if the pointers point to different complete objects (or subobjects thereof), then pointer comparison does not establish a strict weak ordering. so like, don't be out here comparing pointers to totally unrelated things and expecting a sensible answer, fr fr 💀

---

✨ PARAMETERS

• arg — the other argument of std::min 🍓 (yes, that's really all it is)
• order — the memory order constraints to enforce, aka the rules of the game 🔥

---

💖 RETURN VALUE

it hands you back the value that was immediately preceding the effects of this function in the modification order of *this 👑 so like, the "before" picture, if the "before" picture were a value in a modification order. slay.

---

🧚 NOTES

feature-test macro time, bestie — here's the one you're looking for 🌈

• __cpp_lib_atomic_min_max — value 202403L — standard (C++26) — feature: Atomic minimum/maximum ⭐

that's your "am I allowed to use this" check, periodt 💅

---

🙈 EXAMPLE

This section is incomplete Reason: no example

not me finding a page with no example 😭 the docs really said "figure it out yourself" 💀

---

🎀 CATEGORY

• Todo no example

---

and that's the whole page, bestie!! 🫶 this gem came to you from http://cppreference.com, version 2024.06.10, dated 2024.06.10 — go forth and atomically minimum your way through C++26 💖✨🌸