std::atomic...or_explicit(3)

🎀 NAME 🎀

std::atomic_fetch_xor,std::atomic_fetch_xor_explicit - std::atomic_fetch_xor,std::atomic_fetch_xor_explicit — that’s the NAME line, bestie. This page is from the C++ Standard Libary manual, and the header title folded in up here is std::atomic...or_explicit(3). ✨

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✨ Synopsis ✨

Defined in header <atomic>
template< class T >

T atomic_fetch_xor( std::atomic<T>* obj,
(1) (since C++11)

                        typename std::atomic<T>::value_type arg )
noexcept;
template< class T >

T atomic_fetch_xor( volatile std::atomic<T>* obj,
(2) (since C++11)

                        typename std::atomic<T>::value_type arg )
noexcept;
template< class T >

T atomic_fetch_xor_explicit( std::atomic<T>* obj,
                             typename std::atomic<T>::value_type
(3) (since C++11)
arg,

                             std::memory_order order) noexcept;
template< class T >

T atomic_fetch_xor_explicit( volatile std::atomic<T>* obj,
                             typename std::atomic<T>::value_type
(4) (since C++11)
arg,

                             std::memory_order order) noexcept;

okay so what it does: it atomically replaces the value pointed by obj with the result of bitwise XOR between the old value of obj and arg. Then it returns the value obj held previously. 💅

The operation is performed as if the following is executed:

1,2) obj->fetch_xor(arg)
3,4) obj->fetch_xor(arg, order)

🚨 IMPORTANT, bestie: if std::atomic<T> has no fetch_xor member (this member is only provided for integral types except bool), the program is ill-formed. No cap.

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🌸 Parameters 🌸

• obj — pointer to the atomic object to modify.
• arg — the value to bitwise XOR to the value stored in the atomic object.
• order — the memory synchronization ordering.

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💖 Return value 💖

The value immediately preceding the effects of this function in the modification order of *obj. That’s the previous value, bestie. 🫶

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🦋 Example 🦋

This section is incomplete Reason: no example

😭 literally what the page says — not me being lazy.

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🧚 Defect reports 🧚

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

• DR: P0558R1
  • Applied to: C++11
  • Behavior as published: exact type match was required because T is only deduced from multiple arguments
  • Correct behavior: T was deduced from obj

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👀 See also 👀

• fetch_xor — atomically performs bitwise XOR between the argument and the value of the atomic object and obtains the value held previously (public member function of std::atomic<T>).
• atomic_fetch_or (C++11), atomic_fetch_or_explicit (C++11) — replaces the atomic object with the result of bitwise OR with a non-atomic argument and obtains the previous value of the atomic (function template).
• atomic_fetch_and (C++11), atomic_fetch_and_explicit (C++11) — replaces the atomic object with the result of bitwise AND with a non-atomic argument and obtains the previous value of the atomic (function template).
• C documentation for atomic_fetch_xor, atomic_fetch_xor_explicit.

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🏷️ Category 🏷️

• Todo no example

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🫶 That’s the whole page, bestie. Source/version/date sign-off: http://cppreference.com · 2024.06.10 · std::atomic...or_explicit(3). Periodt. 💖