std::atomic::fetch_or - cppreference.com (original) (raw)

member only of atomic<_Integral_ > specializations
T fetch_or( T arg, std::memory_order order = std::memory_order_seq_cst ) noexcept; (1) (since C++11)
T fetch_or( T arg, std::memory_order order = std::memory_order_seq_cst ) volatile noexcept; (2) (since C++11)

Atomically replaces the current value with the result of bitwise OR of the value and arg. The operation is read-modify-write operation. Memory is affected according to the value of order.

It is deprecated if std::atomic<T>::is_always_lock_free is false and overload (2) participates in overload resolution. (since C++20)

[edit] Parameters

arg - the other argument of bitwise OR
order - memory order constraints to enforce

[edit] Return value

The value immediately preceding the effects of this function in the modification order of *this.

[edit] See also