std::atomic<T>::operator&=,|=,^=

 

C++

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Concurrency support library

Threads thread (C++11) jthread (C++20) hardware_destructive_interference_sizehardware_constructive_interference_size (C++17)(C++17) this_thread namespace get_id (C++11) yield (C++11) sleep_for (C++11) sleep_until (C++11) Cooperative cancellation stop_token (C++20) inplace_stop_token (C++26) never_stop_token (C++26) stop_source (C++20) inplace_stop_source (C++26)   stop_callback (C++20) inplace_stop_callback (C++26) stop_callback_for_t (C++26) stoppable_token (C++26) unstoppable_token (C++26) stoppable-source (C++26) stoppable-callback-for (C++26)   Mutual exclusion mutex (C++11) recursive_mutex (C++11) shared_mutex (C++17) timed_mutex (C++11) recursive_timed_mutex (C++11) shared_timed_mutex (C++14) Generic lock management lock (C++11) lock_guard (C++11) scoped_lock (C++17) unique_lock (C++11) shared_lock (C++14) once_flag (C++11) call_once (C++11) try_lock (C++11) defer_locktry_to_lockadopt_lockdefer_lock_ttry_to_lock_tadopt_lock_t (C++11)(C++11)(C++11)(C++11)(C++11)(C++11) Condition variables condition_variable (C++11) condition_variable_any (C++11) notify_all_at_thread_exit (C++11) cv_status (C++11) Semaphores counting_semaphorebinary_semaphore (C++20)(C++20) Latches and Barriers latch (C++20) barrier (C++20) Futures promise (C++11) future (C++11) shared_future (C++11) packaged_task (C++11) async (C++11) launch (C++11) future_status (C++11) future_error (C++11) future_category (C++11) future_errc (C++11) Safe Reclamation rcu_obj_base (C++26) rcu_domain (C++26) rcu_default_domain (C++26) rcu_synchronize (C++26) rcu_barrier (C++26) rcu_retire (C++26) Hazard Pointers hazard_pointer_obj_base (C++26) hazard_pointer (C++26) make_hazard_pointer (C++26)

Atomic types atomic (C++11) atomic_ref (C++20) atomic_flag (C++11) Initialization of atomic types atomic_init (C++11)(deprecated in C++20) ATOMIC_VAR_INIT (C++11)(deprecated in C++20) ATOMIC_FLAG_INIT (C++11) Memory ordering memory_order (C++11) kill_dependency (C++11) atomic_thread_fence (C++11) atomic_signal_fence (C++11) Free functions for atomic operations atomic_storeatomic_store_explicit (C++11)(C++11) atomic_loadatomic_load_explicit (C++11)(C++11) atomic_exchangeatomic_exchange_explicit (C++11)(C++11) atomic_compare_exchange_weakatomic_compare_exchange_weak_explicitatomic_compare_exchange_strongatomic_compare_exchange_strong_explicit (C++11)(C++11)(C++11)(C++11) atomic_fetch_addatomic_fetch_add_explicit (C++11)(C++11) atomic_fetch_subatomic_fetch_sub_explicit (C++11)(C++11) atomic_fetch_andatomic_fetch_and_explicit (C++11)(C++11) atomic_fetch_oratomic_fetch_or_explicit (C++11)(C++11) atomic_fetch_xoratomic_fetch_xor_explicit (C++11)(C++11) atomic_fetch_maxatomic_fetch_max_explicit (C++26)(C++26) atomic_fetch_minatomic_fetch_min_explicit (C++26)(C++26) atomic_is_lock_free (C++11) atomic_waitatomic_wait_explicit (C++20)(C++20) atomic_notify_one (C++20) atomic_notify_all (C++20) Free functions for atomic flags atomic_flag_test_and_setatomic_flag_test_and_set_explicit (C++11)(C++11) atomic_flag_clearatomic_flag_clear_explicit (C++11)(C++11) atomic_flag_testatomic_flag_test_explicit (C++20)(C++20) atomic_flag_waitatomic_flag_wait_explicit (C++20)(C++20) atomic_flag_notify_one (C++20) atomic_flag_notify_all (C++20)

 

std::atomic

Member functions

atomic::atomic

atomic::operator=

atomic::is_lock_free

atomic::store

atomic::load

atomic::operator T

atomic::exchange

atomic::compare_exchange_strongatomic::compare_exchange_weak

atomic::wait (C++20)

atomic::notify_one (C++20)

atomic::notify_all (C++20)

Constants

atomic::is_always_lock_free (C++17)

Specialized member functions

Specialized for integral, floating-point (C++20) and pointer types

atomic::fetch_add

atomic::fetch_sub

atomic::operator+=atomic::operator-=

Specialized for integral and pointer types only

atomic::fetch_max (C++26)

atomic::fetch_min (C++26)

atomic::operator++atomic::operator++(int)atomic::operator--atomic::operator--(int)

Specialized for integral types only

atomic::fetch_and

atomic::fetch_or

atomic::fetch_xor

atomic::operator&=atomic::operator|=atomic::operator^=

 

member only of atomic<Integral > specializations
T operator&=( T arg ) noexcept;	(1)	(since C++11)
T operator&=( T arg ) volatile noexcept;	(2)	(since C++11)
T operator|=( T arg ) noexcept;	(3)	(since C++11)
T operator|=( T arg ) volatile noexcept;	(4)	(since C++11)
T operator^=( T arg ) noexcept;	(5)	(since C++11)
T operator^=( T arg ) volatile noexcept;	(6)	(since C++11)

Atomically replaces the current value with the result of computation involving the previous value and arg. The operation is read-modify-write operation.

• operator&= performs atomic bitwise and. Equivalent to return fetch_and(arg) & arg;.
• operator|= performs atomic bitwise or. Equivalent to return fetch_or(arg) | arg;.
• operator^= performs atomic bitwise exclusive or. Equivalent to return fetch_xor(arg) ^ arg;.

It is deprecated if std::atomic<T>::is_always_lock_free is false and any volatile overload participates in overload resolution.

(since C++20)

Parameters

arg

-

the argument for the arithmetic operation

Return value

The resulting value (that is, the result of applying the corresponding binary operator to the value immediately preceding the effects of the corresponding member function in the modification order of *this).

Notes

Unlike most compound assignment operators, the compound assignment operators for atomic types do not return a reference to their left-hand arguments. They return a copy of the stored value instead.

See also

fetch_and	atomically performs bitwise AND between the argument and the value of the atomic object and obtains the value held previously (public member function)
fetch_or	atomically performs bitwise OR between the argument and the value of the atomic object and obtains the value held previously (public member function)
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)
operator++operator++(int)operator--operator--(int)	increments or decrements the atomic value by one (public member function)
operator+=operator-=	adds to or subtracts from the atomic value (public member function)