std::atomic::operator+=,-=,&=,|=,^=

 

C++

Language

Standard library headers

Concepts

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

 

Atomic operations library

Types

atomic (C++11)

atomic_is_lock_free (C++11)

Functions

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 flags

atomic_flag (C++11)

atomic_flag_test_and_setatomic_flag_test_and_set_explicit (C++11)(C++11)

atomic_flag_clearatomic_flag_clear_explicit (C++11)(C++11)

Initialization

atomic_init (C++11)

ATOMIC_VAR_INIT (C++11)

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)

 

std::atomic

Member functions

atomic::atomic

atomic::operator=

atomic::is_lock_free

atomic::store

atomic::load

atomic::operator T

atomic::exchange

atomic::compare_exchange

Specialized member functions

atomic::fetch_add

atomic::fetch_sub

atomic::fetch_and

atomic::fetch_or

atomic::fetch_xor

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

atomic::operator+=atomic::operator-=atomic::operator&=atomic::operator|=atomic::operator^=

 

(1)

(since C++11) (member only of atomic<Integral> template specialization)

T operator+=( T arg );

T operator+=( T arg ) volatile;

(1)

(since C++11) (member only of atomic<T*> template specialization)

T* operator+=( std::ptrdiff_t arg );

T* operator+=( std::ptrdiff_t arg ) volatile;

(2)

(since C++11) (member only of atomic<Integral> template specialization)

T operator-=( T arg );

T operator-=( T arg ) volatile;

(2)

(since C++11) (member only of atomic<T*> template specialization)

T* operator-=( std::ptrdiff_t arg );

T* operator-=( std::ptrdiff_t arg ) volatile;

(3)

(since C++11) (member only of atomic<Integral> template specialization)

T operator&=( T arg );

T operator&=( T arg ) volatile;

(4)

(since C++11) (member only of atomic<Integral> template specialization)

T operator|=( T arg );

T operator|=( T arg ) volatile;

(5)

(since C++11) (member only of atomic<Integral> template specialization)

T operator^=( T arg );

T operator^=( T arg ) volatile;

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

1) Performs atomic addition. Equivalent to fetch_add(arg) + arg.

2) Performs atomic subtraction. Equivalent to fetch_sub(arg) - arg.

3) Performs atomic bitwise and. Equivalent to fetch_and(arg) & arg.

4) Performs atomic bitwise or. Equivalent to fetch_or(arg) | arg.

5) Performs atomic bitwise exclusive or. Equivalent to fetch_xor(arg) ^ arg.

For signed Integral types, arithmetic is defined to use two’s complement representation. There are no undefined results. For T* types, the result may be an undefined address, but the operations otherwise have no undefined behavior.

Parameters

arg

-

the argument for the arithmetic operation

Return value

The resulting value.

Exceptions

noexcept specification:  

noexcept

  

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

operator++operator++(int)operator--operator--(int)	increments or decrements the atomic value by one (public member function)