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

C++

Language

Headers

Freestanding and hosted implementations

Named requirements

Language support library

Concepts library (C++20)

Diagnostics library

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)

Filesystem library (C++17)

Technical Specifications

Atomic operations library

Types

atomic (C++11)

atomic_ref (C++20)

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_is_lock_free (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_ref

Member functions

atomic_ref::atomic_ref

atomic_ref::operator=

atomic_ref::is_lock_free

atomic_ref::store

atomic_ref::load

atomic_ref::operator T

atomic_ref::exchange

atomic_ref::compare_exchange_strongatomic_ref::compare_exchange_weak

Constants

atomic_ref::is_always_lock_free

atomic_ref::required_alignment

Specialized member functions

atomic_ref::fetch_add

atomic_ref::fetch_sub

atomic_ref::fetch_and

atomic_ref::fetch_or

atomic_ref::fetch_xor

atomic_ref::operator++atomic_ref::operator++(int)atomic_ref::operator--atomic_ref::operator--(int)

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

member only of atomic_ref<Integral> and atomic_ref<Floating> template specializations
T operator+=( T arg ) const noexcept;	(1)
member only of atomic_ref<T*> template specialization
T* operator+=( std::ptrdiff_t arg ) const noexcept;	(1)
member only of atomic_ref<Integral> and atomic_ref<Floating> template specializations
T operator-=( T arg ) const noexcept;	(1)
member only of atomic_ref<T*> template specialization
T* operator-=( std::ptrdiff_t arg ) const noexcept;	(1)
member only of atomic_ref<Integral> template specialization
T operator&=( T arg ) const noexcept;	(3)
T operator|=( T arg ) const noexcept;	(4)
T operator^=( T arg ) const noexcept;	(5)

Atomically replaces the current value of the referenced object with the result of computation involving the previous value and arg. These operations are read-modify-write operations.

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

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

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

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

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

For signed integral types, arithmetic is defined to use twos complement representation. There are no undefined results.

For floating-point types, the floating-point environment in effect may be different from the calling thread's floating-point environment. The operation need not be conform to the corresponding std::numeric_limits traits but is encouraged to do so. If the result is not a representable value for its type, the result is unspecified but the operation otherwise has no undefined behavior.

For T* types, the result may be an undefined address, but the operations otherwise have no undefined behavior. The program is ill-formed if T is not an object type.

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).

Notes

Unlike most compound assignment operators, the compound assignment operators for atomic_ref 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)

atomically increments or decrements the referenced object by one (public member function)