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_store atomic_store_explicit (C++11) (C++11)

atomic_load atomic_load_explicit (C++11) (C++11)

atomic_exchange atomic_exchange_explicit (C++11) (C++11)

atomic_compare_exchange_weak atomic_compare_exchange_weak_explicit atomic_compare_exchange_strong atomic_compare_exchange_strong_explicit (C++11) (C++11) (C++11) (C++11)

atomic_fetch_add atomic_fetch_add_explicit (C++11) (C++11)

atomic_fetch_sub atomic_fetch_sub_explicit (C++11) (C++11)

atomic_fetch_and atomic_fetch_and_explicit (C++11) (C++11)

atomic_fetch_or atomic_fetch_or_explicit (C++11) (C++11)

atomic_fetch_xor atomic_fetch_xor_explicit (C++11) (C++11)

Atomic flags

atomic_flag (C++11)

atomic_flag_test_and_set atomic_flag_test_and_set_explicit (C++11) (C++11)

atomic_flag_clear atomic_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^=

 

T operator+=( T arg ); T operator+=( T arg ) volatile;	(1)	(member only of atomic<Integral> template specialization) (since C++11)
T* operator+=( std::ptrdiff_t arg ); T* operator+=( std::ptrdiff_t arg ) volatile;	(1)	(member only of atomic<T*> template specialization) (since C++11)
T operator-=( T arg ); T operator-=( T arg ) volatile;	(2)	(member only of atomic<Integral> template specialization) (since C++11)
T* operator-=( std::ptrdiff_t arg ); T* operator-=( std::ptrdiff_t arg ) volatile;	(2)	(member only of atomic<T*> template specialization) (since C++11)
T operator&=( T arg ); T operator&=( T arg ) volatile;	(3)	(member only of atomic<Integral> template specialization) (since C++11)
T operator|=( T arg ); T operator|=( T arg ) volatile;	(4)	(member only of atomic<Integral> template specialization) (since C++11)
T operator^=( T arg ); T operator^=( T arg ) volatile;	(5)	(member only of atomic<Integral> template specialization) (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.

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

  (since C++11)

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)