std::atomic::fetch_add

 

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 fetch_add( T arg,              memory_order = std::memory_order_seq_cst ); T fetch_add( T arg,              memory_order = std::memory_order_seq_cst ) volatile;		(member only of atomic<Integral> template specialization) (since C++11)
T* fetch_add( std::ptrdiff_t arg,               memory_order = std::memory_order_seq_cst ); T* fetch_add( std::ptrdiff_t arg,               memory_order = std::memory_order_seq_cst ) volatile;		(member only of atomic<T*> template specialization) (since C++11)

Atomically replaces the current value with the result of arithmetic addition of the value and arg. The operation is read-modify-write operation. Memory is affected according to the value of memory_order.

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 other argument of arithmetic addition
memory_order	-	memory order constraints to enforce

Return value

The value of the atomic variable before the call.

Exceptions

noexcept specification:  

noexcept

  (since C++11)

See also

atomic_fetch_add atomic_fetch_add_explicit (C++11) (C++11)	adds a non-atomic value to an atomic object and obtains the previous value of the atomic (function template)