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

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< cpp‎ | atomic‎ | atomic
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(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.

Contents

[edit] Parameters

arg - the argument for the arithmetic operation

[edit] Return value

The resulting value.

[edit] Exceptions

noexcept specification:  
noexcept
  

[edit] 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.

[edit] See also

increments or decrements the atomic value by one
(public member function) [edit]