std::atomic_store, std::atomic_store_explicit - cppreference.com

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Defined in header `<atomic>`
template< class T > void atomic_store( std::atomic<T>* obj, typename std::atomic<T>::value_type desired ) noexcept;	(1)	(since C++11)
template< class T > void atomic_store( volatile std::atomic<T>* obj, typename std::atomic<T>::value_type desired ) noexcept;	(2)	(since C++11)
template< class T > void atomic_store_explicit( std::atomic<T>* obj, typename std::atomic<T>::value_type desired, std::memory_order order) noexcept;	(3)	(since C++11)
template< class T > void atomic_store_explicit( volatile std::atomic<T>* obj, typename std::atomic<T>::value_type desired, std::memory_order order) noexcept;	(4)	(since C++11)

1,2) Atomically replaces the value pointed to by obj with the value of desired as if by obj->store(desired).

3,4) Atomically replaces the value pointed to by obj with the value of desired as if by obj->store(desired, order).

If order is one of std::memory_order_consume, std::memory_order_acquire and std::memory_order_acq_rel, the behavior is undefined.

obj	-	pointer to the atomic object to modify
desired	-	the value to store in the atomic object
order	-	the memory synchronization ordering

(none)

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR	Applied to	Behavior as published	Correct behavior
P0558R1	C++11	exact type match was required because `T` was deduced from multiple arguments	`T` is only deduced from `obj`

	atomically replaces the value of the atomic object with a non-atomic argument (public member function of `std::atomic<T>`) [edit]
	atomically obtains the value stored in an atomic object (function template) [edit]
	defines memory ordering constraints for the given atomic operation (enum) [edit]