std::atomic_init

Defined in header <atomic>

Defined in header `<atomic>`
template< class T > void atomic_init( std::atomic<T>* obj, typename std::atomic<T>::value_type desired ) noexcept;		(since C++11)
template< class T > void atomic_init( volatile std::atomic<T>* obj, typename std::atomic<T>::value_type desired ) noexcept;		(since C++11)

template< class T >
void atomic_init( std::atomic<T>* obj,
                  typename std::atomic<T>::value_type desired ) noexcept;

(since C++11)

template< class T >
void atomic_init( volatile std::atomic<T>* obj,
                  typename std::atomic<T>::value_type desired ) noexcept;

(since C++11)

Initializes the default-constructed atomic object obj with the value desired. The function is not atomic: concurrent access from another thread, even through an atomic operation, is a data race.

If obj was not default-constructed, the behavior is undefined.

If this function is called twice on the same obj, the behavior is undefined.

Parameters

obj	-	pointer to an atomic object to initialize
desired	-	the value to initialize atomic object with

Return value

(none).

Notes

This function is provided for compatibility with C. If the compatibility is not required, std::atomic may be initialized through their non-default constructors.

Example

Defect reports

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 required because `T` is deduced from multiple arguments	`T` is deduced from the `atomic` argument only

ATOMIC_VAR_INIT (C++11)	constant initialization of an atomic variable of static storage duration (function macro)
(constructor)	constructs an atomic object (public member function of `std::atomic<T>`)