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std::atomic_init

From cppreference.com
< cpp‎ | atomic
 
 
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Atomic types
(C++11)
(C++20)
Initialization of atomic types
atomic_init
(C++11)(deprecated in C++20)
(C++11)(deprecated in C++20)
Memory ordering
Free functions for atomic operations
Free functions for atomic flags
 
Defined in header <atomic>
template< class T >

void atomic_init
    ( std::atomic<T>* obj,

      typename std::atomic<T>::value_type desired ) noexcept;
(1) (since C++11)
(deprecated in C++20)
template< class T >

void atomic_init
    ( volatile std::atomic<T>* obj,

      typename std::atomic<T>::value_type desired ) noexcept;
(2) (since C++11)
(deprecated in C++20)

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

Contents

[edit] Parameters

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

[edit] Return value

(none)

[edit] 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.

[edit] Example

[edit] 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 was required because
T was deduced from multiple arguments
T is only deduced
from obj

[edit] See also

(C++11)(deprecated in C++20)
constant initialization of an atomic variable of static storage duration
(function macro) [edit]
constructs an atomic object
(public member function of std::atomic<T>) [edit]
C documentation for atomic_init