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std::atomic<T>::is_always_lock_free

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< cpp‎ | atomic‎ | atomic

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static constexpr bool is_always_lock_free = /*implementation-defined*/;

(since C++17)

Equals true if this atomic type is always lock-free and false if it is never or sometimes lock-free.

The value of this constant is consistent with both the macro ATOMIC_xxx_LOCK_FREE, where defined, with the member function is_lock_free and non-member function std::atomic_is_lock_free .

[edit] Notes

There is no non-member function equivalent of this static member constant because non-member functions take pointers to atomic types, and therefore aren't as useful in constant expressions.

Feature-test macro	Value	Std	Feature
`__cpp_lib_atomic_is_always_lock_free`	`201603L`	(C++17)	`constexpr atomic<T>::is_always_lock_free`

[edit] See also

checks if the atomic object is lock-free
(public member function) [edit]

atomic_is_lock_free

(C++11)

checks if the atomic type's operations are lock-free
(function template) [edit]

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