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.


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

See also

checks if the atomic object is lock-free
(public member function)
checks if the atomic type's operations are lock-free
(function template)

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