std::atomic_flag_test, std::atomic_flag_test_explicit - cppreference.com

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Defined in header

<atomic>

boolatomic_flag_test(constvolatilestd::atomic_flag*object)noexcept; (1) (since C++20)boolatomic_flag_test(conststd::atomic_flag*object)noexcept; (2) (since C++20)boolatomic_flag_test_explicit(constvolatilestd::atomic_flag*object,std::memory_orderorder)noexcept; (3) (since C++20)boolatomic_flag_test_explicit(conststd::atomic_flag*object,std::memory_orderorder)noexcept; (4) (since C++20)Atomically reads the value of the *object and returns the value.

1,2) The memory synchronization order is std::memory_order_seq_cst.

3,4) The memory synchronization order is order.

If order is one of std::memory_order::release and std::memory_order::acq_rel, the behavior is undefined.

Parameters

object - pointer to the atomic_flag object to read order - the memory synchronization ordering Return value

The value atomically read.

Notes

Feature-test

macroValueStdFeature

__cpp_lib_atomic_flag_test

201907L

(C++20)std::atomic_flag::testExample

See also

(C++20)

atomically returns the value of the flag
(public member function of std::atomic_flag)

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