W3cubDocs

/C++

std::atomic_flag_test, std::atomic_flag_test_explicit

Defined in header <atomic>
(1) (since C++20) 
bool atomic_flag_test( const volatile std::atomic_flag* object ) noexcept;
 
bool atomic_flag_test( const std::atomic_flag* object ) noexcept;
(2) (since C++20) 
bool atomic_flag_test_explicit( const volatile std::atomic_flag* object, 
                                std::memory_order order ) noexcept;
 
bool atomic_flag_test_explicit( const std::atomic_flag* object, 
                                std::memory_order order ) noexcept;

Atomically reads the value of the *object and returns the value.

1) Equivalent to object->test(std::memory_order_seq_cst).
2) Equivalent to object->test(order).

Parameters

object - pointer to the atomic_flag object to read
order - the memory synchronization ordering for this operation: must not be std::memory_order::release or std::memory_order::acq_rel

Return value

The value atomically read.

Notes

Feature-test macro
__cpp_lib_atomic_flag_test

Example

See also

(C++20)
 atomically returns the value of the flag
(public member function of std::atomic_flag)

© cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
https://en.cppreference.com/w/cpp/atomic/atomic_flag_test