std::atomic_flag_test, std::atomic_flag_test_explicit

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

Parameters

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

Return value

The value atomically read.

Notes

Feature-test macro Value Std Feature
__cpp_lib_atomic_flag_test 201907L (C++20) std::atomic_flag::test

Example

This section is incomplete
Reason: no example

See also

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