std:: atomic_flag_test, std:: atomic_flag_test_explicit

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atomic_flag_test atomic_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 , 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 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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