NAME¶

std::atomic_flag_test,std::atomic_flag_test_explicit - std::atomic_flag_test,std::atomic_flag_test_explicit

Synopsis¶

Defined in header <atomic>
bool atomic_flag_test( const volatile std::atomic_flag* object ) (1) (since C++20)
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, (3) (since C++20)
std::memory_order order )
noexcept;
bool atomic_flag_test_explicit( const std::atomic_flag* object,
std::memory_order order ) (4) (since C++20)
noexcept;

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¶

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

Category:¶

* Todo no example