std::atomic_flag_clear, std::atomic_flag_clear_explicit - cppreference.com (original) (raw)

Defined in header
void atomic_flag_clear( volatile std::atomic_flag* obj ) noexcept; (1) (since C++11)
void atomic_flag_clear( std::atomic_flag* obj ) noexcept; (2) (since C++11)
void atomic_flag_clear_explicit( volatile std::atomic_flag* obj, std::memory_order order ) noexcept; (3) (since C++11)
void atomic_flag_clear_explicit( std::atomic_flag* obj, std::memory_order order ) noexcept; (4) (since C++11)

Atomically changes the state of the std::atomic_flag pointed to by obj to clear (false).

3,4) The memory synchronization ordering is order.

[edit] Parameters

obj - pointer to std::atomic_flag to access
order - the memory synchronization ordering

[edit] Notes

std::atomic_flag_clear and std::atomic_flag_clear_explicit can be implemented as obj->clear() and obj->clear(order) respectively.

[edit] Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR Applied to Behavior as published Correct behavior
LWG 2138 C++11 order could be std::memory_order_consume the behavior is undefined in this case

[edit] See also