atomic_flag_clear, atomic_flag_clear_explicit
From cppreference.com
                    
                                        
                    
                    
                                                            
                    |   Defined in header <stdatomic.h>
   | 
||
|   void atomic_flag_clear( volatile atomic_flag* obj );  | 
(1) | (since C11) | 
|   void atomic_flag_clear_explicit( volatile atomic_flag* obj, memory_order order );  | 
(2) | (since C11) | 
Atomically changes the state of a atomic_flag pointed to by obj to clear (false). The first version orders memory accesses according to memory_order_seq_cst, the second version orders memory accesses according to order.
[edit] Parameters
| obj | - | pointer to the atomic flag object to modify | 
| order | - | the memory synchronization ordering for this operation: all values are permitted | 
[edit] Return value
(none)
[edit] See also
|    sets an atomic_flag to true and returns the old value   (function)  | |
|   C++ documentation for atomic_flag_clear, atomic_flag_clear_explicit 
 | |