atomic_flag_test_and_set, atomic_flag_test_and_set_explicit
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                    |   Defined in header  
<stdatomic.h>
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|   _Bool atomic_flag_test_and_set( volatile atomic_flag* obj ); 
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(1) | (since C11) | 
|   _Bool atomic_flag_test_and_set_explicit( volatile atomic_flag* obj, memory_order order ); 
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(2) | (since C11) | 
Atomically changes the state of a atomic_flag pointed to by obj to set (true) and returns the previous value. 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
The previous value held by the atomic flag pointed to by obj.
[edit] See also
|    sets an atomic_flag to false   (function)  | 
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C++ documentation for atomic_flag_test_and_set, atomic_flag_test_and_set_explicit
 
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