std::atomic_flag::clear
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std::atomic_flag 
 
 
 
 
 
 Member functions
atomic_flag::clear
(C++20)
(C++20)
(C++20)
(C++20)
Defined in header 
 
 
<atomic> 
 void clear( std::memory_order order =
std::memory_order_seq_cst ) volatile noexcept;
 (1) 
 (since C++11) 
std::memory_order_seq_cst ) volatile noexcept;
void clear( std::memory_order order =
std::memory_order_seq_cst ) noexcept;
 (2) 
 (since C++11) 
std::memory_order_seq_cst ) noexcept;
Atomically changes the state of a std::atomic_flag to clear (false).
If order is one of std::memory_order_consume , std::memory_order_acquire and std::memory_order_acq_rel , the behavior is undefined.
[edit] Parameters
 order
 -
 the memory synchronization ordering
[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 |