< c‎ | atomic
Defined in header <stdatomic.h>
#define ATOMIC_FLAG_INIT /* unspecified */
(since C11)

Expands to an expression that can be used to initialize atomic_flag type. The value atomic_flag that is not initialized using this macro is undefined.


#include <stdatomic.h>
atomic_flag flag = ATOMIC_FLAG_INIT;


  • C11 standard (ISO/IEC 9899:2011):
  • 7.17.1/3 ATOMIC_FLAG_INIT (p: 273)
  • 7.17.8/4 ATOMIC_FLAG_INIT (p: 285)

See also

(C11)(deprecated in C17)
initializes a new atomic object
(function macro)
lock-free atomic boolean flag