Annex D (normative) Compatibility features [depr]

D.22 Deprecated atomic operations [depr.atomics]

D.22.4 Operations on atomic types [depr.atomics.types.operations]

#define ATOMIC_VAR_INIT(value) see below
The macro expands to a token sequence suitable for constant initialization of an atomic variable of static storage duration of a type that is initialization-compatible with value.
[Note 1: 
This operation possibly needs to initialize locks.
— end note]
Concurrent access to the variable being initialized, even via an atomic operation, constitutes a data race.
[Example 1: atomic<int> v = ATOMIC_VAR_INIT(5); — end example]