Specifies whether, in a garbage collected environment, pointers should use weak read and write barriers.
- iOS 2.0–10.0Deprecated
- macOS 10.5–10.12Deprecated
- Mac Catalyst 13.0–13.0Deprecated
- tvOS 9.0–10.0Deprecated
- watchOS 2.0–3.0Deprecated
If you use garbage collection, read and write barrier functions must be used when pointers are from memory scanned by the collector.