gistfile1.txt

typedef NS_OPTIONS(NSUInteger, ASDisplayNodeMethodOverrides)
{
  ASDNFlagSynchronous = 0,
  ASDNFlagLayerBacked = 1 << 0,
};

#define isSynchronous _atomicFlags.fetch_or(ASDNFlagSynchronous)
#define isLayerBacked _atomicFlags.fetch_or(ASDNFlagLayerBacked)

@interface ASDisplayNode ()
{
@package
  _ASPendingState *_pendingViewState;

  UIView *_view;
  CALayer *_layer;

  std::atomic<uint_least32_t> _atomicFlags;
...
}