Public name for the layer-identifiability predicate — see _canFilterById.
The kernel calls it once per whole-collection write, caches the answer on the layer
entry, and reads that cache on every unit mutation. That placement is the whole
economy of the diff path: the predicate is O(N), so paying it per mutation would
cost exactly what the diff was introduced to save.
Public name for the layer-identifiability predicate — see
_canFilterById.The kernel calls it once per whole-collection write, caches the answer on the layer entry, and reads that cache on every unit mutation. That placement is the whole economy of the diff path: the predicate is O(N), so paying it per mutation would cost exactly what the diff was introduced to save.