Similar to base R's .Last.value, data.table could save .Last.updated holding the number of rows updated by the last :=. This could be used afterwards in production code to check that if row updates are expected then they occur and for reporting and logging.
Similar to base R's
.Last.value, data.table could save.Last.updatedholding the number of rows updated by the last:=. This could be used afterwards in production code to check that if row updates are expected then they occur and for reporting and logging.