we only effectively need 1 control bit to represent 2 special states for
the metadata (free and tombstone)
this should reduce the number of actual element equality tests, but since
it's very low already, the impact is negligible
2d4d4baa42Sahnvour committed on 5/14/2021, 7:15:55 PM· committed by Andrew Kelleyparent8b4e91e