Comment by hazz

Yes, Ruby also has the same self-imposed constraint on insertion order. I agree it makes it more complicated to change the hash table implementation but it seems it wouldn’t be impossible to adapt Swiss Tables to support this. For example, by storing the “insertion number” (an incrementing integer) in each bucket, and possibly using table groups (as Go does) so that you only need to sort the buckets in a group, not the whole table, in order to yield entries in order. But this is just a naive sketch and I am not an expert on hash tables!