the map member used for the lookups is a tsl::hopscotch_map (https://github.com/Tessil/hopscotch-map https://github.com/Tessil/hopscotch-map), which is a proper

the map member used for the lookups is a tsl::hopscotch_map (https://github.com/Tessil/hopscotch-map https://github.com/Tessil/hopscotch-map), which is a proper hash map. so it seems to be the latter, that the API is wrong, but from what I can tell it is only a wrongly named class. i don't see where the API makes guarantees about iteration order, which is where the implementation difference would be noticeable (beyond performance for lookup).