[IshKebab]

They do because the standard library implementation was changed to use Hashbrown. However the standard library API has a slight limitation in that you can't get say "I have a reference to a string. If there's an entry for it, give me that. Otherwise clone the string and insert a new entry. Also only do one key lookup."

You end up either having to do two lookups or always cloning the string even if you ended up not needing it.

[GrumpySloth]

You can.

https://doc.rust-lang.org/std/collections/hash_map/enum.Entr...

[IshKebab]

You can't. `entry()` takes they key by value, not by reference:

https://doc.rust-lang.org/std/collections/hash_map/struct.Ha...

You might be getting confused because in that example the `HashMap` keys are references.

[GrumpySloth]

My bad. That’s not been an issue in my code, as I use arenas to manage memory and never put an owning container as key in a HashMap.