It sounds like you'd want the entry API: https://doc.rust-lang.org/std/collections/struct.HashMap.html#method.entry https://doc.rust-lang.org/std/collections/st

It sounds like you'd want the entry API: https://doc.rust-lang.org/std/collections/struct.HashMap.html#method.entry https://doc.rust-lang.org/std/collections/struct.HashMap.htm...