serializing json with non-string keys in a map

json_serde.md

You're trying to serde_json::to_string some struct that has an Hashmap that has non-string keys? (like a struct)

You're getting some Error("key must be a string", line: 0, column: 0) error?

You're not finding much help online?

Don't worry.

Simply use https://docs.rs/serde_with/1.5.0/serde_with/derive.SerializeDisplay.html on the type that you use as key