How can I support an unknown or other value for a Serde enum?

Question

I have a JSON API that returns an object that looks like this:

{
  \"PrivatePort\": 2222,
  \"PublicPort\": 3333,
  \"Type\": \"tcp\"
}

To

Answer 1

There's an issue for this, though it's been open for 3 years with no full resolution so far. Serde #912.

What seems to be currently implemented (though undocumented) at the time of this post is #[serde(other)]. It can only be applied to unit enum fields, which limits its usefulness:

#[derive(Deserialize, PartialEq)]
#[serde(tag = "tag")]
enum Target {
   A(()),
   B(()),
   #[serde(other)]
   Others
}

fn main() {
    assert_eq!(Target::Others, from_str::(r#"{ "tag": "blablah" }"#).unwrap());
}

Other than that, the only other method as of this writing is writing your own Deserialize implementation.