`String` successfully parses bytes buffer

[russellmcc]

I have a pre-existing msgpack schema that I tried to encode in rmp-serde like this:

#[derive(Serialize, Deserialize, PartialEq, Debug, Clone)]
#[serde(untagged)]
pub enum Value {
    Numeric(f32),
    String(String),
    #[serde(with = "serde_bytes")]
    Bytes(Vec<u8>),
    Bool(bool),
}

However, if I use rmp-serde to decode a buffer that happens to contain valid utf-8, like

{
    "m": "set",
    "path": "ui-state",
    "value": {
        "type": "Buffer",
        "data": [
            97
        ]
    }
}

(base64 g6Fto3NldKRwYXRoqHVpLXN0YXRlpXZhbHVlxAFh), I get a String, but I actually wanted a Bytes. It would be nice if there were some sort of strictness annotation that would make this behave as intended.

[russellmcc]

Also, if I reverse the order of the enum, Bytes will match actual strings, even though I only want it to match byte buffers