Function from_str_auto 

pub fn from_str_auto<'a, T>(s: &'a str) -> DeResult<T>
where
    T: Deserialize<'a>,

The same as from_str but deserialize_any will deserialize byte string as str if input bytes are valid UTF-8, otherwise as bytes

Note

Thus making impossible to deserialize advanced Serde constructs like tagged enums with some penalty for simpler use cases.