Method from_str

ch_03/src/main.rs:40–45

(id: &str)

    type Err = std::io::Error;

    fn from_str(id: &str) -> Result<Self, Self::Err> {
        match id.is_empty() {
            false => Ok(QuestionId(id.to_string())),
            true => Err(Error::new(ErrorKind::InvalidInput, "No id provided")),
        }
    }
}