Function msgfmt 

pub fn msgfmt(m: &Message) -> String

An utility function for translation by using the optional text attribute.

Example

    let msg = Message {
      id: "lorem.ipsum",
      text: Some("Lorem {0} dolor {1} amet"),
      args: vec!["ipsum".to_string(), "sit".to_string()],
    };
    let out = msgfmt(&msg);
    assert_eq!("Lorem ipsum dolor sit amet", out);

    // it's used also for fmt::Display::fmt()
    assert_eq!(msg.to_string(), out);