use std::fmt;

#[derive(Debug)]
enum TagData {
    Int(i32),
    Float(f64),
    String(String),
    None,
}

impl fmt::Display for TagData {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match self {
            TagData::Int(i) => write!(f, "{}", i),
            TagData::Float(fl) => write!(f, "{}", fl),
            TagData::String(s) => write!(f, "{}", s),
            TagData::None => write!(f, "None")
        }
    }
}

fn main(){
    let d = TagData::Int(42);
    print!("{:?} vs {}", d, d);
}