#[macro_use]                         
extern crate serde_derive;

use serde;
use serde_json;
use serde::{Serialize, Deserialize};

#[derive(Debug, Serialize, Deserialize)]
#[serde(untagged)]
enum Data {
    Integer(u64),
    Pair(String, String),
}

fn main() {
    let w = Data::Integer(1);
    let w_str = serde_json::to_string(&w).unwrap();
    println!("{:?}", w_str);
    let w_deser = serde_json::from_str::<Data>(&w_str).unwrap();
    println!("{:?}", w_deser);
}