#![allow(unused)]
fn main() {
use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};

let localhost_v4 = IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1));
let localhost_v6 = IpAddr::V6(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 1));

assert_eq!("127.0.0.1".parse(), Ok(localhost_v4));
assert_eq!("::1".parse(), Ok(localhost_v6));

assert_eq!(localhost_v4.is_ipv6(), false);
assert_eq!(localhost_v4.is_ipv4(), true);
}