You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: udp-echo.rs
    path of file: ./repos/async-std/examples
    
    the code of the file until where you have to start completion: //! UDP echo server.
//!
//! To send messages, do:
//!
//! ```sh
//! $ nc -u localhost 8080
//! ```

use async_std::io;
use async_std::net::UdpSocket;
use async_std::task;

fn main() -> io::Result<()> {
    task::block_on(async {
        let socket = UdpSocket::bind("127.0.0.1:8080").await?;
     
    
fn main() -> io::Result<()> {
    task::block_on(async {
        let socket = UdpSocket::bind("127.0.0.1:8080").await?;
        let mut buf = vec![0u8; 1024];

        println!("Listening on {}", socket.local_addr()?);

        loop {
            let (n, peer) = socket.recv_from(&mut buf).await?;
            let sent = socket.send_to(&buf[..n], &peer).await?;
            println!("Sent {} out of {} bytes to {}", sent, n, peer);
        }
    })
}