Code shared from the Rust Playground

playground.rs

use std::net::{SocketAddr, UdpSocket};
use std::sync::{Arc, Mutex};
use serde::Serialize;
use serde_json::Value;

#[derive(Serialize)]
pub struct Peer {
    ip: SocketAddr,
}

pub fn foo(_socket: &UdpSocket, _packet: Value, target_addr: SocketAddr, peers: Arc<Mutex<Vec<Peer>>>) {
        let lock = peers.lock().expect("cannot lock the peers");
        if !lock.iter().find(|x| x.ip == target_addr).is_some() {
            let _packet = write_packet(&*lock);
        }
}

fn write_packet<T: Serialize>(_data: &T) -> String { serde_json::to_string(_data).unwrap() }