rust

use once_cell::sync::Lazy;
use regex::Regex;
use std::str::FromStr;

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord)]
pub enum Severity {

#[derive(Debug, Clone, PartialEq, Eq)]
pub struct EmailAddress(String);

impl EmailAddress {
    pub fn parse(raw: &str) -> Result<Self, String> {
        if raw.contains('@') && !raw.starts_with('@') {

#[derive(Debug, Clone)]
pub enum Outcome {
    Approve,
    Review,
    Reject(String),
}

use std::mem;

fn main() {
    let mut x = 5;
    let mut y = 10;

use std::error::Error;
use std::fmt;
use std::io;
use std::num::ParseIntError;

#[derive(Debug)]

use std::rc::Rc;
use std::cell::RefCell;

fn main() {
    let data = Rc::new(RefCell::new(vec![1, 2, 3]));

struct Logger {
    name: String,
}

impl Drop for Logger {
    fn drop(&mut self) {

use dashmap::DashMap;
use std::time::Instant;

pub struct TokenBucket {
    tokens: f64,
    last_refill: Instant,

struct Locked;
struct Unlocked;

struct Door<State> {
    _state: std::marker::PhantomData<State>,
}

use serde::{Deserialize, Serialize};

#[derive(Debug, Deserialize)]
pub struct SignupRequest {
    pub email: String,
    pub password: String,

use tokio::sync::broadcast;

pub struct Shutdown {
    is_shutdown: bool,
    notify: broadcast::Receiver<()>,
}

use tokio::time::{sleep, Duration};

async fn fetch_data() -> String {
    sleep(Duration::from_millis(100)).await;
    "data".to_string()
}