rust

struct Locked;
struct Unlocked;

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

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

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

// In a proc-macro crate:
use proc_macro::TokenStream;
use quote::quote;
use syn::{parse_macro_input, DeriveInput};

#[proc_macro_derive(MyTrait)]

#![feature(asm)]

fn add_asm(a: u64, b: u64) -> u64 {
    let result: u64;
    unsafe {
        asm!(

fn print_size<T: ?Sized>(value: &T) {
    // Can accept both &str and &String
    println!("Value: {:p}", value as *const T as *const ());
}

fn main() {

mod utils {
    pub fn helper() {
        println!("Helper function");
    }

    fn private_fn() {}