fn main() {
    let f = file::create("E:\\foot.txt").await?;
    f.write_all(b"hello world").await?;
    let f = file::open("E:\\foot.txt").await?;
    let mut buffer = Vec::new();
    f.read_to_end(&mut buffer).await?;
}

use futures;
use tokio::runtime::Runtime;
use std::io::Result;
async fn func1() -> Result<()> {
    tokio::time::delay_for(tokio::time::Duration::from_secs(1)).await;
    println!("func1 finished!");
	Ok(())
}
async fn func2() -> Result<()> {
    println!("func2 finished!");
	Ok(())
}
async fn async_main() {
    let f1 = func1();
    let f2 = func2();

    if let Err(_) = futures::try_join!(f1, f2) {
		println!("Err!");
	}
}
fn main() {
    let mut runtime = Runtime::new().unwrap();
    runtime.block_on(async_main());
    println!("Hello, world!");
}

use futures::{select, future::FutureExt, pin_mut};
use tokio::runtime::Runtime;
use std::io::Result;
async fn func1() -> Result<()> {
	tokio::time::delay_for(tokio::time::Duration::from_secs(2)).await;
	println!("func1 finished!");
	Ok(())
}
async fn func2() -> Result<()> {
	println!("func2 finished!");
	Ok(())
}
async fn async_main() {
	let f1 = func1().fuse();
	let f2 = func2().fuse();
	pin_mut!(f1, f2);
	// 使用select 進(jìn)行匹配
	select! {
		_ = f1 => println!("func1 finished++++++!"),
		_ = f2 => println!("func2 finished++++++!"),
	}
}
fn main() {
// 使用tokio的runtime()
	let mut runtime = Runtime::new().unwrap();
	runtime.block_on(async_main());
    println!("Hello, world!");
}

use futures::{future, select, executor};
async fn count() {
	let mut a_fut = future::ready(4);
	let mut b_fut = future::ready(6);
	let mut total = 0;	
	loop {
		select! {
			a = a_fut => total += a,
			b = b_fut => total += b,
			complete => break,   //表示所有的分支都已經(jīng)完成，并且不會再取得進(jìn)展的情況
			default => unreachable!(), //表示沒有分支完成
		}
	}
	assert_eq!(total, 10);
}
fn main() {
	executor::block_on(count());
    println!("Hello, world!");
}

use std::rc::Rc;
#[derive(Default)]
struct NoSend(Rc<()>);
async fn bar() {}
async fn foo() {
	NoSend::default();
	//{
	//	let x = NoSend::default();
	//	//to do : xxxxx
	//}
	let _ = NoSend::default();
	bar().await;
}
//Send trait：如果所有的子類型都是實(shí)現(xiàn)Send trait的，那么它本身也是實(shí)現(xiàn)Send Trait的
// 如果內(nèi)部沒有定義 只是使用 是一個Send Trait 主要是在 生成 匿名結(jié)構(gòu)體中 會進(jìn)行解析
not let x: impl Send Trait
//struct Foo {
//	f: Future,
//}
let x: Not impl Send Trait
//struct Foo {
//	x: NoSend, //not impl Send Trait
//	f: Future, //impl Send Trait
//}
fn required_send(_: impl Send) {}
fn main() {
	required_send(foo());
    println!("Hello, world!");
}