Async version of the Rust standard library

This crate provides an async version of std. It provides all the interfaces you are used to, but in an async version and ready for Rust's async/await syntax.

Documentation

async-std comes with extensive API documentation and a book.

Quickstart

Add the following lines to your Cargo.toml:

[dependencies]
async-std = "0.99"

Or use cargo add if you have it installed:

$ cargo add async-std

Hello world

use async_std::task;

fn main() {
    task::block_on(async {
        println!("Hello, world!");
    })
}

Low-Friction Sockets with Built-In Timeouts

use std::time::Duration;

use async_std::{
    prelude::*,
    task,
    io,
    net::TcpStream,
};

async fn get() -> io::Result<Vec<u8>> {
    let mut stream = TcpStream::connect("example.com:80").await?;
    stream.write_all(b"GET /index.html HTTP/1.0\r\n\r\n").await?;

    let mut buf = vec![];

    io::timeout(Duration::from_secs(5), async {
        stream.read_to_end(&mut buf).await?;
        Ok(buf)
    }).await
}

fn main() {
    task::block_on(async {
        let raw_response = get().await.expect("request");
        let response = String::from_utf8(raw_response)
            .expect("utf8 conversion");
        println!("received: {}", response);
    });
}

Features

async-std is strongly commited to following semver. This means your code won't break unless you decide to upgrade.

However every now and then we come up with something that we think will work great for async-std, and we want to provide a sneak-peek so you can try it out. This is what we call "unstable" features. You can try out the unstable features by enabling the unstable feature in your Cargo.toml file:

[dependencies.async-std]
version = "0.99"
features = ["unstable"]

Just be careful when using these features, as they may change between versions.

Take a look around

Clone the repo:

git clone git@github.com:async-rs/async-std.git && cd async-std

Generate docs:

cargo +nightly doc --features docs --open

Check out the examples. To run an example:

cargo +nightly run --example hello-world

Contributing

See our contribution document.

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.