async-dup/README.md

# async-dup

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Duplicate an async I/O handle.

This crate provides two tools, `Arc` and `Mutex`:

* `Arc` implements `AsyncRead`, `AsyncWrite`, and `AsyncSeek` if a reference to the inner type does.
* A reference to `Mutex` implements `AsyncRead`, `AsyncWrite`, and `AsyncSeek` if the inner type does.

Wrap an async I/O handle in `Arc` or `Mutex` to clone it or share among tasks.

## Examples

Clone an async I/O handle:

```rust
use async_dup::Arc;
use futures::io;
use smol::Async;
use std::net::TcpStream;

// A client that echoes messages back to the server.
let stream = Async::<TcpStream>::connect("127.0.0.1:8000").await?;

// Create two handles to the stream.
let reader = Arc::new(stream);
let mut writer = reader.clone();

// Echo data received from the reader back into the writer.
io::copy(reader, &mut writer).await?;
```

Share an async I/O handle:

```rust
use async_dup::Mutex;
use futures::io;
use futures::prelude::*;

// Reads data from a stream and echoes it back.
async fn echo(stream: impl AsyncRead + AsyncWrite + Unpin) -> io::Result<u64> {
    let stream = Mutex::new(stream);
    io::copy(&stream, &mut &stream).await
}
```

## License

Licensed under either of

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