futures-enum 0.1.18

#[derive(Future, Stream, Sink, AsyncRead, AsyncWrite, AsyncSeek, AsyncBufRead)] for enums.
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# futures-enum

[![crates.io](https://img.shields.io/crates/v/futures-enum?style=flat-square&logo=rust)](https://crates.io/crates/futures-enum)
[![docs.rs](https://img.shields.io/badge/docs.rs-futures--enum-blue?style=flat-square&logo=docs.rs)](https://docs.rs/futures-enum)
[![license](https://img.shields.io/badge/license-Apache--2.0_OR_MIT-blue?style=flat-square)](#license)
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\#\[derive(Future, Stream, Sink, AsyncRead, AsyncWrite, AsyncSeek, AsyncBufRead)\] for enums.

## Usage

Add this to your `Cargo.toml`:

```toml
[dependencies]
futures-enum = "0.1.16"
futures = "0.3"
```

## Examples

```rust
use std::future::Future;

use futures_enum::{Future, Stream, Sink, AsyncRead, AsyncWrite, AsyncSeek, AsyncBufRead};

#[derive(Future, Stream, Sink, AsyncRead, AsyncWrite, AsyncSeek, AsyncBufRead)]
enum Either<A, B> {
    A(A),
    B(B),
}

fn foo(x: i32) -> impl Future<Output = i32> {
    if x < 0 {
        Either::A(async { 1 })
    } else {
        Either::B(async move { x })
    }
}
```

futures-enum works well even if the dependency contains only sub-crates such
as `futures-core`, `futures-io`, `futures-sink`, etc.

See [auto_enums] crate for how to automate patterns like this.

## Supported traits

- [`Future`](https://doc.rust-lang.org/std/future/trait.Future.html) - [example](https://github.com/taiki-e/futures-enum/blob/HEAD/tests/expand/future.rs) | [generated code](https://github.com/taiki-e/futures-enum/blob/HEAD/tests/expand/future.expanded.rs)
- [`Stream`](https://docs.rs/futures/latest/futures/stream/trait.Stream.html) - [example](https://github.com/taiki-e/futures-enum/blob/HEAD/tests/expand/stream.rs) | [generated code](https://github.com/taiki-e/futures-enum/blob/HEAD/tests/expand/stream.expanded.rs)
- [`Sink`](https://docs.rs/futures/latest/futures/sink/trait.Sink.html) - [example](https://github.com/taiki-e/futures-enum/blob/HEAD/tests/expand/sink.rs) | [generated code](https://github.com/taiki-e/futures-enum/blob/HEAD/tests/expand/sink.expanded.rs)
- [`AsyncRead`](https://docs.rs/futures/latest/futures/io/trait.AsyncRead.html) - [example](https://github.com/taiki-e/futures-enum/blob/HEAD/tests/expand/async_read.rs) | [generated code](https://github.com/taiki-e/futures-enum/blob/HEAD/tests/expand/async_read.expanded.rs)
- [`AsyncWrite`](https://docs.rs/futures/latest/futures/io/trait.AsyncWrite.html) - [example](https://github.com/taiki-e/futures-enum/blob/HEAD/tests/expand/async_write.rs) | [generated code](https://github.com/taiki-e/futures-enum/blob/HEAD/tests/expand/async_write.expanded.rs)
- [`AsyncSeek`](https://docs.rs/futures/latest/futures/io/trait.AsyncSeek.html) - [example](https://github.com/taiki-e/futures-enum/blob/HEAD/tests/expand/async_seek.rs) | [generated code](https://github.com/taiki-e/futures-enum/blob/HEAD/tests/expand/async_seek.expanded.rs)
- [`AsyncBufRead`](https://docs.rs/futures/latest/futures/io/trait.AsyncBufRead.html) - [example](https://github.com/taiki-e/futures-enum/blob/HEAD/tests/expand/async_buf_read.rs) | [generated code](https://github.com/taiki-e/futures-enum/blob/HEAD/tests/expand/async_buf_read.expanded.rs)

## Related Projects

- [auto_enums]: A library for to allow multiple return types by automatically generated enum.
- [derive_utils]: A procedural macro helper for easily writing [derives macros][proc-macro-derive] for enums.
- [io-enum]: \#\[derive(Read, Write, Seek, BufRead)\] for enums.
- [iter-enum]: \#\[derive(Iterator, DoubleEndedIterator, ExactSizeIterator, Extend)\] for enums.

[auto_enums]: https://github.com/taiki-e/auto_enums
[derive_utils]: https://github.com/taiki-e/derive_utils
[io-enum]: https://github.com/taiki-e/io-enum
[iter-enum]: https://github.com/taiki-e/iter-enum
[proc-macro-derive]: https://doc.rust-lang.org/reference/procedural-macros.html#derive-macros

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## License

Licensed under either of [Apache License, Version 2.0](LICENSE-APACHE) or
[MIT license](LICENSE-MIT) at your option.

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.