rayon

# Rayon

[![Rayon crate](https://img.shields.io/crates/v/rayon.svg)](https://crates.io/crates/rayon)
[![Rayon documentation](https://docs.rs/rayon/badge.svg)](https://docs.rs/rayon)
![minimum rustc 1.85](https://img.shields.io/badge/rustc-1.85+-red.svg)
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Rayon is a data-parallelism library for Rust. It is extremely
lightweight and makes it easy to convert a sequential computation into
a parallel one. It also guarantees data-race freedom. (You may also
enjoy [this blog post][blog] about Rayon, which gives more background
and details about how it works, or [this video][video], from the Rust
Belt Rust conference.) Rayon is
[available on crates.io](https://crates.io/crates/rayon), and
[API documentation is available on docs.rs](https://docs.rs/rayon).

[blog]: https://smallcultfollowing.com/babysteps/blog/2015/12/18/rayon-data-parallelism-in-rust/
[video]: https://www.youtube.com/watch?v=gof_OEv71Aw

## Parallel iterators and more

Rayon makes it drop-dead simple to convert sequential iterators into
parallel ones: usually, you just change your `foo.iter()` call into
`foo.par_iter()`, and Rayon does the rest:

```rust
use rayon::prelude::*;
fn sum_of_squares(input: &[i32]) -> i32 {
    input.par_iter() // <-- just change that!
         .map(|&i| i * i)
         .sum()
}
```

[Parallel iterators] take care of deciding how to divide your data
into tasks; it will dynamically adapt for maximum performance. If you
need more flexibility than that, Rayon also offers the [join] and
[scope] functions, which let you create parallel tasks on your own.
For even more control, you can create [custom thread pools] rather than
using Rayon's default, global thread pool.

[Parallel iterators]: https://docs.rs/rayon/*/rayon/iter/index.html
[join]: https://docs.rs/rayon/*/rayon/fn.join.html
[scope]: https://docs.rs/rayon/*/rayon/fn.scope.html
[custom thread pools]: https://docs.rs/rayon/*/rayon/struct.ThreadPool.html

## No data races

You may have heard that parallel execution can produce all kinds of
crazy bugs. Well, rest easy. Rayon's APIs all guarantee **data-race
freedom**, which generally rules out most parallel bugs (though not
all). In other words, **if your code compiles**, it typically does the
same thing it did before.

For the most part, parallel iterators in particular are guaranteed to
produce the same results as their sequential counterparts. One caveat:
If your iterator has side effects (for example, sending methods to
other threads through a [Rust channel] or writing to disk), those side
effects may occur in a different order. Note also that, in some cases,
parallel iterators offer alternative versions of the sequential
iterator methods that can have higher performance.

[Rust channel]: https://doc.rust-lang.org/std/sync/mpsc/fn.channel.html

## Using Rayon

[Rayon is available on crates.io](https://crates.io/crates/rayon). The
recomm