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diff --git a/third_party/rust/fastrand/README.md b/third_party/rust/fastrand/README.md new file mode 100644 index 0000000000..0da0612ea4 --- /dev/null +++ b/third_party/rust/fastrand/README.md @@ -0,0 +1,92 @@ +# fastrand + +[![Build](https://github.com/smol-rs/fastrand/workflows/Build%20and%20test/badge.svg)]( +https://github.com/smol-rs/fastrand/actions) +[![License](https://img.shields.io/badge/license-Apache--2.0_OR_MIT-blue.svg)]( +https://github.com/smol-rs/fastrand) +[![Cargo](https://img.shields.io/crates/v/fastrand.svg)]( +https://crates.io/crates/fastrand) +[![Documentation](https://docs.rs/fastrand/badge.svg)]( +https://docs.rs/fastrand) + +A simple and fast random number generator. + +The implementation uses [Wyrand](https://github.com/wangyi-fudan/wyhash), a simple and fast +generator but **not** cryptographically secure. + +## Examples + +Flip a coin: + +```rust +if fastrand::bool() { + println!("heads"); +} else { + println!("tails"); +} +``` + +Generate a random `i32`: + +```rust +let num = fastrand::i32(..); +``` + +Choose a random element in an array: + +```rust +let v = vec![1, 2, 3, 4, 5]; +let i = fastrand::usize(..v.len()); +let elem = v[i]; +``` + +Shuffle an array: + +```rust +let mut v = vec![1, 2, 3, 4, 5]; +fastrand::shuffle(&mut v); +``` + +Generate a random `Vec` or `String`: + +```rust +use std::iter::repeat_with; + +let v: Vec<i32> = repeat_with(|| fastrand::i32(..)).take(10).collect(); +let s: String = repeat_with(fastrand::alphanumeric).take(10).collect(); +``` + +To get reproducible results on every run, initialize the generator with a seed: + +```rust +// Pick an arbitrary number as seed. +fastrand::seed(7); + +// Now this prints the same number on every run: +println!("{}", fastrand::u32(..)); +``` + +To be more efficient, create a new `Rng` instance instead of using the thread-local +generator: + +```rust +use std::iter::repeat_with; + +let rng = fastrand::Rng::new(); +let mut bytes: Vec<u8> = repeat_with(|| rng.u8(..)).take(10_000).collect(); +``` + +## 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. |