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+# 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];
+```
+
+Sample values from an array with `O(n)` complexity (`n` is the length of array):
+
+```rust
+fastrand::choose_multiple(vec![1, 4, 5].iter(), 2);
+fastrand::choose_multiple(0..20, 12);
+```
+
+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();
+```
+
+This crate aims to expose a core set of useful randomness primitives. For more niche algorithms, consider using the [`fastrand-contrib`] crate alongside this one.
+
+# Features
+
+- `std` (enabled by default): Enables the `std` library. This is required for the global
+ generator and global entropy. Without this feature, [`Rng`] can only be instantiated using
+ the [`with_seed`](https://docs.rs/fastrand/latest/fastrand/struct.Rng.html#method.with_seed) method.
+- `js`: Assumes that WebAssembly targets are being run in a JavaScript environment.
+
+[`fastrand-contrib`]: https://crates.io/crates/fastrand-contrib
+
+## 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.