| commit | e614fb34c8c00b82be77f1d255a53851d8c4d013 | [log] [tgz] |
|---|---|---|
| author | Jeff Vander Stoep <[email protected]> | Thu Feb 08 14:16:51 2024 +0000 |
| committer | Automerger Merge Worker <[email protected]> | Thu Feb 08 14:16:51 2024 +0000 |
| tree | be0a0b57e7d325816decfc234bb5ebbbd13965ca | |
| parent | 6401b4a593ec1c8182ab00fc9f0ce7a2d15f8cc2 [diff] | |
| parent | f00a459d95e87096a8366dc67f5fbfdf33a4e205 [diff] |
Upgrade fastrand to 2.0.1 am: f00a459d95 Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/fastrand/+/2953856 Change-Id: Ifbd87bc93feedac2e3de1fcf5b3b2c14c13fa934 Signed-off-by: Automerger Merge Worker <[email protected]>
A simple and fast random number generator.
The implementation uses Wyrand, a simple and fast generator but not cryptographically secure.
Flip a coin:
if fastrand::bool() { println!("heads"); } else { println!("tails"); }
Generate a random i32:
let num = fastrand::i32(..);
Choose a random element in an array:
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):
fastrand::choose_multiple(vec![1, 4, 5].iter(), 2); fastrand::choose_multiple(0..20, 12);
Shuffle an array:
let mut v = vec![1, 2, 3, 4, 5]; fastrand::shuffle(&mut v);
Generate a random Vec or String:
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:
// 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:
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.
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 method.js: Assumes that WebAssembly targets are being run in a JavaScript environment.Licensed under either of
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.