| commit | 753c219bfa0eb74635ed3d6af16b4bd4c45b9254 | [log] [tgz] |
|---|---|---|
| author | Android Build Coastguard Worker <[email protected]> | Thu Sep 21 22:01:14 2023 +0000 |
| committer | Android Build Coastguard Worker <[email protected]> | Thu Sep 21 22:01:14 2023 +0000 |
| tree | 1335b12c1234e96ca6fbaa9153c7c0f55f5c7761 | |
| parent | 844f82ea749cf99f1ed4eace18fdcdbb765b56dd [diff] | |
| parent | 8be0dcf87521f05f06870c940fc35d813c371fe8 [diff] |
Snap for 10843824 from 8be0dcf87521f05f06870c940fc35d813c371fe8 to 24Q1-release Change-Id: I544c865319822a40a00fb1e5079b6c2e24341f51
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];
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();
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.