commit | eaedee1f091904d77177e292cd135f68e2779e59 | [log] [tgz] |
---|---|---|
author | Android Build Coastguard Worker <android-build-coastguard-worker@google.com> | Fri Mar 10 05:15:23 2023 +0000 |
committer | Android Build Coastguard Worker <android-build-coastguard-worker@google.com> | Fri Mar 10 05:15:23 2023 +0000 |
tree | db504e270310dcd06e1372842ea617bccc9a5852 | |
parent | f1cd22544f79fa72e1707364ec1cba1e39558b7a [diff] | |
parent | 9ba0a2d209459586da736e7b418500083bb62a52 [diff] |
Snap for 9722771 from 9ba0a2d209459586da736e7b418500083bb62a52 to udc-d1-release Change-Id: I88de389d9417901507afe9c90344d183a86eb269
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.