| commit | 55a414d1b7efb0e4e4531dc2927ec2b98f764ec9 | [log] [tgz] |
|---|---|---|
| author | James Farrell <jamesfarrell@google.com> | Tue Aug 27 13:31:46 2024 +0000 |
| committer | James Farrell <jamesfarrell@google.com> | Tue Aug 27 13:31:46 2024 +0000 |
| tree | 38593a79432813e0f9bdc68d7b40d63591d311a2 | |
| parent | 0afef8ada87efcc430b2f89fb69d90c6eb9ae640 [diff] |
Migrate 25 crates to monorepo. env_logger epoll errno fallible-iterator fallible-streaming-iterator fastrand flagset fragile fs-err futures futures-core futures-executor futures-io futures-macro futures-sink futures-task futures-test futures-util gbm getrandom glob googletest googletest_macro h2 hashbrown Bug: 339424309 Test: treehugger Change-Id: Ia56f96917c7e6aa0dc76e309c1eaa5de88780890
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.