commit | 694a98e77839899bfd868d5f8c78ea7bd765554f | [log] [tgz] |
---|---|---|
author | Ted Bauer <[email protected]> | Fri Mar 29 00:18:19 2024 +0000 |
committer | Automerger Merge Worker <[email protected]> | Fri Mar 29 00:18:19 2024 +0000 |
tree | 4b4a955cff1d6e590bc0eb361edba567c42cd7a1 | |
parent | c960d50af94c976a4725c1a87618bce071c7bfdb [diff] | |
parent | 9c7174c06ad5aa249ed9acde6bb68ee17b79dfa5 [diff] |
Make crate apex-available am: c7c9c6a948 am: 9c7174c06a Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/fastrand/+/3018244 Change-Id: I1bf19de9afd257eb6290ea5387a8a518e1d63c31 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];
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.