| commit | 9ba0a2d209459586da736e7b418500083bb62a52 | [log] [tgz] |
|---|---|---|
| author | Matthew Maurer <[email protected]> | Thu Mar 09 18:06:40 2023 +0000 |
| committer | Automerger Merge Worker <[email protected]> | Thu Mar 09 18:06:40 2023 +0000 |
| tree | db504e270310dcd06e1372842ea617bccc9a5852 | |
| parent | 91b82869ac7086351eae1dce21b1355b4b7a236b [diff] | |
| parent | f858fea5a2f6d8b657ae78a7740a43c3b8632ead [diff] |
Make fastrand available to product and vendor am: d106aef69e am: e6d3cd53a1 am: af3508b645 am: f858fea5a2 Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/fastrand/+/2476343 Change-Id: Ic6f951478b7dd35bac7c03359d84d360b468fd7d 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.