| commit | 4bb8111a346477321796bcea2e42820b25f706dd | [log] [tgz] |
|---|---|---|
| author | Jeff Vander Stoep <[email protected]> | Thu Feb 23 14:47:11 2023 +0000 |
| committer | Automerger Merge Worker <[email protected]> | Thu Feb 23 14:47:11 2023 +0000 |
| tree | 7cb99e6175b4535041b4ef03b4e26d68bc944ba0 | |
| parent | 1c56eee63b003dfb8451b1d2032addbc97b94fc2 [diff] | |
| parent | 2ab4591102fbc4bd59b1d0c11e79ffd46c4d8a3f [diff] |
Add Android.bp am: 8ea5f7c86d am: 2ab4591102 Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/fastrand/+/2452805 Change-Id: I75a33e75e15fd197f904cee87a34fa231bddb160 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.