| commit | cf7cf2b64dc3f6a2de6ec79ff228e4a88c52e0c5 | [log] [tgz] |
|---|---|---|
| author | Android Build Coastguard Worker <[email protected]> | Tue Sep 10 23:09:36 2024 +0000 |
| committer | Android Build Coastguard Worker <[email protected]> | Tue Sep 10 23:09:36 2024 +0000 |
| tree | 38593a79432813e0f9bdc68d7b40d63591d311a2 | |
| parent | e41d818bc4d7acb1d821562d28e54988c8c489cd [diff] | |
| parent | 955b1092545fe08ba36b6fa7f58b7d3a3aa61411 [diff] |
Snap for 12349386 from 955b1092545fe08ba36b6fa7f58b7d3a3aa61411 to sdk-release Change-Id: I79754ce4df7305216fbf5945df3667e3712378a5
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.