commit | e6136dc9e6dbc645d7b03b2891f3f6a41feb04b5 | [log] [tgz] |
---|---|---|
author | Andrew Walbran <qwandor@google.com> | Thu Nov 09 13:47:19 2023 +0000 |
committer | Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com> | Thu Nov 09 13:47:19 2023 +0000 |
tree | 63636b1121e171789dbab5226a6867fa3283af49 | |
parent | 8be0dcf87521f05f06870c940fc35d813c371fe8 [diff] | |
parent | 404eb3ea8b5345bbf6a6242ae3616e5892e0ddd2 [diff] |
Migrate to cargo_embargo. am: 6183a6076e am: 60d73396dc am: 404eb3ea8b Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/fastrand/+/2822398 Change-Id: I2d1e6eaffb18efa54ecc98c29e7118bdbc3eab1f Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
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.