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1 rand
2 ====
3
4 A Rust library for random number generators and other randomness functionality.
5
6 [![Build Status](https://travis-ci.org/rust-lang-nursery/rand.svg?branch=master)](https://travis-ci.org/rust-lang-nursery/rand)
7 [![Build status](https://ci.appveyor.com/api/projects/status/rm5c9o33k3jhchbw?svg=true)](https://ci.appveyor.com/project/alexcrichton/rand)
8
9 [Documentation](https://doc.rust-lang.org/rand)
10
11 ## Usage
12
13 Add this to your `Cargo.toml`:
14
15 ```toml
16 [dependencies]
17 rand = "0.3"
18 ```
19
20 and this to your crate root:
21
22 ```rust
23 extern crate rand;
24 ```
25
26 ## Examples
27
28 There is built-in support for a random number generator (RNG) associated with each thread stored in thread-local storage. This RNG can be accessed via thread_rng, or used implicitly via random. This RNG is normally randomly seeded from an operating-system source of randomness, e.g. /dev/urandom on Unix systems, and will automatically reseed itself from this source after generating 32 KiB of random data.
29
30 ```rust
31 let tuple = rand::random::<(f64, char)>();
32 println!("{:?}", tuple)
33 ```
34
35 ```rust
36 use rand::Rng;
37
38 let mut rng = rand::thread_rng();
39 if rng.gen() { // random bool
40 println!("i32: {}, u32: {}", rng.gen::<i32>(), rng.gen::<u32>())
41 }
42 ```
43
44 It is also possible to use other RNG types, which have a similar interface. The following uses the "ChaCha" algorithm instead of the default.
45
46 ```rust
47 use rand::{Rng, ChaChaRng};
48
49 let mut rng = rand::ChaChaRng::new_unseeded();
50 println!("i32: {}, u32: {}", rng.gen::<i32>(), rng.gen::<u32>())
51 ```
52