src/vendor/rand/README.md

   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://docs.rs/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
  53 # `derive(Rand)`
  54
  55 You can derive the `Rand` trait for your custom type via the `#[derive(Rand)]`
  56 directive. To use this first add this to your Cargo.toml:
  57
  58 ```toml
  59 rand = "0.3"
  60 rand-derive = "0.3"
  61 ```
  62
  63 Next in your crate:
  64
  65 ```rust
  66 extern crate rand;
  67 #[macro_use]
  68 extern crate rand_derive;
  69
  70 #[derive(Rand, Debug)]
  71 struct MyStruct {
  72     a: i32,
  73     b: u32,
  74 }
  75
  76 fn main() {
  77     println!("{:?}", rand::random::<MyStruct>());
  78 }
  79 ```
  80
  81
  82 # License
  83
  84 `rand` is primarily distributed under the terms of both the MIT
  85 license and the Apache License (Version 2.0), with portions covered by various
  86 BSD-like licenses.
  87
  88 See LICENSE-APACHE, and LICENSE-MIT for details.