src/vendor/rand-0.3.22/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 ## Compatibility upgrade
  12
  13 Version 0.3 has been replaced by a compatibility wrapper around `rand` 0.4. It
  14 is recommended to update to 0.4.
  15
  16 ## Usage
  17
  18 Add this to your `Cargo.toml`:
  19
  20 ```toml
  21 [dependencies]
  22 rand = "0.4"
  23 ```
  24
  25 and this to your crate root:
  26
  27 ```rust
  28 extern crate rand;
  29 ```
  30
  31 ## Examples
  32
  33 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.
  34
  35 ```rust
  36 let tuple = rand::random::<(f64, char)>();
  37 println!("{:?}", tuple)
  38 ```
  39
  40 ```rust
  41 use rand::Rng;
  42
  43 let mut rng = rand::thread_rng();
  44 if rng.gen() { // random bool
  45     println!("i32: {}, u32: {}", rng.gen::<i32>(), rng.gen::<u32>())
  46 }
  47 ```
  48
  49 It is also possible to use other RNG types, which have a similar interface. The following uses the "ChaCha" algorithm instead of the default.
  50
  51 ```rust
  52 use rand::{Rng, ChaChaRng};
  53
  54 let mut rng = rand::ChaChaRng::new_unseeded();
  55 println!("i32: {}, u32: {}", rng.gen::<i32>(), rng.gen::<u32>())
  56 ```
  57
  58 # `derive(Rand)`
  59
  60 You can derive the `Rand` trait for your custom type via the `#[derive(Rand)]`
  61 directive. To use this first add this to your Cargo.toml:
  62
  63 ```toml
  64 rand = "0.4"
  65 rand_derive = "0.3"
  66 ```
  67
  68 Next in your crate:
  69
  70 ```rust
  71 extern crate rand;
  72 #[macro_use]
  73 extern crate rand_derive;
  74
  75 #[derive(Rand, Debug)]
  76 struct MyStruct {
  77     a: i32,
  78     b: u32,
  79 }
  80
  81 fn main() {
  82     println!("{:?}", rand::random::<MyStruct>());
  83 }
  84 ```
  85
  86
  87 # License
  88
  89 `rand` is primarily distributed under the terms of both the MIT
  90 license and the Apache License (Version 2.0).
  91
  92 See LICENSE-APACHE, and LICENSE-MIT for details.