How to do it...

1. Open the Cargo.toml file that was generated earlier for you
2. Under [dependencies], add the following line:

rand = "0.3"

3. If you want, you can go to rand's crates.io page (https://crates.io/crates/rand) to check for the newest version and use that one instead

4. In the bin folder, create a file called rand.rs

5. Add the following code and run it with cargo run --bin rand:

1   extern crate rand;
2 
3   fn main() {
4     // random_num1 will be any integer between
5     // std::i32::MIN and std::i32::MAX
6     let random_num1 = rand::random::<i32>();
7     println!("random_num1: {}", random_num1);
8     let random_num2: i32 = rand::random();
9     println!("random_num2: {}", random_num2);
10    // The initialization of random_num1 and random_num2
11    // is equivalent.
12 
13    // Every primitive data type can be randomized
14    let random_char = rand::random::<char>();
15    // Altough random_char will probably not be
16    // representable on most operating systems
17    println!("random_char: {}", random_char);
18 
19 
20    use rand::Rng;
21    // We can use a reusable generator
22    let mut rng = rand::thread_rng();
23    // This is equivalent to rand::random()
24    if rng.gen() {
25      println!("This message has a 50-50 chance of being
                  printed");
26    }
27    // A generator enables us to use ranges
28    // random_num3 will be between 0 and 9
29    let random_num3 = rng.gen_range(0, 10);
30    println!("random_num3: {}", random_num3);
31 
32    // random_float will be between 0.0 and 0.999999999999...
33    let random_float = rng.gen_range(0.0, 1.0);
34    println!("random_float: {}", random_float);
35 
36    // Per default, the generator uses a uniform distribution,
37    // which should be good enough for nearly all of your
38    // use cases. If you require a particular distribution,
39    // you specify it when creating the generator:
40    let mut chacha_rng = rand::ChaChaRng::new_unseeded();
41    let random_chacha_num = chacha_rng.gen::<i32>();
42    println!("random_chacha_num: {}", random_chacha_num);
43  }