//   http://static.rust-lang.org/doc/master/std/rand/trait.Rng.html

01  use std::rand;
02  use std::rand::Rng;
03
04  fn main() {
05    let mut rng = rand::task_rng();
06    let n: uint = rng.gen_range(0u, 10);
07    println!("{}", n);
08    let m: float = rng.gen_range(-40.0, 1.3e5);
09    println!("{}", m);
10  }

test_rand002.rs:6:17: 6:39 error: type `@mut std::rand::IsaacRng` does not
implement any method in scope named `gen_range`
test_rand002.rs:6    let n: uint = rng.gen_range(0u, 10);
                               ^~~~~~~~~~~~~~~~~~~~~~
test_rand002.rs:8:18: 8:46 error: type `@mut std::rand::IsaacRng` does not
implement any method in scope named `gen_range`
test_rand002.rs:8    let m: float = rng.gen_range(-40.0, 1.3e5);
                                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
error: aborting due to 2 previous errors

use std::rand;
use std::rand::Rng;

fn main() {
   let mut rng = rand::task_rng();
   let x: uint = rng.gen();
   println!("{}", x);
   println!("{:?}", rng.gen::<(f64, bool)>());
}

use std::rand::{task_rng, Rng};

fn main() {
    // a number from [-40.0, 13000.0)
    let num: f64 = task_rng().gen_range(-40.0, 1.3e4);
    println!("{}", num);
}

extern crate rand;
use rand::Rng;
fn main(){
    let num = rand::thread_rng().gen_range(0, 100);
    println!("{}", num);
}

extern crate rand;
use rand::distributions::{IndependentSample, Range};

fn main() {
  let step =  Range::new(0, 50);
  let mut rng = rand::thread_rng();
  let choice = step.ind_sample(&mut rng);
  println!("{}", choice);
}