Cargo.toml

[package]
name = "rand_experiment"
version = "0.1.0"
authors = ["Simon Coffey <simon.coffey@futurelearn.com>"]
edition = "2018"

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies]
rand = "0.6.5"
rand_xoshiro = "0.3.0"

main.rs

use rand::Rng;
use rand_xoshiro::rand_core::*;
use rand_xoshiro::Xoshiro256StarStar;

fn wat<R: Rng>(rng: &mut R) -> f64 {
    rng.gen()
}

fn main() {
    let mut rng = Xoshiro256StarStar::seed_from_u64(0);

    for i in 0..100 {
        let x: f64 = wat(&mut rng);
        println!("Random: {}", x);
    }
}

output.txt

   Compiling rand_experiment v0.1.0 (/Users/simon/dev/personal/computation_club/rand_experiment)
error[E0277]: the trait bound `rand_xoshiro::xoshiro256starstar::Xoshiro256StarStar: rand_core::RngCore` is not satisfied
  --> src/main.rs:13:22
   |
13 |         let x: f64 = wat(&mut rng);
   |                      ^^^ the trait `rand_core::RngCore` is not implemented for `rand_xoshiro::xoshiro256starstar::Xoshiro256StarStar`
   |
   = note: required because of the requirements on the impl of `rand::Rng` for `rand_xoshiro::xoshiro256starstar::Xoshiro256StarStar`
note: required by `wat`
  --> src/main.rs:5:1
   |
5  | fn wat<R: Rng>(rng: &mut R) -> f64 {
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: aborting due to previous error

For more information about this error, try `rustc --explain E0277`.
error: Could not compile `rand_experiment`.

To learn more, run the command again with --verbose.