The `shuffle` function never shuffles the first element into the first spot.

[bwinton]

Running the code:

use macroquad::{logging as log, rand::ChooseRandom};

#[macroquad::main(window_conf)]
async fn main() {
    let mut results = [0;4];
    for _ in 0..100 {
        let mut test = vec![0,1,2,3];
        test.shuffle();
        results[test[0]] += 1;
    }
    log::info!("results: {:?}", results);
}

consistently gives the output:

results: [0, 39, 33, 28]

whereas I'd expect something more like:

results: [25, 26, 25, 24]

[bwinton]

(I added a copy-ish of the function to my code that looks like:

pub trait ChooseRandom<T> {
    fn shuffle(&mut self);
}

impl<T> ChooseRandom<T> for Vec<T> {
    fn shuffle(&mut self) {
        for i in (1..self.len()).rev() {
            let j = gen_range(0, i+1);
            self.swap(i, j);
        }
    }
}

and that gives much better results, for what it's worth. 🙂)