fn get_temp(temps: Vec<f64>) -> f64 {
    let mut valid_temps: Vec<f64> = Vec::with_capacity(8);

    for t in temps {
        valid_temps.push(t);
    }

    return valid_temps.iter().sum::<f64>() / valid_temps.len() as f64
}

fn main() {
    let temps: Vec<f64> = vec![50.0, 45.1, 32.9, 45.1, 43.3, 46.56, 43.6, 23.3];
    assert!(!get_temp(temps).is_nan());

    let temps: Vec<f64> = vec![50.0];
    assert_eq!(50.0, get_temp(temps));

    // divide by zero results in `NaN`
    let temps: Vec<f64> = vec![];
    assert!(get_temp(temps).is_nan());
}