weighted_gen.rs

struct WeightedValueGen<'a, T, const N: usize> {
    values: [&'a T; N],
    weights: [f32; N],
}

impl<'a, T, const N: usize> WeightedValueGen<'a, T, N> {
    #[allow(dead_code, unused_mut)]
    fn new(input: &'a [(T, f32); N]) -> Self {
        let mut values = unsafe {
            let mut values: [mem::MaybeUninit<&T>; N] = mem::MaybeUninit::uninit().assume_init();
            for i in 0..values.len() {
                std::ptr::write(values[i].as_mut_ptr(), &input[i].0);
            }
            (&*(&mem::MaybeUninit::new(values) as *const _ as *const mem::MaybeUninit<_>))
                .assume_init_read()
        };

        let weights = build_weight_arr(input);
        Self { values, weights }
    }

    #[allow(dead_code)]
    pub fn get_value(&self) -> &T {
        let idx = get_rand_index(rnd_point, &self.weights);
        &self.values[idx]
    }
}