enumerate_generic.rs

use num_traits::{Zero, One};
use std::ops::{AddAssign};

fn enumerate_generic<T>() -> impl Iterator<Item = T>
where
    T: Clone + Zero + One + AddAssign,
{
    let mut curr = T::zero();
    std::iter::repeat_with(move || {
        let next = curr.clone();
        curr += T::one();
        next
    })
}

fn main() {
    let foos: Vec<u64> = enumerate_generic().take(10).collect();
    println!("{:?}", foos);
}