3n+1 conjecture in generic rust

collatz.rs

use num::{Integer};
use std::ops::{MulAssign, DivAssign, AddAssign};

struct Collatz<T>(T);

impl<T> Iterator for Collatz<T> 
    where T: Integer + MulAssign + DivAssign + AddAssign + Clone,
{
    type Item = T;
    fn next(&mut self) -> Option<T> {
        if self.0.is_one() || self.0.is_zero() { return None }
        if self.0.is_even() {
            self.0 /= T::one() + T::one();
        } else {
            self.0 *= T::one() + T::one() + T::one();
            self.0 += T::one();
        }
        Some(self.0.clone())
    }
}