extern crate num_bigint; // 0.2.2

use std::ops::Add;
use num_bigint::BigInt;

fn fib<T: Add<Output=T> + Clone>(one: T, n: usize) -> T {
    let mut t = (one.clone(), one);
    for _ in 0 .. n {
        t = (t.0.clone() + t.1, t.0);
    }
    t.1
}

fn main() {
    println!("f32: {}", fib(1f32, 7));
    println!("fu8: {}", fib(1u8, 7));
    println!("usize: {}", fib(1usize, 7));
    println!("BigInt: {}", fib(BigInt::from(1), 700));
}