rs-number_traits

number traits

```rust extern crate number_traits;

use number_traits::{Num, Sqrt};

fn add(a: T, b: T) -> T where T: Num, { a + b }

fn sqrt(x: T) -> T where T: Sqrt, { x.sqrt() }

fn main() { asserteq!(add(2, 2), 4); asserteq!(sqrt(4), 2); } ```