Rust Option Bind

bind.rs

// Option bind for rust 0.10

fn inv(f: f32) -> Option<f32> {
    if f == 0.0 {
        None
    } 
    else {
        Some(1.0 / f)
    } 
}

fn bind<A, B>(o: Option<A>, f: fn(A) -> Option<B>) -> Option<B> {
    match o {
        Some(x) => f(x),
        None    => None
    }
}

fn main() {
    println!("{}", bind(Some(2.0), inv))
    println!("{}", bind(Some(0.0), inv))
}

To build and run, enter

rustc bind.rs && ./bind