Partial application fun in Rust

partial_application.rs

#[macro_use]
extern crate partial_application;

enum Ops {
    Add, Sub, Div, Mult
} 

fn calc(op: Ops, x: i32, y: i32) -> i32 {
    match op {
        Ops::Add => x + y,
        Ops::Sub => x - y,
        Ops::Div => x / y,
        Ops::Mult => x * y
    }
}

fn main() {
    let div_by_two = partial!(calc => Ops::Div, _, 2);
    let times_three = partial!(calc => Ops::Mult, _, 3);

    let xs = [10, 30, 42, 4, 6];
    let _qs: Vec<i32> = xs
        .iter()
        .cloned()
        .map(div_by_two)
        .map(times_three)
        .inspect(|x| println!("{}", x))
        .collect();
}