schwartzian-transform.rs

let new_col: Vec<&str> = col.iter().map(|&a| {
    (a, 1)
}).sort_by(|&a, &b| {
    a.1.cmp(&b.1)
}).map(|(col, _score)| col ).collect();

sort_by.rs

extern crate core;
extern crate collections;

use core::cmp::Ordering;
use collections::vec::IntoIter;

pub trait SortIterator<A, I>: Iterator {
    fn sort_by<F>(self, compare: F) -> IntoIter<A> where F: FnMut(&A, &A) -> Ordering;
}

impl<A, I: Iterator<Item=A>> SortIterator<A, I> for I {
    fn sort_by<F>(self, compare: F) -> IntoIter<A>
        where F: FnMut(&A, &A) -> Ordering,
    {
        let mut v: Vec<A> = self.collect();

        v.sort_by(compare);
        v.into_iter()
    }
}

fn main() {
    let col = ["b", "a"];

    let new_col: Vec<&str> = col.iter().sort_by(|&a, &b| {
        a.cmp(b)
    }).map(|&a| a ).collect();

    for i in new_col.iter() {
        println!("i = {}", i);
    }
}