gistfile1.rs

extern crate collections;
use collections::HashMap;
use std::hash::Hash;

fn main() {
    let mut map: CountedSet<&'static str> = CountedSet::new();
    let strings = ["this", "is", "a", "list", "of", "of", "strings"];
    for k in strings.iter() {
         map.add(*k);
    }
    println!("{:?}", map)
}

struct CountedSet<T> {
    data: HashMap<T, uint>
}

impl<T: Hash + TotalEq> CountedSet<T> {
    fn add<T>(&self, k: T) -> T {
        self.data.insert_or_update_with(k, 1u, |_, v| *v += 1);
    }

    fn new() -> CountedSet<T> {
        CountedSet{data: HashMap::new()}
    }
}