letters.rs

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

    let _filtered_letters: Vec<&str> = letters.iter().map(|letter| {
        (letter, 1)
    }).filter(|&(_letter, score)| {
        score > 0
    }).map(|(letter, _score)| {
        // I don't want to have to clone() here
        letter
    }).collect();
}

zzz-error.out

letters.rs:12:8: 12:17 error: the trait `core::iter::FromIterator<&&str>` is not implemented for the type `collections::vec::Vec<&str>` [E0277]
collect.rs:12     }).collect();
                     ^~~~~~~~~
letters.rs:12:8: 12:17 note: a collection of type `collections::vec::Vec<&str>` cannot be built from an iterator over elements of type `&&str`
letters.rs:12     }).collect();
                     ^~~~~~~~~
error: aborting due to previous error