use std;
import std::vec;

fn main() {
    let v =
        std::vec::map2({|i, b| if b { -i } else { i } }, [1, 2, 3, 4, 5],
                       [true, false, false, true, true]);
    log_err v;
    assert (v == [-1, 2, 3, -4, -5]);
}