fn iter_vec<T>(v: [T], f: block(T)) { for x: T in v { f(x); } }

fn main() {
    let v = [1, 2, 3, 4, 5];
    let sum = 0;
    iter_vec(v, {|i| iter_vec(v, {|j| log_err i * j; sum += i * j; }); });
    log_err sum;
    assert (sum == 225);
}