argh, I thought the depreciation is compounded ):

oh and this was done for rust

fn array_diff<T: PartialEq>(a: Vec<T>, b: Vec<T>) -> Vec<T> {
    a.iter()
        .filter(|incoming| !b.contains(incoming))
        .collect::<Vec<T>>()
}

I am having problem with the ownership, and the last collect() wouldn't work, may I know what went wrong?