pub trait VecMore<T> {
    fn move_to<F>(&mut self, to: &mut Vec<T>, f: F)
    where
        F: FnMut(&T) -> bool;
}

impl<T> VecMore<T> for Vec<T> {
    fn move_to<F>(&mut self, to: &mut Vec<T>, mut f: F)
    where
        F: FnMut(&T) -> bool,
    {
        let len = self.len();
        let mut del = 0;
        {
            let v = &mut **self;

            for i in 0..len {
                if f(&v[i]) {
                    del += 1;
                } else if del > 0 {
                    v.swap(i - del, i);
                }
            }
        }
        if del > 0 {
            while del > 0 {
                let v = match self.pop() {
                    Some(v) => v,
                    None => break,
                };
                to.push(v);
                del -= 1;
            }
        }
    }
}