fn main() {

    let f1 = Foo {};
    let f2 = Foo {};
    let f3 = Foo {};

    let mut vec = vec![];

    vec.push(f1);
    vec.push(f2);
    vec.push(f3);

    for v in vec.iter() {
        let mut v = &v;
        // how do i pass this value as &mut reference
        // when i obtained the & reference from iterator
        need_mut_reference(&mut v);
    }
}



fn need_mut_reference(foo: &mut Foo) {

}


struct Foo {

}