suggest .into_iter() instead of .iter() on containers if it's possible to remove clones?

fn main() {
    let v = vec![String::new(); 10];
    let bla: Vec<_> = v
        .iter() // over the vector
        .map(|s| {
            let v = s.clone().into_bytes();
// because "into_bytes() consumes s, we have to clone() s here
            v.len();
            v
        })
        .collect();
// but in the end, v is no longer used 
}

So we can rewrite this example to use .into_iter() instead of .iter() which has the 'advantage' of of consuming bla. This makes it clear that since we consume the vector, we can also safely consume the contained items and lets us remove the clone:

fn main() {
    let v = vec![String::new(); 10];
    let bla: Vec<_> = v
        .into_iter() // consume the vec
        .map(|s| {
            let v = s.into_bytes(); // consuming s is ok now.
            v.len();
            v
        })
        .collect();
// v has no use so it's save for consumption, nom
}

Start by comparing the two Rust examples and define when replacing .iter() with .into_iter() is safe and removes the clone. Done means Clippy can identify applicable container iterations, suggest the consuming form, and avoid suggesting it when the container or its elements are still needed.