### What it does Checks for use of `.drain(..)` on `Vec` and `VecDeque` for iteration. ### Why is this bad? `.into_iter()` is simpler with better performance. ### Example ``` let mut foo = vec![0, 1, 2, 3]; let bar: HashSet = foo.drain(..).collect(); ``` Use instead: ``` let foo = vec![0, 1, 2, 3]; let bar: HashSet = foo.into_iter().collect(); ```