while_let_on_iterator Suggesting invalid Code With Refutable Pattern

[ironhaven]

When using a while let loop to get the results from the windows function clippy suggests that the while let be replaced with a regular for loop but a regular for loop will not compile because the pattern matches against a slice which has more possibilities.

Code

fn main() {
    let list = ["nail", "shoe", "horse"];
    let mut buf = String::new();
    let mut windows = list.windows(2);
    while let Some([first, second]) = windows.next() {
    //for [first, second] in windows {
     buf.push_str(&format!(
            "For want of a {} the {} was lost.\n",
            first, second
        ));
    }
    print!("{}", buf);
}

Clippy Output

warning: this loop could be written as a `for` loop
 --> src/lib.rs:4:39
  |
4 |     while let Some([first, second]) = windows.next() {
  |                                       ^^^^^^^^^^^^^^ help: try: `for [first, second] in windows { .. }`
  |
  = note: `#[warn(clippy::while_let_on_iterator)]` on by default
  = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#while_let_on_iterator

Version

I can replicate with the clippy on the rust playground and my local clippy (clippy 0.0.212 (6651c1b 2020-04-15)
Playground Link

[flip1995]

Fixed in #5559, but has to be deployed to nightly.

[ironhaven]

I saw that issue but i thought it must have not worked for all cases because it still gave bad output. I should have tested on nightly clippy before reporting. Thanks!