&{integer} is incorrectly inferenced to i32

[nonzerofloat]

fn main() {
    let v = gen(1000);
    println!("{:?}", v);
    assert_eq!(gen(1_000_000_000).len(), 1023);
}

fn gen(n: u64) -> Vec<u64> {
    let mut v = vec![0];
    let mut i = 0;
    let mut len = 1;
    let mut w = 1;
    loop {
        for k in [4, 7].into_iter() {
            let mut x = i;
            let y = i + len;
            while x < y {
                let z = k * w + v[x];
                if n < z {
                    return v;
                }
                v.push(z);
                x += 1;
            }
        }
        w *= 10;
        i += len;
        len *= 2;
    }
}

https://play.rust-lang.org/?version=stable&mode=debug&edition=2018&gist=81011b06836fc24bd4649a9358207ba9

Expected output:

[0, 4, 7, 44, 47, 74, 77, 444, 447, 474, 477, 744, 747, 774, 777]

Instead, I get:

   Compiling playground v0.0.1 (/playground)
error[E0277]: cannot add `u64` to `i32`
  --> src/main.rs:17:31
   |
17 |                 let z = k * w + v[x];
   |                               ^ no implementation for `i32 + u64`
   |
   = help: the trait `std::ops::Add<u64>` is not implemented for `i32`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0277`.
error: could not compile `playground`.

When I change the for line for k in [4, 7].into_iter() { to for k in [4, 7].into_iter().copied {, there's no compile error. I think there's a bug in type inference for &{integer}.

[nonzerofloat]

#57447

I checked the duplicate issue. I close this issue.