Slice patterns don't work with non-Copy types

[cake4289]

Slice patterns cannot be used to destructure arrays of non-Copy types:

struct Struct;

fn main() {
    let x = [Struct, Struct];
    let [a, b] = x;
}

error[E0382]: use of moved value: `x[..]`
 --> src/main.rs:5:13
  |
5 |     let [a, b] = x;
  |          -  ^ value used here after move
  |          |
  |          value moved here
  |
  = note: move occurs because `x[..]` has type `Struct`, which does not implement the `Copy` trait

This makes array destructuring pretty redundant IMHO as moving out of a Copy array could already be done through indexing; moving out of a non-Copy array cannot be done but destructuring provides a safe syntax to do so.

On a related note, the following code fails to compile:

struct Struct;

fn main() {
    let x = [Struct, Struct];
    let a = x[0];
}

This should at the very least compile in the same way as

struct Struct;

fn main() {
    let x = [Struct, Struct];
    let [a, _] = x;
}

Which does compile correctly in rust 1.26.

[csmoe]

Duplicate of #26736

[vandenheuvel]

I'm not sure that this is really a duplicate, as #26736 is now resolved but the above example fails to compile on 1.45.0-nightly (2020-05-27 664fcd3f046e2a682460).