🛡️ GHSA-83gg-pwxf-jr89 — array-macro

array! macro is unsound in presence of traits that implement methods it calls internally

Affected versions of this crate called some methods using auto-ref. The affected code looked like this.

```rust

let mut arr = $crate::__core::mem::MaybeUninit::uninit();

let mut vec = $crate::__ArrayVec::<T>::new(arr.as_mut_ptr() as *mut T);

```

In this case, the problem is that as_mut_ptr is a method of &mut MaybeUninit, not MaybeUninit. This made it possible for traits to hijack the method calls in order to cause unsoundness.

```rust

trait AsMutPtr<T> {

fn as_mut_ptr(&self) -> *mut T;

}

impl<T> AsMutPtr<T> for std::mem::MaybeUninit<T> {

fn as_mut_ptr(&self) -> *mut T {

std::ptr::null_mut()

}

}

array![0; 1];

```

The flaw was corrected by explicitly referencing variables in macro body in order to avoid auto-ref.