Use MaybeUninit to init array without heap allocation

src/array/fixed_size_list.rs

@@ -263,12 +263,28 @@ impl<const N: usize, I: IntoIterator> Iterator for FixedSizeArrayChunks<N, I> {
     type Item = [I::Item; N];
 
     fn next(&mut self) -> Option<Self::Item> {
+        let mut data: [MaybeUninit<I::Item>; N] =
+        // Safety:
+        // - https://doc.rust-lang.org/stable/std/mem/union.MaybeUninit.html#initializing-an-array-element-by-element
+         unsafe { MaybeUninit::uninit().assume_init() };
+
+        let mut total_elements_written: usize = 0;
         self.iter
             .by_ref()
             .take(N)
-            .collect::<Vec<_>>()
-            .try_into()
-            .ok()
+            .enumerate()
+            .for_each(|(array_index, val)| {
+                data[array_index].write(val);
+                total_elements_written += 1;
+            });
+
+        (total_elements_written == N).then(|| {
+            data.map(|item| {
+                // Safety:
+                // - We only initialize if the number of elements that were written are actually N.
+                unsafe { item.assume_init() }
+            })
+        })
     }
 }