add an assert and remove an iter_mut in reference_impl

Suggested in https://github.com/rust-lang/rust-clippy/issues/8039.

1 files changed, 3 insertions, 2 deletions

diff --git a/reference_impl/reference_impl.rs b/reference_impl/reference_impl.rs
index e669f36..83ac795 100644
--- a/reference_impl/reference_impl.rs
+++ b/reference_impl/reference_impl.rs
@@ -125,8 +125,9 @@ fn first_8_words(compression_output: [u32; 16]) -> [u32; 8] {
 }
 
 fn words_from_little_endian_bytes(bytes: &[u8], words: &mut [u32]) {
-    for (bytes_block, word) in bytes.chunks_exact(4).zip(words.iter_mut()) {
-        *word = u32::from_le_bytes(bytes_block.try_into().unwrap());
+    debug_assert_eq!(bytes.len(), 4 * words.len());
+    for (four_bytes, word) in bytes.chunks_exact(4).zip(words) {
+        *word = u32::from_le_bytes(four_bytes.try_into().unwrap());
     }
 }