Merge remote-tracking branch 'origin/unstable' into tree-states

consensus/tree_hash/Cargo.toml

@@ -2,7 +2,7 @@
 name = "tree_hash"
 version = "0.4.1"
 authors = ["Paul Hauner <paul@paulhauner.com>"]
-edition = "2018"
+edition = "2021"
 license = "Apache-2.0"
 description = "Efficient Merkle-hashing as used in Ethereum 2.0"
 

consensus/tree_hash/src/merkle_hasher.rs

@@ -376,8 +376,8 @@ mod test {
     fn compare_with_reference(leaves: &[Hash256], depth: usize) {
         let reference_bytes = leaves
             .iter()
-            .map(|hash| hash.as_bytes().to_vec())
-            .flatten()
+            .flat_map(|hash| hash.as_bytes())
+            .copied()
             .collect::<Vec<_>>();
 
         let reference_root = merkleize_padded(&reference_bytes, 1 << (depth - 1));