From 6477b2ad69fde88002921dbf51128c53590ced78 Mon Sep 17 00:00:00 2001
From: debris <marek.kotewicz@gmail.com>
Date: Fri, 27 Nov 2015 18:15:44 +0100
Subject: [PATCH] implements "bytes" for all fixed size arrays

---
 src/bytes.rs | 17 +++++++++++++++++
 src/sha3.rs  |  5 +++--
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/src/bytes.rs b/src/bytes.rs
index 73592643d..870c9eef3 100644
--- a/src/bytes.rs
+++ b/src/bytes.rs
@@ -22,9 +22,26 @@ impl BytesConvertable for Vec<u8> {
 	fn bytes(&self) -> &[u8] { self }
 }
 
+macro_rules! impl_bytes_convertable_for_array {
+    ($zero: expr) => ();
+    ($len: expr, $($idx: expr),*) => {
+        impl BytesConvertable for [u8; $len] {
+            fn bytes(&self) -> &[u8] { self }
+        }
+        impl_bytes_convertable_for_array! { $($idx),* }
+    }
+}
+
+// two -1 at the end is not expanded
+impl_bytes_convertable_for_array! {
+        32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16,
+        15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0, -1
+}
+
 #[test]
 fn bytes_convertable() {
 	assert_eq!(vec![0x12u8, 0x34].bytes(), &[0x12u8, 0x34]);
+    assert_eq!([0u8; 0].bytes(), &[]);
 }
 
 /// TODO: optimise some conversations
diff --git a/src/sha3.rs b/src/sha3.rs
index 61c5c26f8..e2866d288 100644
--- a/src/sha3.rs
+++ b/src/sha3.rs
@@ -20,10 +20,11 @@ impl<T> Hashable for T where T: BytesConvertable {
 #[test]
 fn sha3_empty() {
 	use std::str::FromStr;
-	assert_eq!((&[0u8; 0][..]).sha3(), H256::from_str("c5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470").unwrap());
+	assert_eq!([0u8; 0].sha3(), H256::from_str("c5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470").unwrap());
 }
 #[test]
 fn sha3_as() {
 	use std::str::FromStr;
-	assert_eq!((&[0x41u8; 32][..]).sha3(), H256::from_str("59cad5948673622c1d64e2322488bf01619f7ff45789741b15a9f782ce9290a8").unwrap());
+	assert_eq!([0x41u8; 32].sha3(), H256::from_str("59cad5948673622c1d64e2322488bf01619f7ff45789741b15a9f782ce9290a8").unwrap());
 }
+