Implement fastrlp traits for Bytes (#1443)

* implement fastrlp traits for Bytes

* cargo fmt

* bump fastrlp to 0.1.2

ethers-core/src/types/bytes.rs

@@ -1,6 +1,5 @@
+use fastrlp::{Decodable, Encodable};
 use serde::{Deserialize, Deserializer, Serialize, Serializer};
-use thiserror::Error;
-
 use std::{
     borrow::Borrow,
     clone::Clone,
@@ -8,6 +7,7 @@ use std::{
     ops::Deref,
     str::FromStr,
 };
+use thiserror::Error;
 
 /// Wrapper type around Bytes to deserialize/serialize "0x" prefixed ethereum hex strings
 #[derive(Clone, Debug, Default, PartialEq, Eq, Hash, Serialize, Deserialize, Ord, PartialOrd)]
@@ -131,6 +131,21 @@ impl PartialEq<bytes::Bytes> for Bytes {
     }
 }
 
+impl Encodable for Bytes {
+    fn length(&self) -> usize {
+        self.0.length()
+    }
+    fn encode(&self, out: &mut dyn bytes::BufMut) {
+        self.0.encode(out)
+    }
+}
+
+impl Decodable for Bytes {
+    fn decode(buf: &mut &[u8]) -> Result<Self, fastrlp::DecodeError> {
+        Ok(Self(bytes::Bytes::decode(buf)?))
+    }
+}
+
 #[derive(Debug, Clone, Error)]
 #[error("Failed to parse bytes: {0}")]
 pub struct ParseBytesError(String);