Add bytes::Bytes implementation

.gitlab-ci.yml

@@ -51,14 +51,14 @@ check-rust-stable-no_derive_no_std_full:
   stage:                           check
   <<:                              *docker-env
   script:
-    - time cargo +stable check --verbose --no-default-features --features bit-vec,generic-array,full
+    - time cargo +stable check --verbose --no-default-features --features bit-vec,bytes,generic-array,full
     - sccache -s
 
 check-rust-stable-no_derive_no_std:
   stage:                           check
   <<:                              *docker-env
   script:
-    - time cargo +stable check --verbose --no-default-features --features bit-vec,generic-array
+    - time cargo +stable check --verbose --no-default-features --features bit-vec,bytes,generic-array
     - sccache -s
 
 check-rust-stable-no_std-chain-error:
@@ -72,7 +72,7 @@ check-rust-stable-no_derive_full:
   stage:                           check
   <<:                              *docker-env
   script:
-    - time cargo +stable check --verbose --features bit-vec,generic-array,full
+    - time cargo +stable check --verbose --features bit-vec,bytes,generic-array,full
     - sccache -s
 
 #### stage:                        test
@@ -81,21 +81,21 @@ test-rust-stable:
   stage:                           test
   <<:                              *docker-env
   script:
-    - time cargo +stable test --verbose --all --features bit-vec,generic-array,derive,max-encoded-len
+    - time cargo +stable test --verbose --all --features bit-vec,bytes,generic-array,derive,max-encoded-len
     - sccache -s
 
 test-rust-stable-no_derive:
   stage:                           test
   <<:                              *docker-env
   script:
-    - time cargo +stable test --verbose --features bit-vec,generic-array
+    - time cargo +stable test --verbose --features bit-vec,bytes,generic-array
     - sccache -s
 
 bench-rust-nightly:
   stage:                           test
   <<:                              *docker-env
   script:
-    - time cargo +nightly bench --features bit-vec,generic-array,derive
+    - time cargo +nightly bench --features bit-vec,bytes,generic-array,derive
     - sccache -s
 
 miri:
@@ -105,7 +105,7 @@ miri:
     RUST_BACKTRACE:                1
     MIRIFLAGS:                     "-Zmiri-disable-isolation"
   script:
-    - time cargo +nightly miri test --features bit-vec,generic-array,arbitrary --release
+    - time cargo +nightly miri test --features bit-vec,bytes,generic-array,arbitrary --release
 
 #### stage:                        build
 
@@ -118,5 +118,5 @@ build-linux-ubuntu-amd64:
     - if: $CI_COMMIT_REF_NAME == "master"
     - if: $CI_COMMIT_REF_NAME == "tags"
   script:
-    - cargo build --verbose --release --features bit-vec,generic-array,derive
+    - cargo build --verbose --release --features bit-vec,bytes,generic-array,derive
     - sccache -s

Cargo.toml

@@ -14,6 +14,7 @@ arrayvec = { version = "0.7", default-features = false }
 serde = { version = "1.0.102", optional = true }
 parity-scale-codec-derive = { path = "derive", version = "2.3.1", default-features = false, optional = true }
 bitvec = { version = "0.20.1", default-features = false, features = ["alloc"], optional = true }
+bytes = { version = "1", default-features = false, optional = true }
 byte-slice-cast = { version = "1.0.0", default-features = false }
 generic-array = { version = "0.14.4", optional = true }
 arbitrary = { version = "1.0.1", features = ["derive"], optional = true }

src/codec.rs

@@ -371,6 +371,23 @@ mod feature_full_wrapper_type_encode {
 	impl EncodeLike<String> for &str {}
 }
 
+#[cfg(feature = "bytes")]
+mod feature_wrapper_bytes {
+	use super::*;
+	use bytes::Bytes;
+
+	impl WrapperTypeEncode for Bytes {}
+	impl EncodeLike for Bytes {}
+	impl EncodeLike<&[u8]> for Bytes {}
+	impl EncodeLike<Vec<u8>> for Bytes {}
+	impl EncodeLike<Bytes> for &[u8] {}
+	impl EncodeLike<Bytes> for Vec<u8> {}
+
+	impl WrapperTypeDecode for Bytes {
+		type Wrapped = Vec<u8>;
+	}
+}
+
 impl<T, X> Encode for X where
 	T: Encode + ?Sized,
 	X: WrapperTypeEncode<Target = T>,
@@ -1429,6 +1446,19 @@ mod tests {
 		assert_eq!(<Vec<OptionBool>>::decode(&mut &encoded[..]).unwrap(), value);
 	}
 
+	#[cfg(feature = "bytes")]
+	#[test]
+	fn bytes_works_as_expected() {
+		let input = bytes::Bytes::from_static(b"hello");
+		let encoded = Encode::encode(&input);
+		let encoded_vec = input.to_vec().encode();
+		assert_eq!(encoded, encoded_vec);
+
+		assert_eq!(
+			&b"hello"[..],
+			bytes::Bytes::decode(&mut &encoded[..]).unwrap(),
+		);
+	}
 	fn test_encode_length<T: Encode + Decode + DecodeLength>(thing: &T, len: usize) {
 		assert_eq!(<T as DecodeLength>::len(&mut &thing.encode()[..]).unwrap(), len);
 	}

tests/max_encoded_len_ui/not_mel.stderr

@@ -1,5 +1,5 @@
 error[E0599]: the function or associated item `max_encoded_len` exists for struct `Generic<NotMel>`, but its trait bounds were not satisfied
-  --> $DIR/not_mel.rs:12:29
+  --> tests/max_encoded_len_ui/not_mel.rs:12:29
    |
 4  | struct NotMel;
    | -------------- doesn't satisfy `NotMel: MaxEncodedLen`
@@ -13,9 +13,23 @@ error[E0599]: the function or associated item `max_encoded_len` exists for struc
 12 |     let _ = Generic::<NotMel>::max_encoded_len();
    |                                ^^^^^^^^^^^^^^^ function or associated item cannot be called on `Generic<NotMel>` due to unsatisfied trait bounds
    |
-   = note: the following trait bounds were not satisfied:
-           `NotMel: MaxEncodedLen`
-           which is required by `Generic<NotMel>: MaxEncodedLen`
+note: the following trait bounds were not satisfied because of the requirements of the implementation of `MaxEncodedLen` for `_`:
+      `NotMel: MaxEncodedLen`
+  --> tests/max_encoded_len_ui/not_mel.rs:6:18
+   |
+6  | #[derive(Encode, MaxEncodedLen)]
+   |                  ^^^^^^^^^^^^^
+7  | struct Generic<T> {
+   |        ^^^^^^^^^^
+note: the following trait must be implemented
+  --> src/max_encoded_len.rs
+   |
+   | / pub trait MaxEncodedLen: Encode {
+   | |     /// Upper bound, in bytes, of the maximum encoded size of this item.
+   | |     fn max_encoded_len() -> usize;
+   | | }
+   | |_^
    = help: items from traits can only be used if the trait is implemented and in scope
    = note: the following trait defines an item `max_encoded_len`, perhaps you need to implement it:
            candidate #1: `MaxEncodedLen`
+   = note: this error originates in the derive macro `MaxEncodedLen` (in Nightly builds, run with -Z macro-backtrace for more info)