staging-xcm: Use versioned_type! for VersionedXcm

polkadot/xcm/src/lib.rs

@@ -82,6 +82,36 @@ pub trait TryAs<T> {
 }
 
 macro_rules! versioned_type {
+	(@internal $n:ident, $v3:ty, $v4:ty,) => {
+		impl IntoVersion for $n {
+			fn into_version(self, n: Version) -> Result<Self, ()> {
+				Ok(match n {
+					1 | 2 => Self::V2(self.try_into()?),
+					3 => Self::V3(self.try_into()?),
+					4 => Self::V4(self.try_into()?),
+					_ => return Err(()),
+				})
+			}
+		}
+		impl MaxEncodedLen for $n {
+			fn max_encoded_len() -> usize {
+				<$v3>::max_encoded_len().max(<$v4>::max_encoded_len())
+			}
+		}
+	};
+	(@internal $n:ident, $v3:ty, $v4:ty, $t:ident) => {
+		// `VersionedXcm` version 1 support is dropped
+		impl<$t> IntoVersion for $n<$t>{
+			fn into_version(self, n: Version) -> Result<Self, ()> {
+				Ok(match n {
+					2 => Self::V2(self.try_into()?),
+					3 => Self::V3(self.try_into()?),
+					4 => Self::V4(self.try_into()?),
+					_ => return Err(()),
+				})
+			}
+		}
+	};
 	($(#[$attr:meta])* pub enum $n:ident {
 		$(#[$index3:meta])+
 		V3($v3:ty),
@@ -181,7 +211,7 @@ macro_rules! versioned_type {
 		}
 	};
 
-	($(#[$attr:meta])* pub enum $n:ident {
+	($(#[$attr:meta])* pub enum $n:ident $(<$($gen:ident),*>)?{
 		$(#[$index2:meta])+
 		V2($v2:ty),
 		$(#[$index3:meta])+
@@ -198,68 +228,59 @@ macro_rules! versioned_type {
 		)]
 		#[codec(encode_bound())]
 		#[codec(decode_bound())]
+        $(#[scale_info(bounds(), skip_type_params($($gen)+))])?
 		#[scale_info(replace_segment("staging_xcm", "xcm"))]
 		$(#[$attr])*
-		pub enum $n {
+		pub enum $n<$($($gen),*)?>{
 			$(#[$index2])*
 			V2($v2),
 			$(#[$index3])*
 			V3($v3),
 			$(#[$index4])*
 			V4($v4),
 		}
-		impl $n {
+		impl<$($($gen),*)?> $n<$($($gen),*)?> {
 			pub fn try_as<T>(&self) -> Result<&T, ()> where Self: TryAs<T> {
 				<Self as TryAs<T>>::try_as(&self)
 			}
 		}
-		impl TryAs<$v2> for $n {
+		impl<$($($gen),*)?> TryAs<$v2> for $n <$($($gen),*)?>{
 			fn try_as(&self) -> Result<&$v2, ()> {
 				match &self {
 					Self::V2(ref x) => Ok(x),
 					_ => Err(()),
 				}
 			}
 		}
-		impl TryAs<$v3> for $n {
+		impl<$($($gen),*)?> TryAs<$v3> for $n <$($($gen),*)?>{
 			fn try_as(&self) -> Result<&$v3, ()> {
 				match &self {
 					Self::V3(ref x) => Ok(x),
 					_ => Err(()),
 				}
 			}
 		}
-		impl TryAs<$v4> for $n {
+		impl<$($($gen),*)?> TryAs<$v4> for $n<$($($gen),*)?> {
 			fn try_as(&self) -> Result<&$v4, ()> {
 				match &self {
 					Self::V4(ref x) => Ok(x),
 					_ => Err(()),
 				}
 			}
 		}
-		impl IntoVersion for $n {
-			fn into_version(self, n: Version) -> Result<Self, ()> {
-				Ok(match n {
-					1 | 2 => Self::V2(self.try_into()?),
-					3 => Self::V3(self.try_into()?),
-					4 => Self::V4(self.try_into()?),
-					_ => return Err(()),
-				})
-			}
-		}
-		impl From<$v2> for $n {
+		impl<$($($gen),*)?> From<$v2> for $n<$($($gen),*)?> {
 			fn from(x: $v2) -> Self {
 				$n::V2(x)
 			}
 		}
-		impl<T: Into<$v4>> From<T> for $n {
+		impl<$($($gen,),+)? T: Into<$v4>> From<T> for $n<$($($gen),*)?> {
 			fn from(x: T) -> Self {
 				$n::V4(x.into())
 			}
 		}
-		impl TryFrom<$n> for $v2 {
+		impl<$($($gen),*)?>TryFrom<$n<$($($gen),*)?>> for $v2 {
 			type Error = ();
-			fn try_from(x: $n) -> Result<Self, ()> {
+			fn try_from(x: $n<$($($gen),*)?>) -> Result<Self, ()> {
 				use $n::*;
 				match x {
 					V2(x) => Ok(x),
@@ -271,9 +292,9 @@ macro_rules! versioned_type {
 				}
 			}
 		}
-		impl TryFrom<$n> for $v3 {
+		impl<$($($gen),*)?> TryFrom<$n<$($($gen),*)?>> for $v3 {
 			type Error = ();
-			fn try_from(x: $n) -> Result<Self, ()> {
+			fn try_from(x: $n <$($($gen),*)?>) -> Result<Self, ()> {
 				use $n::*;
 				match x {
 					V2(x) => x.try_into(),
@@ -282,9 +303,9 @@ macro_rules! versioned_type {
 				}
 			}
 		}
-		impl TryFrom<$n> for $v4 {
+		impl<$($($gen),*)?> TryFrom<$n <$($($gen),*)?>> for $v4 {
 			type Error = ();
-			fn try_from(x: $n) -> Result<Self, ()> {
+			fn try_from(x: $n<$($($gen),*)?>) -> Result<Self, ()> {
 				use $n::*;
 				match x {
 					V2(x) => {
@@ -296,12 +317,10 @@ macro_rules! versioned_type {
 				}
 			}
 		}
-		impl MaxEncodedLen for $n {
-			fn max_encoded_len() -> usize {
-				<$v3>::max_encoded_len()
-			}
-		}
-		impl IdentifyVersion for $n {
+		// internal macro that handles some edge cases
+		versioned_type!(@internal $n, $v3, $v4, $($($gen),+)?);
+
+		impl<$($($gen),*)?> IdentifyVersion for $n<$($($gen),*)?>{
 			fn identify_version(&self) -> Version {
 				use $n::*;
 				match self {
@@ -421,41 +440,15 @@ versioned_type! {
 #[deprecated(note = "Use `VersionedAssets` instead")]
 pub type VersionedMultiAssets = VersionedAssets;
 
-/// A single XCM message, together with its version code.
-#[derive(Derivative, Encode, Decode, TypeInfo)]
-#[derivative(Clone(bound = ""), Eq(bound = ""), PartialEq(bound = ""), Debug(bound = ""))]
-#[codec(encode_bound())]
-#[codec(decode_bound())]
-#[scale_info(bounds(), skip_type_params(RuntimeCall))]
-#[scale_info(replace_segment("staging_xcm", "xcm"))]
-pub enum VersionedXcm<RuntimeCall> {
-	#[codec(index = 2)]
-	#[deprecated]
-	V2(v2::Xcm<RuntimeCall>),
-	#[codec(index = 3)]
-	V3(v3::Xcm<RuntimeCall>),
-	#[codec(index = 4)]
-	V4(v4::Xcm<RuntimeCall>),
-}
 
-impl<C> IntoVersion for VersionedXcm<C> {
-	fn into_version(self, n: Version) -> Result<Self, ()> {
-		Ok(match n {
-			2 => Self::V2(self.try_into()?),
-			3 => Self::V3(self.try_into()?),
-			4 => Self::V4(self.try_into()?),
-			_ => return Err(()),
-		})
-	}
-}
-
-impl<C> IdentifyVersion for VersionedXcm<C> {
-	fn identify_version(&self) -> Version {
-		match self {
-			Self::V2(_) => v2::VERSION,
-			Self::V3(_) => v3::VERSION,
-			Self::V4(_) => v4::VERSION,
-		}
+versioned_type! {
+	pub enum VersionedXcm<RuntimeCall> {
+		#[codec(index = 2)]
+		V2(v2::Xcm<RuntimeCall>),
+		#[codec(index = 3)]
+		V3(v3::Xcm<RuntimeCall>),
+		#[codec(index = 4)]
+		V4(v4::Xcm<RuntimeCall>),
 	}
 }
 
@@ -476,66 +469,6 @@ impl<C> VersionedXcm<C> {
 	}
 }
 
-impl<RuntimeCall> From<v2::Xcm<RuntimeCall>> for VersionedXcm<RuntimeCall> {
-	fn from(x: v2::Xcm<RuntimeCall>) -> Self {
-		VersionedXcm::V2(x)
-	}
-}
-
-impl<RuntimeCall> From<v3::Xcm<RuntimeCall>> for VersionedXcm<RuntimeCall> {
-	fn from(x: v3::Xcm<RuntimeCall>) -> Self {
-		VersionedXcm::V3(x)
-	}
-}
-
-impl<RuntimeCall> From<v4::Xcm<RuntimeCall>> for VersionedXcm<RuntimeCall> {
-	fn from(x: v4::Xcm<RuntimeCall>) -> Self {
-		VersionedXcm::V4(x)
-	}
-}
-
-impl<RuntimeCall> TryFrom<VersionedXcm<RuntimeCall>> for v2::Xcm<RuntimeCall> {
-	type Error = ();
-	fn try_from(x: VersionedXcm<RuntimeCall>) -> Result<Self, ()> {
-		use VersionedXcm::*;
-		match x {
-			V2(x) => Ok(x),
-			V3(x) => x.try_into(),
-			V4(x) => {
-				let v3: v3::Xcm<RuntimeCall> = x.try_into()?;
-				v3.try_into()
-			},
-		}
-	}
-}
-
-impl<Call> TryFrom<VersionedXcm<Call>> for v3::Xcm<Call> {
-	type Error = ();
-	fn try_from(x: VersionedXcm<Call>) -> Result<Self, ()> {
-		use VersionedXcm::*;
-		match x {
-			V2(x) => x.try_into(),
-			V3(x) => Ok(x),
-			V4(x) => x.try_into(),
-		}
-	}
-}
-
-impl<Call> TryFrom<VersionedXcm<Call>> for v4::Xcm<Call> {
-	type Error = ();
-	fn try_from(x: VersionedXcm<Call>) -> Result<Self, ()> {
-		use VersionedXcm::*;
-		match x {
-			V2(x) => {
-				let v3: v3::Xcm<Call> = x.try_into()?;
-				v3.try_into()
-			},
-			V3(x) => x.try_into(),
-			V4(x) => Ok(x),
-		}
-	}
-}
-
 /// Convert an `Xcm` datum into a `VersionedXcm`, based on a destination `Location` which will
 /// interpret it.
 pub trait WrapVersion {

prdoc/pr_4378.prdoc

@@ -0,0 +1,15 @@
+# Schema: Polkadot SDK PRDoc Schema (prdoc) v1.0.0
+# See doc at https://raw.githubusercontent.com/paritytech/polkadot-sdk/master/prdoc/schema_user.json
+
+title: "Use `versioned_type!` macro for `VersionedXcm`"
+
+doc:
+  - audience: Runtime Dev
+    description: |
+      Currently, all other versioned types in the `staging-xcm` are created using `versioned_type!` macro, except for `VersionedXcm`. 
+      This PR changes `versioned_type` macro so that it can be used for `VersionedXcm` as well. This is done by adding optional
+      generic type param to an enum that is passed to the macro.
+
+crates:
+  - name: staging-xcm
+    bump: patch