Make ParaId constructible from a const context (#483)

polkadot/parachain/src/lib.rs

@@ -53,7 +53,7 @@ pub mod wasm_api;
 
 use rstd::vec::Vec;
 
-use codec::{Encode, Decode};
+use codec::{Encode, Decode, CompactAs};
 use substrate_primitives::TypeId;
 
 /// Validation parameters for evaluating the parachain validity function.
@@ -79,7 +79,7 @@ pub struct ValidationResult {
 }
 
 /// Unique identifier of a parachain.
-#[derive(PartialEq, Eq, PartialOrd, Ord, Hash, Default, Clone, Copy, Encode, Decode)]
+#[derive(PartialEq, Eq, PartialOrd, Ord, Hash, Default, Clone, Copy, Encode, Decode, CompactAs)]
 #[cfg_attr(feature = "std", derive(serde::Serialize, serde::Deserialize, Debug))]
 pub struct Id(u32);
 
@@ -93,21 +93,6 @@ pub trait ActiveThreads {
 	fn active_threads() -> Vec<Id>;
 }
 
-impl codec::CompactAs for Id {
-	type As = u32;
-	fn encode_as(&self) -> &u32 {
-		&self.0
-	}
-	fn decode_from(x: u32) -> Self {
-		Self(x)
-	}
-}
-impl From<codec::Compact<Id>> for Id {
-	fn from(x: codec::Compact<Id>) -> Id {
-		x.0
-	}
-}
-
 impl From<Id> for u32 {
 	fn from(x: Id) -> Self { x.0 }
 }
@@ -122,15 +107,23 @@ const USER_INDEX_START: u32 = 1000;
 pub const LOWEST_USER_ID: Id = Id(USER_INDEX_START);
 
 impl Id {
-	/// Convert this Id into its inner representation.
+	/// Create an `Id`.
-	pub fn into_inner(self) -> u32 {
+	pub const fn new(id: u32) -> Self {
-		self.0
+		Self(id)
 	}
 
 	/// Returns `true` if this parachain runs with system-level privileges.
 	pub fn is_system(&self) -> bool { self.0 < USER_INDEX_START }
 }
 
+impl rstd::ops::Add<u32> for Id {
+	type Output = Self;
+
+	fn add(self, other: u32) -> Self {
+		Self(self.0 + other)
+	}
+}
+
 // TODO: Remove all of this, move sr-primitives::AccountIdConversion to own crate and and use that.
 // #360
 struct TrailingZeroInput<'a>(&'a [u8]);

polkadot/parachain/src/wasm_api.rs

@@ -60,7 +60,7 @@ pub fn post_message(message: MessageRef) {
 	let data_ptr = message.data.as_ptr();
 	let data_len = message.data.len();
 
-	unsafe { ll::ext_post_message(message.target.into_inner(), data_ptr, data_len as u32) }
+	unsafe { ll::ext_post_message(message.target.into(), data_ptr, data_len as u32) }
 }
 
 /// Post a message to this parachain's relay chain.

polkadot/runtime/src/crowdfund.rs

@@ -610,19 +610,19 @@ mod tests {
 			initial_head_data: Vec<u8>
 		) -> Result<(), &'static str> {
 			PARACHAINS.with(|p| {
-				if p.borrow().contains_key(&id.into_inner()) {
+				if p.borrow().contains_key(&id.into()) {
 					panic!("ID already exists")
 				}
-				p.borrow_mut().insert(id.into_inner(), (code, initial_head_data));
+				p.borrow_mut().insert(id.into(), (code, initial_head_data));
 				Ok(())
 			})
 		}
 		fn deregister_para(id: ParaId) -> Result<(), &'static str> {
 			PARACHAINS.with(|p| {
-				if !p.borrow().contains_key(&id.into_inner()) {
+				if !p.borrow().contains_key(&id.into()) {
 					panic!("ID doesn't exist")
 				}
-				p.borrow_mut().remove(&id.into_inner());
+				p.borrow_mut().remove(&id.into());
 				Ok(())
 			})
 		}

polkadot/runtime/src/registrar.rs

@@ -829,7 +829,7 @@ mod tests {
 	}
 
 	fn user_id(i: u32) -> ParaId {
-		(LOWEST_USER_ID.into_inner() + i).into()
+		LOWEST_USER_ID + i
 	}
 
 	fn attest(id: ParaId, collator: &CollatorPair, head_data: &[u8], block_data: &[u8]) -> AttestedCandidate {

polkadot/runtime/src/slots.rs

@@ -905,19 +905,19 @@ mod tests {
 			initial_head_data: Vec<u8>
 		) -> Result<(), &'static str> {
 			PARACHAINS.with(|p| {
-				if p.borrow().contains_key(&id.into_inner()) {
+				if p.borrow().contains_key(&id.into()) {
 					panic!("ID already exists")
 				}
-				p.borrow_mut().insert(id.into_inner(), (code, initial_head_data));
+				p.borrow_mut().insert(id.into(), (code, initial_head_data));
 				Ok(())
 			})
 		}
 		fn deregister_para(id: ParaId) -> Result<(), &'static str> {
 			PARACHAINS.with(|p| {
-				if !p.borrow().contains_key(&id.into_inner()) {
+				if !p.borrow().contains_key(&id.into()) {
 					panic!("ID doesn't exist")
 				}
-				p.borrow_mut().remove(&id.into_inner());
+				p.borrow_mut().remove(&id.into());
 				Ok(())
 			})
 		}