Simple implementation of TwoStaticLookup

shawntabrizi · shawntabrizi · commit 20d1a706c9ba · 2020-10-23T21:15:00.000+02:00
diff --git a/bin/node/runtime/src/lib.rs b/bin/node/runtime/src/lib.rs
@@ -53,7 +53,7 @@ use sp_runtime::{
 use sp_runtime::curve::PiecewiseLinear;
 use sp_runtime::transaction_validity::{TransactionValidity, TransactionSource, TransactionPriority};
 use sp_runtime::traits::{
-	self, BlakeTwo256, Block as BlockT, StaticLookup, SaturatedConversion,
+	self, BlakeTwo256, Block as BlockT, StaticLookup, TwoStaticLookup, SaturatedConversion,
 	ConvertInto, OpaqueKeys, NumberFor, Saturating,
 };
 use sp_version::RuntimeVersion;
@@ -169,7 +169,7 @@ impl frame_system::Trait for Runtime {
 	type Hash = Hash;
 	type Hashing = BlakeTwo256;
 	type AccountId = AccountId;
-	type Lookup = NameService;
+	type Lookup = TwoStaticLookup<Indices, NameService>;
 	type Header = generic::Header<BlockNumber, BlakeTwo256>;
 	type Event = Event;
 	type BlockHashCount = BlockHashCount;
diff --git a/primitives/runtime/src/traits.rs b/primitives/runtime/src/traits.rs
@@ -225,6 +225,29 @@ impl<AccountId: Codec + Clone + PartialEq + Debug> StaticLookup for AccountIdLoo
 	}
 }
 
+/// Perform a StaticLookup where there are two lookup sources of the same type.
+pub struct TwoStaticLookup<A, B>(PhantomData<(A, B)>);
+impl<A, B> StaticLookup for TwoStaticLookup<A, B>
+where
+	A: StaticLookup,
+	B: StaticLookup<Source = A::Source, Target = A::Target>,
+{
+	type Source = A::Source;
+	type Target = A::Target;
+
+	fn lookup(x: Self::Source) -> Result<Self::Target, LookupError> {
+		let a = A::lookup(x.clone());
+		if a.is_ok() {
+			return a
+		} else {
+			B::lookup(x)
+		}
+	}
+	fn unlookup(x: Self::Target) -> Self::Source {
+		A::unlookup(x)
+	}
+}
+
 /// Extensible conversion trait. Generic over both source and destination types.
 pub trait Convert<A, B> {
 	/// Make conversion.
