Companion for substrate/pull/6896 (#1610)

* make polkadot work again,

* Fix build

* "Update Substrate"

Co-authored-by: parity-processbot <>

polkadot/runtime/common/src/impls.rs

@@ -16,7 +16,6 @@
 
 //! Auxillary struct/enums for polkadot runtime.
 
-use sp_runtime::traits::Convert;
 use frame_support::traits::{OnUnbalanced, Imbalance, Currency};
 use crate::NegativeImbalance;
 
@@ -41,33 +40,3 @@ where
 		<frame_system::Module<R>>::deposit_event(pallet_balances::RawEvent::Deposit(author, numeric_amount));
 	}
 }
-
-/// Converter for currencies to votes.
-pub struct CurrencyToVoteHandler<R>(sp_std::marker::PhantomData<R>);
-
-impl<R> CurrencyToVoteHandler<R>
-where
-	R: pallet_balances::Trait,
-	R::Balance: Into<u128>,
-{
-	fn factor() -> u128 {
-		let issuance: u128 = <pallet_balances::Module<R>>::total_issuance().into();
-		(issuance / u64::max_value() as u128).max(1)
-	}
-}
-
-impl<R> Convert<u128, u64> for CurrencyToVoteHandler<R>
-where
-	R: pallet_balances::Trait,
-	R::Balance: Into<u128>,
-{
-	fn convert(x: u128) -> u64 { (x / Self::factor()) as u64 }
-}
-
-impl<R> Convert<u128, u128> for CurrencyToVoteHandler<R>
-where
-	R: pallet_balances::Trait,
-	R::Balance: Into<u128>,
-{
-	fn convert(x: u128) -> u128 { x * Self::factor() }
-}

polkadot/runtime/common/src/lib.rs

@@ -45,7 +45,7 @@ pub use pallet_timestamp::Call as TimestampCall;
 pub use pallet_balances::Call as BalancesCall;
 
 /// Implementations of some helper traits passed into runtime modules as associated types.
-pub use impls::{CurrencyToVoteHandler, ToAuthor};
+pub use impls::ToAuthor;
 
 pub type NegativeImbalance<T> = <pallet_balances::Module<T> as Currency<<T as frame_system::Trait>::AccountId>>::NegativeImbalance;
 
@@ -89,6 +89,12 @@ pub type SlowAdjustingFeeUpdate<R> = TargetedFeeAdjustment<
 	MinimumMultiplier
 >;
 
+/// The type used for currency conversion.
+///
+/// This must only be used as long as the balance type is u128.
+pub type CurrencyToVote = frame_support::traits::U128CurrencyToVote;
+static_assertions::assert_eq_size!(primitives::v1::Balance, u128);
+
 /// A placeholder since there is currently no provided session key handler for parachain validator
 /// keys.
 pub struct ParachainSessionKeyPlaceholder<T>(sp_std::marker::PhantomData<T>);

polkadot/runtime/common/src/paras_registrar.rs

@@ -395,7 +395,7 @@ mod tests {
 
 	impl pallet_staking::Trait for Test {
 		type RewardRemainder = ();
-		type CurrencyToVote = ();
+		type CurrencyToVote = frame_support::traits::SaturatingCurrencyToVote;
 		type Event = ();
 		type Currency = pallet_balances::Module<Test>;
 		type Slash = ();