remove OnStakerSlash replace with OnStakingEvents (#14527)

* remove 'OnStakerSlash', replace with 'OnStakingEvents'

* fix other features in pallets

* small fixes

* fix docs

* fix docs

* fix docs

* Update primitives/staking/src/lib.rs

Co-authored-by: Gonçalo Pestana <g6pestana@gmail.com>

---------

Co-authored-by: Gonçalo Pestana <g6pestana@gmail.com>

substrate/frame/babe/src/mock.rs

@@ -182,7 +182,7 @@ impl onchain::Config for OnChainSeqPhragmen {
 impl pallet_staking::Config for Test {
 	type MaxNominations = ConstU32<16>;
 	type RewardRemainder = ();
-	type CurrencyToVote = frame_support::traits::SaturatingCurrencyToVote;
+	type CurrencyToVote = ();
 	type RuntimeEvent = RuntimeEvent;
 	type Currency = Balances;
 	type CurrencyBalance = <Self as pallet_balances::Config>::Balance;
@@ -204,7 +204,7 @@ impl pallet_staking::Config for Test {
 	type TargetList = pallet_staking::UseValidatorsMap<Self>;
 	type MaxUnlockingChunks = ConstU32<32>;
 	type HistoryDepth = ConstU32<84>;
-	type OnStakerSlash = ();
+	type EventListeners = ();
 	type BenchmarkingConfig = pallet_staking::TestBenchmarkingConfig;
 	type WeightInfo = ();
 }

substrate/frame/beefy/src/mock.rs

@@ -206,7 +206,7 @@ impl onchain::Config for OnChainSeqPhragmen {
 impl pallet_staking::Config for Test {
 	type MaxNominations = ConstU32<16>;
 	type RewardRemainder = ();
-	type CurrencyToVote = frame_support::traits::SaturatingCurrencyToVote;
+	type CurrencyToVote = ();
 	type RuntimeEvent = RuntimeEvent;
 	type Currency = Balances;
 	type CurrencyBalance = <Self as pallet_balances::Config>::Balance;
@@ -228,7 +228,7 @@ impl pallet_staking::Config for Test {
 	type TargetList = pallet_staking::UseValidatorsMap<Self>;
 	type MaxUnlockingChunks = ConstU32<32>;
 	type HistoryDepth = ConstU32<84>;
-	type OnStakerSlash = ();
+	type EventListeners = ();
 	type BenchmarkingConfig = pallet_staking::TestBenchmarkingConfig;
 	type WeightInfo = ();
 }

substrate/frame/election-provider-multi-phase/test-staking-e2e/src/mock.rs

@@ -265,7 +265,7 @@ impl pallet_staking::Config for Runtime {
 	type Currency = Balances;
 	type CurrencyBalance = Balance;
 	type UnixTime = Timestamp;
-	type CurrencyToVote = traits::SaturatingCurrencyToVote;
+	type CurrencyToVote = ();
 	type RewardRemainder = ();
 	type RuntimeEvent = RuntimeEvent;
 	type Slash = (); // burn slashes
@@ -285,7 +285,7 @@ impl pallet_staking::Config for Runtime {
 	type TargetList = pallet_staking::UseValidatorsMap<Self>;
 	type MaxUnlockingChunks = ConstU32<32>;
 	type HistoryDepth = HistoryDepth;
-	type OnStakerSlash = ();
+	type EventListeners = ();
 	type WeightInfo = pallet_staking::weights::SubstrateWeight<Runtime>;
 	type BenchmarkingConfig = pallet_staking::TestBenchmarkingConfig;
 }

substrate/frame/elections-phragmen/Cargo.toml

@@ -26,6 +26,7 @@ sp-io = { version = "23.0.0", default-features = false, path = "../../primitives
 sp-npos-elections = { version = "4.0.0-dev", default-features = false, path = "../../primitives/npos-elections" }
 sp-runtime = { version = "24.0.0", default-features = false, path = "../../primitives/runtime" }
 sp-std = { version = "8.0.0", default-features = false, path = "../../primitives/std" }
+sp-staking = { default-features = false, path = "../../primitives/staking" }
 
 [dev-dependencies]
 pallet-balances = { version = "4.0.0-dev", path = "../balances" }

substrate/frame/elections-phragmen/src/lib.rs

@@ -101,9 +101,9 @@
 use codec::{Decode, Encode};
 use frame_support::{
 	traits::{
-		defensive_prelude::*, ChangeMembers, Contains, ContainsLengthBound, Currency,
-		CurrencyToVote, Get, InitializeMembers, LockIdentifier, LockableCurrency, OnUnbalanced,
-		ReservableCurrency, SortedMembers, WithdrawReasons,
+		defensive_prelude::*, ChangeMembers, Contains, ContainsLengthBound, Currency, Get,
+		InitializeMembers, LockIdentifier, LockableCurrency, OnUnbalanced, ReservableCurrency,
+		SortedMembers, WithdrawReasons,
 	},
 	weights::Weight,
 };
@@ -113,6 +113,7 @@ use sp_runtime::{
 	traits::{Saturating, StaticLookup, Zero},
 	DispatchError, Perbill, RuntimeDebug,
 };
+use sp_staking::currency_to_vote::CurrencyToVote;
 use sp_std::{cmp::Ordering, prelude::*};
 
 #[cfg(any(feature = "try-runtime", test))]
@@ -1424,7 +1425,7 @@ mod tests {
 		type PalletId = ElectionsPhragmenPalletId;
 		type RuntimeEvent = RuntimeEvent;
 		type Currency = Balances;
-		type CurrencyToVote = frame_support::traits::SaturatingCurrencyToVote;
+		type CurrencyToVote = ();
 		type ChangeMembers = TestChangeMembers;
 		type InitializeMembers = ();
 		type CandidacyBond = CandidacyBond;

substrate/frame/fast-unstake/src/mock.rs

@@ -137,7 +137,7 @@ impl pallet_staking::Config for Runtime {
 	type Currency = Balances;
 	type CurrencyBalance = Balance;
 	type UnixTime = pallet_timestamp::Pallet<Self>;
-	type CurrencyToVote = frame_support::traits::SaturatingCurrencyToVote;
+	type CurrencyToVote = ();
 	type RewardRemainder = ();
 	type RuntimeEvent = RuntimeEvent;
 	type Slash = ();
@@ -157,7 +157,7 @@ impl pallet_staking::Config for Runtime {
 	type VoterList = pallet_staking::UseNominatorsAndValidatorsMap<Self>;
 	type TargetList = pallet_staking::UseValidatorsMap<Self>;
 	type MaxUnlockingChunks = ConstU32<32>;
-	type OnStakerSlash = ();
+	type EventListeners = ();
 	type BenchmarkingConfig = pallet_staking::TestBenchmarkingConfig;
 	type WeightInfo = ();
 }

substrate/frame/grandpa/src/mock.rs

@@ -187,7 +187,7 @@ impl onchain::Config for OnChainSeqPhragmen {
 impl pallet_staking::Config for Test {
 	type MaxNominations = ConstU32<16>;
 	type RewardRemainder = ();
-	type CurrencyToVote = frame_support::traits::SaturatingCurrencyToVote;
+	type CurrencyToVote = ();
 	type RuntimeEvent = RuntimeEvent;
 	type Currency = Balances;
 	type CurrencyBalance = <Self as pallet_balances::Config>::Balance;
@@ -209,7 +209,7 @@ impl pallet_staking::Config for Test {
 	type TargetList = pallet_staking::UseValidatorsMap<Self>;
 	type MaxUnlockingChunks = ConstU32<32>;
 	type HistoryDepth = ConstU32<84>;
-	type OnStakerSlash = ();
+	type EventListeners = ();
 	type BenchmarkingConfig = pallet_staking::TestBenchmarkingConfig;
 	type WeightInfo = ();
 }

substrate/frame/nomination-pools/benchmarking/src/mock.rs

@@ -99,7 +99,7 @@ impl pallet_staking::Config for Runtime {
 	type Currency = Balances;
 	type CurrencyBalance = Balance;
 	type UnixTime = pallet_timestamp::Pallet<Self>;
-	type CurrencyToVote = frame_support::traits::SaturatingCurrencyToVote;
+	type CurrencyToVote = ();
 	type RewardRemainder = ();
 	type RuntimeEvent = RuntimeEvent;
 	type Slash = ();
@@ -120,7 +120,7 @@ impl pallet_staking::Config for Runtime {
 	type TargetList = pallet_staking::UseValidatorsMap<Self>;
 	type MaxUnlockingChunks = ConstU32<32>;
 	type HistoryDepth = ConstU32<84>;
-	type OnStakerSlash = Pools;
+	type EventListeners = Pools;
 	type BenchmarkingConfig = pallet_staking::TestBenchmarkingConfig;
 	type WeightInfo = ();
 }

substrate/frame/nomination-pools/src/lib.rs

@@ -326,7 +326,7 @@
 //!
 //! This section assumes that the slash computation is executed by
 //! `pallet_staking::StakingLedger::slash`, which passes the information to this pallet via
-//! [`sp_staking::OnStakerSlash::on_slash`].
+//! [`sp_staking::OnStakingUpdate::on_slash`].
 //!
 //! Unbonding pools need to be slashed to ensure all nominators whom where in the bonded pool while
 //! it was backing a validator that equivocated are punished. Without these measures a member could
@@ -341,10 +341,6 @@
 //! in addition to the unbonding pools. For maintenance simplicity these are not implemented.
 //! Related: <https://github.com/paritytech/substrate/issues/10860>
 //!
-//! **Relevant methods:**
-//!
-//! * [`Pallet::on_slash`]
-//!
 //! ### Limitations
 //!
 //! * PoolMembers cannot vote with their staked funds because they are transferred into the pools
@@ -375,7 +371,7 @@ use sp_runtime::{
 	},
 	FixedPointNumber, Perbill,
 };
-use sp_staking::{EraIndex, OnStakerSlash, StakingInterface};
+use sp_staking::{EraIndex, StakingInterface};
 use sp_std::{collections::btree_map::BTreeMap, fmt::Debug, ops::Div, vec::Vec};
 
 #[cfg(any(feature = "try-runtime", feature = "fuzzing", test, debug_assertions))]
@@ -3265,7 +3261,7 @@ impl<T: Config> Pallet<T> {
 	}
 }
 
-impl<T: Config> OnStakerSlash<T::AccountId, BalanceOf<T>> for Pallet<T> {
+impl<T: Config> sp_staking::OnStakingUpdate<T::AccountId, BalanceOf<T>> for Pallet<T> {
 	fn on_slash(
 		pool_account: &T::AccountId,
 		// Bonded balance is always read directly from staking, therefore we don't need to update

substrate/frame/nomination-pools/src/mock.rs

@@ -47,6 +47,7 @@ impl StakingMock {
 impl sp_staking::StakingInterface for StakingMock {
 	type Balance = Balance;
 	type AccountId = AccountId;
+	type CurrencyToVote = ();
 
 	fn minimum_nominator_bond() -> Self::Balance {
 		StakingMinBond::get()

substrate/frame/nomination-pools/test-staking/src/mock.rs

@@ -113,7 +113,7 @@ impl pallet_staking::Config for Runtime {
 	type Currency = Balances;
 	type CurrencyBalance = Balance;
 	type UnixTime = pallet_timestamp::Pallet<Self>;
-	type CurrencyToVote = frame_support::traits::SaturatingCurrencyToVote;
+	type CurrencyToVote = ();
 	type RewardRemainder = ();
 	type RuntimeEvent = RuntimeEvent;
 	type Slash = ();
@@ -134,7 +134,7 @@ impl pallet_staking::Config for Runtime {
 	type TargetList = pallet_staking::UseValidatorsMap<Self>;
 	type MaxUnlockingChunks = ConstU32<32>;
 	type HistoryDepth = ConstU32<84>;
-	type OnStakerSlash = Pools;
+	type EventListeners = Pools;
 	type BenchmarkingConfig = pallet_staking::TestBenchmarkingConfig;
 	type WeightInfo = ();
 }

substrate/frame/offences/benchmarking/src/mock.rs

@@ -162,7 +162,7 @@ impl pallet_staking::Config for Test {
 	type Currency = Balances;
 	type CurrencyBalance = <Self as pallet_balances::Config>::Balance;
 	type UnixTime = pallet_timestamp::Pallet<Self>;
-	type CurrencyToVote = frame_support::traits::SaturatingCurrencyToVote;
+	type CurrencyToVote = ();
 	type RewardRemainder = ();
 	type RuntimeEvent = RuntimeEvent;
 	type Slash = ();
@@ -182,7 +182,7 @@ impl pallet_staking::Config for Test {
 	type TargetList = pallet_staking::UseValidatorsMap<Self>;
 	type MaxUnlockingChunks = ConstU32<32>;
 	type HistoryDepth = ConstU32<84>;
-	type OnStakerSlash = ();
+	type EventListeners = ();
 	type BenchmarkingConfig = pallet_staking::TestBenchmarkingConfig;
 	type WeightInfo = ();
 }

substrate/frame/root-offences/src/mock.rs

@@ -149,17 +149,6 @@ impl onchain::Config for OnChainSeqPhragmen {
 	type TargetsBound = ConstU32<{ u32::MAX }>;
 }
 
-pub struct OnStakerSlashMock<T: Config>(core::marker::PhantomData<T>);
-impl<T: Config> sp_staking::OnStakerSlash<AccountId, Balance> for OnStakerSlashMock<T> {
-	fn on_slash(
-		_pool_account: &AccountId,
-		slashed_bonded: Balance,
-		slashed_chunks: &BTreeMap<EraIndex, Balance>,
-	) {
-		LedgerSlashPerEra::set((slashed_bonded, slashed_chunks.clone()));
-	}
-}
-
 parameter_types! {
 	pub const RewardCurve: &'static PiecewiseLinear<'static> = &REWARD_CURVE;
 	pub static Offset: BlockNumber = 0;
@@ -176,7 +165,7 @@ impl pallet_staking::Config for Test {
 	type Currency = Balances;
 	type CurrencyBalance = <Self as pallet_balances::Config>::Balance;
 	type UnixTime = Timestamp;
-	type CurrencyToVote = frame_support::traits::SaturatingCurrencyToVote;
+	type CurrencyToVote = ();
 	type RewardRemainder = ();
 	type RuntimeEvent = RuntimeEvent;
 	type Slash = ();
@@ -196,7 +185,7 @@ impl pallet_staking::Config for Test {
 	type MaxUnlockingChunks = ConstU32<32>;
 	type HistoryDepth = ConstU32<84>;
 	type VoterList = pallet_staking::UseNominatorsAndValidatorsMap<Self>;
-	type OnStakerSlash = OnStakerSlashMock<Test>;
+	type EventListeners = ();
 	type BenchmarkingConfig = pallet_staking::TestBenchmarkingConfig;
 	type WeightInfo = ();
 }

substrate/frame/session/benchmarking/src/mock.rs

@@ -164,7 +164,7 @@ impl pallet_staking::Config for Test {
 	type Currency = Balances;
 	type CurrencyBalance = <Self as pallet_balances::Config>::Balance;
 	type UnixTime = pallet_timestamp::Pallet<Self>;
-	type CurrencyToVote = frame_support::traits::SaturatingCurrencyToVote;
+	type CurrencyToVote = ();
 	type RewardRemainder = ();
 	type RuntimeEvent = RuntimeEvent;
 	type Slash = ();
@@ -184,7 +184,7 @@ impl pallet_staking::Config for Test {
 	type HistoryDepth = ConstU32<84>;
 	type VoterList = pallet_staking::UseNominatorsAndValidatorsMap<Self>;
 	type TargetList = pallet_staking::UseValidatorsMap<Self>;
-	type OnStakerSlash = ();
+	type EventListeners = ();
 	type BenchmarkingConfig = pallet_staking::TestBenchmarkingConfig;
 	type WeightInfo = ();
 }

substrate/frame/staking/src/benchmarking.rs

@@ -26,13 +26,13 @@ use frame_election_provider_support::SortedListProvider;
 use frame_support::{
 	dispatch::UnfilteredDispatchable,
 	pallet_prelude::*,
-	traits::{Currency, CurrencyToVote, Get, Imbalance},
+	traits::{Currency, Get, Imbalance},
 };
 use sp_runtime::{
 	traits::{Bounded, One, StaticLookup, TrailingZeroInput, Zero},
 	Perbill, Percent,
 };
-use sp_staking::SessionIndex;
+use sp_staking::{currency_to_vote::CurrencyToVote, SessionIndex};
 use sp_std::prelude::*;
 
 pub use frame_benchmarking::v1::{

substrate/frame/staking/src/lib.rs

@@ -314,7 +314,7 @@ use sp_runtime::{
 pub use sp_staking::StakerStatus;
 use sp_staking::{
 	offence::{Offence, OffenceError, ReportOffence},
-	EraIndex, SessionIndex,
+	EraIndex, OnStakingUpdate, SessionIndex,
 };
 use sp_std::{collections::btree_map::BTreeMap, prelude::*};
 pub use weights::WeightInfo;
@@ -549,7 +549,7 @@ impl<T: Config> StakingLedger<T> {
 	///
 	/// `slash_era` is the era in which the slash (which is being enacted now) actually happened.
 	///
-	/// This calls `Config::OnStakerSlash::on_slash` with information as to how the slash was
+	/// This calls `Config::OnStakingUpdate::on_slash` with information as to how the slash was
 	/// applied.
 	pub fn slash(
 		&mut self,
@@ -562,7 +562,6 @@ impl<T: Config> StakingLedger<T> {
 		}
 
 		use sp_runtime::PerThing as _;
-		use sp_staking::OnStakerSlash as _;
 		let mut remaining_slash = slash_amount;
 		let pre_slash_total = self.total;
 
@@ -667,7 +666,7 @@ impl<T: Config> StakingLedger<T> {
 		// clean unlocking chunks that are set to zero.
 		self.unlocking.retain(|c| !c.value.is_zero());
 
-		T::OnStakerSlash::on_slash(&self.stash, self.active, &slashed_unlocking);
+		T::EventListeners::on_slash(&self.stash, self.active, &slashed_unlocking);
 		pre_slash_total.saturating_sub(self.total)
 	}
 }

substrate/frame/staking/src/mock.rs

@@ -236,7 +236,6 @@ parameter_types! {
 	pub static HistoryDepth: u32 = 80;
 	pub static MaxUnlockingChunks: u32 = 32;
 	pub static RewardOnUnbalanceWasCalled: bool = false;
-	pub static LedgerSlashPerEra: (BalanceOf<Test>, BTreeMap<EraIndex, BalanceOf<Test>>) = (Zero::zero(), BTreeMap::new());
 	pub static MaxWinners: u32 = 100;
 }
 
@@ -268,8 +267,14 @@ impl OnUnbalanced<PositiveImbalanceOf<Test>> for MockReward {
 	}
 }
 
-pub struct OnStakerSlashMock<T: Config>(core::marker::PhantomData<T>);
-impl<T: Config> sp_staking::OnStakerSlash<AccountId, Balance> for OnStakerSlashMock<T> {
+parameter_types! {
+	pub static LedgerSlashPerEra:
+		(BalanceOf<Test>, BTreeMap<EraIndex, BalanceOf<Test>>) =
+		(Zero::zero(), BTreeMap::new());
+}
+
+pub struct EventListenerMock;
+impl OnStakingUpdate<AccountId, Balance> for EventListenerMock {
 	fn on_slash(
 		_pool_account: &AccountId,
 		slashed_bonded: Balance,
@@ -284,7 +289,7 @@ impl crate::pallet::pallet::Config for Test {
 	type Currency = Balances;
 	type CurrencyBalance = <Self as pallet_balances::Config>::Balance;
 	type UnixTime = Timestamp;
-	type CurrencyToVote = frame_support::traits::SaturatingCurrencyToVote;
+	type CurrencyToVote = ();
 	type RewardRemainder = RewardRemainderMock;
 	type RuntimeEvent = RuntimeEvent;
 	type Slash = ();
@@ -305,7 +310,7 @@ impl crate::pallet::pallet::Config for Test {
 	type TargetList = UseValidatorsMap<Self>;
 	type MaxUnlockingChunks = MaxUnlockingChunks;
 	type HistoryDepth = HistoryDepth;
-	type OnStakerSlash = OnStakerSlashMock<Test>;
+	type EventListeners = EventListenerMock;
 	type BenchmarkingConfig = TestBenchmarkingConfig;
 	type WeightInfo = ();
 }

substrate/frame/staking/src/pallet/impls.rs

@@ -26,8 +26,8 @@ use frame_support::{
 	dispatch::WithPostDispatchInfo,
 	pallet_prelude::*,
 	traits::{
-		Currency, CurrencyToVote, Defensive, DefensiveResult, EstimateNextNewSession, Get,
-		Imbalance, LockableCurrency, OnUnbalanced, TryCollect, UnixTime, WithdrawReasons,
+		Currency, Defensive, DefensiveResult, EstimateNextNewSession, Get, Imbalance,
+		LockableCurrency, OnUnbalanced, TryCollect, UnixTime, WithdrawReasons,
 	},
 	weights::Weight,
 };
@@ -38,6 +38,7 @@ use sp_runtime::{
 	Perbill,
 };
 use sp_staking::{
+	currency_to_vote::CurrencyToVote,
 	offence::{DisableStrategy, OffenceDetails, OnOffenceHandler},
 	EraIndex, SessionIndex, Stake, StakingInterface,
 };
@@ -1568,10 +1569,10 @@ impl<T: Config> SortedListProvider<T::AccountId> for UseNominatorsAndValidatorsM
 	}
 }
 
-// NOTE: in this entire impl block, the assumption is that `who` is a stash account.
 impl<T: Config> StakingInterface for Pallet<T> {
 	type AccountId = T::AccountId;
 	type Balance = BalanceOf<T>;
+	type CurrencyToVote = T::CurrencyToVote;
 
 	fn minimum_nominator_bond() -> Self::Balance {
 		MinNominatorBond::<T>::get()

substrate/frame/staking/src/pallet/mod.rs

@@ -24,7 +24,7 @@ use frame_support::{
 	dispatch::Codec,
 	pallet_prelude::*,
 	traits::{
-		Currency, CurrencyToVote, Defensive, DefensiveResult, DefensiveSaturating, EnsureOrigin,
+		Currency, Defensive, DefensiveResult, DefensiveSaturating, EnsureOrigin,
 		EstimateNextNewSession, Get, LockIdentifier, LockableCurrency, OnUnbalanced, TryCollect,
 		UnixTime,
 	},
@@ -113,7 +113,7 @@ pub mod pallet {
 		/// in 128.
 		/// Consequently, the backward convert is used convert the u128s from sp-elections back to a
 		/// [`BalanceOf`].
-		type CurrencyToVote: CurrencyToVote<BalanceOf<Self>>;
+		type CurrencyToVote: sp_staking::currency_to_vote::CurrencyToVote<BalanceOf<Self>>;
 
 		/// Something that provides the election functionality.
 		type ElectionProvider: ElectionProvider<
@@ -261,9 +261,11 @@ pub mod pallet {
 		#[pallet::constant]
 		type MaxUnlockingChunks: Get<u32>;
 
-		/// A hook called when any staker is slashed. Mostly likely this can be a no-op unless
-		/// other pallets exist that are affected by slashing per-staker.
-		type OnStakerSlash: sp_staking::OnStakerSlash<Self::AccountId, BalanceOf<Self>>;
+		/// Something that listens to staking updates and performs actions based on the data it
+		/// receives.
+		///
+		/// WARNING: this only reports slashing events for the time being.
+		type EventListeners: sp_staking::OnStakingUpdate<Self::AccountId, BalanceOf<Self>>;
 
 		/// Some parameters of the benchmarking.
 		type BenchmarkingConfig: BenchmarkingConfig;

substrate/frame/support/src/traits.rs

@@ -102,10 +102,7 @@ pub use dispatch::{
 };
 
 mod voting;
-pub use voting::{
-	ClassCountOf, CurrencyToVote, PollStatus, Polling, SaturatingCurrencyToVote,
-	U128CurrencyToVote, VoteTally,
-};
+pub use voting::{ClassCountOf, PollStatus, Polling, VoteTally};
 
 mod preimages;
 pub use preimages::{Bounded, BoundedInline, FetchResult, Hash, QueryPreimage, StorePreimage};

substrate/frame/support/src/traits/voting.rs

@@ -20,81 +20,10 @@
 
 use crate::dispatch::{DispatchError, Parameter};
 use codec::{HasCompact, MaxEncodedLen};
-use sp_arithmetic::{
-	traits::{SaturatedConversion, UniqueSaturatedFrom, UniqueSaturatedInto},
-	Perbill,
-};
+use sp_arithmetic::Perbill;
 use sp_runtime::traits::Member;
 use sp_std::prelude::*;
 
-/// A trait similar to `Convert` to convert values from `B` an abstract balance type
-/// into u64 and back from u128. (This conversion is used in election and other places where complex
-/// calculation over balance type is needed)
-///
-/// Total issuance of the currency is passed in, but an implementation of this trait may or may not
-/// use it.
-///
-/// # WARNING
-///
-/// the total issuance being passed in implies that the implementation must be aware of the fact
-/// that its values can affect the outcome. This implies that if the vote value is dependent on the
-/// total issuance, it should never ber written to storage for later re-use.
-pub trait CurrencyToVote<B> {
-	/// Convert balance to u64.
-	fn to_vote(value: B, issuance: B) -> u64;
-
-	/// Convert u128 to balance.
-	fn to_currency(value: u128, issuance: B) -> B;
-}
-
-/// An implementation of `CurrencyToVote` tailored for chain's that have a balance type of u128.
-///
-/// The factor is the `(total_issuance / u64::MAX).max(1)`, represented as u64. Let's look at the
-/// important cases:
-///
-/// If the chain's total issuance is less than u64::MAX, this will always be 1, which means that
-/// the factor will not have any effect. In this case, any account's balance is also less. Thus,
-/// both of the conversions are basically an `as`; Any balance can fit in u64.
-///
-/// If the chain's total issuance is more than 2*u64::MAX, then a factor might be multiplied and
-/// divided upon conversion.
-pub struct U128CurrencyToVote;
-
-impl U128CurrencyToVote {
-	fn factor(issuance: u128) -> u128 {
-		(issuance / u64::MAX as u128).max(1)
-	}
-}
-
-impl CurrencyToVote<u128> for U128CurrencyToVote {
-	fn to_vote(value: u128, issuance: u128) -> u64 {
-		(value / Self::factor(issuance)).saturated_into()
-	}
-
-	fn to_currency(value: u128, issuance: u128) -> u128 {
-		value.saturating_mul(Self::factor(issuance))
-	}
-}
-
-/// A naive implementation of `CurrencyConvert` that simply saturates all conversions.
-///
-/// # Warning
-///
-/// This is designed to be used mostly for testing. Use with care, and think about the consequences.
-pub struct SaturatingCurrencyToVote;
-
-impl<B: UniqueSaturatedInto<u64> + UniqueSaturatedFrom<u128>> CurrencyToVote<B>
-	for SaturatingCurrencyToVote
-{
-	fn to_vote(value: B, _: B) -> u64 {
-		value.unique_saturated_into()
-	}
-
-	fn to_currency(value: u128, _: B) -> B {
-		B::unique_saturated_from(value)
-	}
-}
-
 pub trait VoteTally<Votes, Class> {
 	fn new(_: Class) -> Self;
 	fn ayes(&self, class: Class) -> Votes;