Relaxed clippy fixes/nits (#2661)

This PR contains just a few clippy fixes and nits, which are, however,
relaxed by workspace clippy settings here:
https://github.com/paritytech/polkadot-sdk/blob/master/Cargo.toml#L483-L506

---------

Co-authored-by: Dmitry Sinyavin <dmitry.sinyavin@parity.io>
Co-authored-by: ordian <write@reusable.software>
Co-authored-by: command-bot <>
Co-authored-by: Bastian Köcher <git@kchr.de>

cumulus/parachain-template/node/src/rpc.rs

@@ -9,7 +9,7 @@ use std::sync::Arc;
 
 use parachain_template_runtime::{opaque::Block, AccountId, Balance, Nonce};
 
-pub use sc_rpc::{DenyUnsafe, SubscriptionTaskExecutor};
+pub use sc_rpc::DenyUnsafe;
 use sc_transaction_pool_api::TransactionPool;
 use sp_api::ProvideRuntimeApi;
 use sp_block_builder::BlockBuilder;

cumulus/parachain-template/runtime/src/weights/mod.rs

@@ -24,5 +24,4 @@ pub mod rocksdb_weights;
 
 pub use block_weights::constants::BlockExecutionWeight;
 pub use extrinsic_weights::constants::ExtrinsicBaseWeight;
-pub use paritydb_weights::constants::ParityDbWeight;
 pub use rocksdb_weights::constants::RocksDbWeight;

cumulus/parachains/runtimes/assets/asset-hub-rococo/src/weights/mod.rs

@@ -42,5 +42,4 @@ pub mod xcm;
 
 pub use block_weights::constants::BlockExecutionWeight;
 pub use extrinsic_weights::constants::ExtrinsicBaseWeight;
-pub use paritydb_weights::constants::ParityDbWeight;
 pub use rocksdb_weights::constants::RocksDbWeight;

cumulus/parachains/runtimes/assets/asset-hub-westend/src/weights/mod.rs

@@ -41,5 +41,4 @@ pub mod xcm;
 
 pub use block_weights::constants::BlockExecutionWeight;
 pub use extrinsic_weights::constants::ExtrinsicBaseWeight;
-pub use paritydb_weights::constants::ParityDbWeight;
 pub use rocksdb_weights::constants::RocksDbWeight;

cumulus/parachains/runtimes/bridge-hubs/bridge-hub-rococo/src/weights/mod.rs

@@ -44,7 +44,6 @@ pub mod xcm;
 
 pub use block_weights::constants::BlockExecutionWeight;
 pub use extrinsic_weights::constants::ExtrinsicBaseWeight;
-pub use paritydb_weights::constants::ParityDbWeight;
 pub use rocksdb_weights::constants::RocksDbWeight;
 
 use crate::Runtime;

cumulus/parachains/runtimes/bridge-hubs/bridge-hub-westend/src/weights/mod.rs

@@ -43,7 +43,6 @@ pub mod xcm;
 
 pub use block_weights::constants::BlockExecutionWeight;
 pub use extrinsic_weights::constants::ExtrinsicBaseWeight;
-pub use paritydb_weights::constants::ParityDbWeight;
 pub use rocksdb_weights::constants::RocksDbWeight;
 
 use crate::Runtime;

cumulus/parachains/runtimes/collectives/collectives-westend/src/weights/mod.rs

@@ -47,5 +47,4 @@ pub mod rocksdb_weights;
 
 pub use block_weights::constants::BlockExecutionWeight;
 pub use extrinsic_weights::constants::ExtrinsicBaseWeight;
-pub use paritydb_weights::constants::ParityDbWeight;
 pub use rocksdb_weights::constants::RocksDbWeight;

cumulus/parachains/runtimes/contracts/contracts-rococo/src/contracts.rs

@@ -26,7 +26,7 @@ use pallet_contracts::{
 };
 use sp_runtime::Perbill;
 
-pub use parachains_common::{rococo::currency::deposit, AVERAGE_ON_INITIALIZE_RATIO};
+pub use parachains_common::rococo::currency::deposit;
 
 // Prints debug output of the `contracts` pallet to stdout if the node is
 // started with `-lruntime::contracts=debug`.

cumulus/parachains/runtimes/contracts/contracts-rococo/src/weights/mod.rs

@@ -24,5 +24,4 @@ pub mod rocksdb_weights;
 
 pub use block_weights::constants::BlockExecutionWeight;
 pub use extrinsic_weights::constants::ExtrinsicBaseWeight;
-pub use paritydb_weights::constants::ParityDbWeight;
 pub use rocksdb_weights::constants::RocksDbWeight;

cumulus/parachains/runtimes/testing/penpal/src/weights/mod.rs

@@ -24,5 +24,4 @@ pub mod rocksdb_weights;
 
 pub use block_weights::constants::BlockExecutionWeight;
 pub use extrinsic_weights::constants::ExtrinsicBaseWeight;
-pub use paritydb_weights::constants::ParityDbWeight;
 pub use rocksdb_weights::constants::RocksDbWeight;

cumulus/polkadot-parachain/src/rpc.rs

@@ -22,7 +22,7 @@ use std::sync::Arc;
 
 use parachains_common::{AccountId, Balance, Block, Nonce};
 use sc_client_api::AuxStore;
-pub use sc_rpc::{DenyUnsafe, SubscriptionTaskExecutor};
+pub use sc_rpc::DenyUnsafe;
 use sc_transaction_pool_api::TransactionPool;
 use sp_api::ProvideRuntimeApi;
 use sp_block_builder::BlockBuilder;

cumulus/polkadot-parachain/src/service.rs

@@ -41,7 +41,7 @@ use sp_core::Pair;
 use jsonrpsee::RpcModule;
 
 use crate::{fake_runtime_api::aura::RuntimeApi, rpc};
-pub use parachains_common::{AccountId, Balance, Block, BlockNumber, Hash, Header, Nonce};
+pub use parachains_common::{AccountId, Balance, Block, Hash, Header, Nonce};
 
 use cumulus_client_consensus_relay_chain::Verifier as RelayChainVerifier;
 use futures::{lock::Mutex, prelude::*};

cumulus/primitives/parachain-inherent/src/lib.rs

@@ -39,8 +39,6 @@ use sp_std::{collections::btree_map::BTreeMap, vec::Vec};
 #[cfg(feature = "std")]
 mod client_side;
 #[cfg(feature = "std")]
-pub use client_side::*;
-#[cfg(feature = "std")]
 mod mock;
 #[cfg(feature = "std")]
 pub use mock::{MockValidationDataInherentDataProvider, MockXcmConfig};

polkadot/node/malus/src/interceptor.rs

@@ -21,7 +21,7 @@
 //! messages on the overseer level.
 
 use polkadot_node_subsystem::*;
-pub use polkadot_node_subsystem::{messages, messages::*, overseer, FromOrchestra};
+pub use polkadot_node_subsystem::{messages::*, overseer, FromOrchestra};
 use std::{future::Future, pin::Pin};
 
 /// Filter incoming and outgoing messages.

polkadot/node/network/bridge/src/rx/mod.rs

@@ -53,11 +53,6 @@ use polkadot_node_subsystem::{
 
 use polkadot_primitives::{AuthorityDiscoveryId, BlockNumber, Hash, ValidatorIndex};
 
-/// Peer set info for network initialization.
-///
-/// To be passed to [`FullNetworkConfiguration::add_notification_protocol`]().
-pub use polkadot_node_network_protocol::peer_set::{peer_sets_info, IsAuthority};
-
 use std::{
 	collections::{hash_map, HashMap},
 	iter::ExactSizeIterator,

polkadot/node/network/bridge/src/tx/mod.rs

@@ -27,10 +27,6 @@ use polkadot_node_subsystem::{
 	overseer, FromOrchestra, OverseerSignal, SpawnedSubsystem,
 };
 
-/// Peer set info for network initialization.
-///
-/// To be passed to [`FullNetworkConfiguration::add_notification_protocol`]().
-pub use polkadot_node_network_protocol::peer_set::{peer_sets_info, IsAuthority};
 use polkadot_node_network_protocol::request_response::Requests;
 use sc_network::{MessageSink, ReputationChange};
 

polkadot/node/service/src/parachains_db/mod.rs

@@ -43,10 +43,7 @@ pub(crate) mod columns {
 
 	// Version 4 only changed structures in approval voting, so we can re-export the v4 definitions.
 	pub mod v3 {
-		pub use super::v4::{
-			COL_APPROVAL_DATA, COL_AVAILABILITY_DATA, COL_AVAILABILITY_META,
-			COL_CHAIN_SELECTION_DATA, COL_DISPUTE_COORDINATOR_DATA, NUM_COLUMNS, ORDERED_COL,
-		};
+		pub use super::v4::{NUM_COLUMNS, ORDERED_COL};
 	}
 
 	pub mod v4 {

polkadot/node/tracking-allocator/src/lib.rs

@@ -226,7 +226,7 @@ unsafe impl<A: GlobalAlloc> GlobalAlloc for TrackingAllocator<A> {
 	}
 
 	#[inline]
-	unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) -> () {
+	unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) {
 		let guard = ALLOCATOR_DATA.lock();
 		TrackingAllocatorData::track_and_check_limits(guard, -(layout.size() as isize));
 		self.0.dealloc(ptr, layout)

polkadot/runtime/common/src/claims.rs

@@ -561,7 +561,7 @@ impl<T: Config> Pallet<T> {
 		}
 
 		// We first need to deposit the balance to ensure that the account exists.
-		CurrencyOf::<T>::deposit_creating(&dest, balance_due);
+		let _ = CurrencyOf::<T>::deposit_creating(&dest, balance_due);
 
 		// Check if this claim should have a vesting schedule.
 		if let Some(vs) = vesting {

polkadot/runtime/parachains/src/assigner_on_demand/mod.rs

@@ -337,7 +337,12 @@ where
 		ensure!(spot_price.le(&max_amount), Error::<T>::SpotPriceHigherThanMaxAmount);
 
 		// Charge the sending account the spot price
-		T::Currency::withdraw(&sender, spot_price, WithdrawReasons::FEE, existence_requirement)?;
+		let _ = T::Currency::withdraw(
+			&sender,
+			spot_price,
+			WithdrawReasons::FEE,
+			existence_requirement,
+		)?;
 
 		let assignment = Assignment::new(para_id);
 

polkadot/xcm/pallet-xcm/src/mock.rs

@@ -28,9 +28,7 @@ use polkadot_parachain_primitives::primitives::Id as ParaId;
 use polkadot_runtime_parachains::origin;
 use sp_core::H256;
 use sp_runtime::{traits::IdentityLookup, AccountId32, BuildStorage};
-pub use sp_std::{
-	cell::RefCell, collections::btree_map::BTreeMap, fmt::Debug, marker::PhantomData,
-};
+pub use sp_std::cell::RefCell;
 use xcm::prelude::*;
 #[allow(deprecated)]
 use xcm_builder::CurrencyAdapter as XcmCurrencyAdapter;

polkadot/xcm/procedural/src/builder_pattern.rs

@@ -87,8 +87,8 @@ fn generate_builder_raw_impl(name: &Ident, data_enum: &DataEnum) -> TokenStream2
 	let methods = data_enum.variants.iter().map(|variant| {
 		let variant_name = &variant.ident;
 		let method_name_string = &variant_name.to_string().to_snake_case();
-		let method_name = syn::Ident::new(&method_name_string, variant_name.span());
-		let docs = get_doc_comments(&variant);
+		let method_name = syn::Ident::new(method_name_string, variant_name.span());
+		let docs = get_doc_comments(variant);
 		let method = match &variant.fields {
 			Fields::Unit => {
 				quote! {
@@ -148,9 +148,7 @@ fn generate_builder_impl(name: &Ident, data_enum: &DataEnum) -> Result<TokenStre
 		.iter()
 		.map(|variant| {
 			let maybe_builder_attr = variant.attrs.iter().find(|attr| match attr.meta {
-				Meta::List(ref list) => {
-					return list.path.is_ident("builder");
-				},
+				Meta::List(ref list) => list.path.is_ident("builder"),
 				_ => false,
 			});
 			let builder_attr = match maybe_builder_attr {
@@ -159,7 +157,7 @@ fn generate_builder_impl(name: &Ident, data_enum: &DataEnum) -> Result<TokenStre
 				                          * holding register */
 			};
 			let Meta::List(ref list) = builder_attr.meta else { unreachable!("We checked before") };
-			let inner_ident: Ident = syn::parse2(list.tokens.clone().into()).map_err(|_| {
+			let inner_ident: Ident = syn::parse2(list.tokens.clone()).map_err(|_| {
 				Error::new_spanned(&builder_attr, "Expected `builder(loads_holding)`")
 			})?;
 			let ident_to_match: Ident = syn::parse_quote!(loads_holding);
@@ -177,8 +175,8 @@ fn generate_builder_impl(name: &Ident, data_enum: &DataEnum) -> Result<TokenStre
 		.map(|variant| {
 			let variant_name = &variant.ident;
 			let method_name_string = &variant_name.to_string().to_snake_case();
-			let method_name = syn::Ident::new(&method_name_string, variant_name.span());
-			let docs = get_doc_comments(&variant);
+			let method_name = syn::Ident::new(method_name_string, variant_name.span());
+			let docs = get_doc_comments(variant);
 			let method = match &variant.fields {
 				Fields::Unnamed(fields) => {
 					let arg_names: Vec<_> = fields
@@ -217,7 +215,7 @@ fn generate_builder_impl(name: &Ident, data_enum: &DataEnum) -> Result<TokenStre
 				},
 				_ =>
 					return Err(Error::new_spanned(
-						&variant,
+						variant,
 						"Instructions that load the holding register should take operands",
 					)),
 			};
@@ -235,14 +233,14 @@ fn generate_builder_impl(name: &Ident, data_enum: &DataEnum) -> Result<TokenStre
 	let buy_execution_method = data_enum
 		.variants
 		.iter()
-		.find(|variant| variant.ident.to_string() == "BuyExecution")
+		.find(|variant| variant.ident == "BuyExecution")
 		.map_or(
 			Err(Error::new_spanned(&data_enum.variants, "No BuyExecution instruction")),
 			|variant| {
 				let variant_name = &variant.ident;
 				let method_name_string = &variant_name.to_string().to_snake_case();
-				let method_name = syn::Ident::new(&method_name_string, variant_name.span());
-				let docs = get_doc_comments(&variant);
+				let method_name = syn::Ident::new(method_name_string, variant_name.span());
+				let docs = get_doc_comments(variant);
 				let fields = match &variant.fields {
 					Fields::Named(fields) => {
 						let arg_names: Vec<_> =
@@ -263,7 +261,7 @@ fn generate_builder_impl(name: &Ident, data_enum: &DataEnum) -> Result<TokenStre
 					},
 					_ =>
 						return Err(Error::new_spanned(
-							&variant,
+							variant,
 							"BuyExecution should have named fields",
 						)),
 				};
@@ -289,19 +287,19 @@ fn generate_builder_unpaid_impl(name: &Ident, data_enum: &DataEnum) -> Result<To
 	let unpaid_execution_variant = data_enum
 		.variants
 		.iter()
-		.find(|variant| variant.ident.to_string() == "UnpaidExecution")
+		.find(|variant| variant.ident == "UnpaidExecution")
 		.ok_or(Error::new_spanned(&data_enum.variants, "No UnpaidExecution instruction"))?;
 	let unpaid_execution_ident = &unpaid_execution_variant.ident;
 	let unpaid_execution_method_name = Ident::new(
 		&unpaid_execution_ident.to_string().to_snake_case(),
 		unpaid_execution_ident.span(),
 	);
-	let docs = get_doc_comments(&unpaid_execution_variant);
+	let docs = get_doc_comments(unpaid_execution_variant);
 	let fields = match &unpaid_execution_variant.fields {
 		Fields::Named(fields) => fields,
 		_ =>
 			return Err(Error::new_spanned(
-				&unpaid_execution_variant,
+				unpaid_execution_variant,
 				"UnpaidExecution should have named fields",
 			)),
 	};

polkadot/xcm/xcm-builder/src/currency_adapter.rs

@@ -116,7 +116,7 @@ impl<
 		.map_err(|_| XcmError::NotWithdrawable)
 	}
 	fn accrue_checked(checked_account: AccountId, amount: Currency::Balance) {
-		Currency::deposit_creating(&checked_account, amount);
+		let _ = Currency::deposit_creating(&checked_account, amount);
 		Currency::deactivate(amount);
 	}
 	fn reduce_checked(checked_account: AccountId, amount: Currency::Balance) {
@@ -218,7 +218,7 @@ impl<
 		let amount = Matcher::matches_fungible(what).ok_or(Error::AssetNotHandled)?;
 		let who =
 			AccountIdConverter::convert_location(who).ok_or(Error::AccountIdConversionFailed)?;
-		Currency::withdraw(&who, amount, WithdrawReasons::TRANSFER, AllowDeath)
+		let _ = Currency::withdraw(&who, amount, WithdrawReasons::TRANSFER, AllowDeath)
 			.map_err(|e| XcmError::FailedToTransactAsset(e.into()))?;
 		Ok(what.clone().into())
 	}

polkadot/xcm/xcm-builder/src/tests/mock.rs

@@ -27,20 +27,16 @@ pub use crate::{
 };
 use frame_support::traits::{ContainsPair, Everything};
 pub use frame_support::{
-	dispatch::{
-		DispatchInfo, DispatchResultWithPostInfo, GetDispatchInfo, Parameter, PostDispatchInfo,
-	},
+	dispatch::{DispatchInfo, DispatchResultWithPostInfo, GetDispatchInfo, PostDispatchInfo},
 	ensure, match_types, parameter_types,
 	sp_runtime::{traits::Dispatchable, DispatchError, DispatchErrorWithPostInfo},
-	traits::{ConstU32, Contains, Get, IsInVec},
+	traits::{Contains, Get, IsInVec},
 };
 pub use parity_scale_codec::{Decode, Encode};
-pub use sp_io::hashing::blake2_256;
 pub use sp_std::{
 	cell::{Cell, RefCell},
 	collections::{btree_map::BTreeMap, btree_set::BTreeSet},
 	fmt::Debug,
-	marker::PhantomData,
 };
 pub use xcm::latest::{prelude::*, Weight};
 use xcm_executor::traits::{Properties, QueryHandler, QueryResponseStatus};

substrate/client/chain-spec/src/genesis_config_builder.rs

@@ -141,7 +141,7 @@ where
 mod tests {
 	use super::*;
 	use serde_json::{from_str, json};
-	pub use sp_consensus_babe::{AllowedSlots, BabeEpochConfiguration, Slot};
+	pub use sp_consensus_babe::{AllowedSlots, BabeEpochConfiguration};
 
 	#[test]
 	fn get_default_config_works() {

substrate/frame/alliance/src/mock.rs

@@ -19,16 +19,12 @@
 
 pub use sp_core::H256;
 use sp_runtime::traits::Hash;
-pub use sp_runtime::{
-	traits::{BlakeTwo256, IdentityLookup},
-	BuildStorage,
-};
+pub use sp_runtime::{traits::BlakeTwo256, BuildStorage};
 use sp_std::convert::{TryFrom, TryInto};
 
 pub use frame_support::{
 	assert_noop, assert_ok, derive_impl, ord_parameter_types, parameter_types,
-	traits::{EitherOfDiverse, SortedMembers},
-	BoundedVec,
+	traits::EitherOfDiverse, BoundedVec,
 };
 use frame_system::{EnsureRoot, EnsureSignedBy};
 use pallet_identity::{

substrate/frame/assets/src/benchmarking.rs

@@ -102,7 +102,7 @@ fn add_sufficients<T: Config<I>, I: 'static>(minter: T::AccountId, n: u32) {
 
 fn add_approvals<T: Config<I>, I: 'static>(minter: T::AccountId, n: u32) {
 	let asset_id = default_asset_id::<T, I>();
-	T::Currency::deposit_creating(
+	let _ = T::Currency::deposit_creating(
 		&minter,
 		T::ApprovalDeposit::get() * n.into() + T::Currency::minimum_balance(),
 	);

substrate/frame/beefy/src/mock.rs

@@ -37,10 +37,7 @@ use sp_state_machine::BasicExternalities;
 
 use crate as pallet_beefy;
 
-pub use sp_consensus_beefy::{
-	ecdsa_crypto::{AuthorityId as BeefyId, AuthoritySignature as BeefySignature},
-	ConsensusLog, EquivocationProof, BEEFY_ENGINE_ID,
-};
+pub use sp_consensus_beefy::{ecdsa_crypto::AuthorityId as BeefyId, ConsensusLog, BEEFY_ENGINE_ID};
 
 impl_opaque_keys! {
 	pub struct MockSessionKeys {

substrate/frame/broker/src/lib.rs

@@ -42,9 +42,7 @@ pub use weights::WeightInfo;
 pub use adapt_price::*;
 pub use core_mask::*;
 pub use coretime_interface::*;
-pub use nonfungible_impl::*;
 pub use types::*;
-pub use utility_impls::*;
 
 #[frame_support::pallet]
 pub mod pallet {

substrate/frame/contracts/src/migration/v10.rs

@@ -219,7 +219,7 @@ where
 					"Failed to transfer the base deposit, reason: {:?}",
 					err
 				);
-				OldCurrency::deposit_creating(&deposit_account, min_balance);
+				let _ = OldCurrency::deposit_creating(&deposit_account, min_balance);
 				min_balance
 			});
 

substrate/frame/contracts/src/wasm/mod.rs

@@ -25,13 +25,15 @@ mod runtime;
 pub use crate::wasm::runtime::api_doc;
 
 pub use crate::wasm::runtime::{
-	AllowDeprecatedInterface, AllowUnstableInterface, Environment, ReturnErrorCode, Runtime,
-	RuntimeCosts,
+	AllowDeprecatedInterface, AllowUnstableInterface, Environment, Runtime, RuntimeCosts,
 };
-pub use pallet_contracts_uapi::ReturnFlags;
+
 #[cfg(test)]
 pub use tests::MockExt;
 
+#[cfg(test)]
+pub use crate::wasm::runtime::ReturnErrorCode;
+
 use crate::{
 	exec::{ExecResult, Executable, ExportedFunction, Ext},
 	gas::{GasMeter, Token},

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

@@ -21,7 +21,7 @@ use frame_election_provider_support::{
 	bounds::{DataProviderBounds, ElectionBounds},
 	data_provider, onchain, ElectionDataProvider, NposSolution, SequentialPhragmen,
 };
-pub use frame_support::{assert_noop, assert_ok, derive_impl, pallet_prelude::GetDefault};
+pub use frame_support::derive_impl;
 use frame_support::{
 	parameter_types,
 	traits::{ConstU32, Hooks},
@@ -117,7 +117,7 @@ pub fn roll_to_round(n: u32) {
 
 	while MultiPhase::round() != n {
 		roll_to_signed();
-		assert_ok!(MultiPhase::elect());
+		frame_support::assert_ok!(MultiPhase::elect());
 	}
 }
 
@@ -638,9 +638,9 @@ impl ExtBuilder {
 
 		#[cfg(feature = "try-runtime")]
 		ext.execute_with(|| {
-			assert_ok!(<MultiPhase as frame_support::traits::Hooks<u64>>::try_state(
-				System::block_number()
-			));
+			frame_support::assert_ok!(
+				<MultiPhase as frame_support::traits::Hooks<u64>>::try_state(System::block_number())
+			);
 		});
 	}
 }

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

@@ -38,7 +38,7 @@ fn endowed_account<T: Config>(name: &'static str, index: u32) -> T::AccountId {
 	let _ = T::Currency::make_free_balance_be(&account, amount);
 	// important to increase the total issuance since T::CurrencyToVote will need it to be sane for
 	// phragmen to work.
-	T::Currency::issue(amount);
+	let _ = T::Currency::issue(amount);
 
 	account
 }

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

@@ -571,7 +571,7 @@ pub mod pallet {
 					.any(|e| T::Staking::is_exposed_in_era(&stash, e));
 
 				if is_exposed {
-					T::Currency::slash_reserved(&stash, deposit);
+					let _ = T::Currency::slash_reserved(&stash, deposit);
 					log!(info, "slashed {:?} by {:?}", stash, deposit);
 					Self::deposit_event(Event::<T>::Slashed { stash, amount: deposit });
 					false

substrate/frame/indices/src/lib.rs

@@ -223,7 +223,7 @@ pub mod pallet {
 				let (account, amount, perm) = maybe_value.take().ok_or(Error::<T>::NotAssigned)?;
 				ensure!(!perm, Error::<T>::Permanent);
 				ensure!(account == who, Error::<T>::NotOwner);
-				T::Currency::slash_reserved(&who, amount);
+				let _ = T::Currency::slash_reserved(&who, amount);
 				*maybe_value = Some((account, Zero::zero(), true));
 				Ok(())
 			})?;

substrate/frame/lottery/src/lib.rs

@@ -368,7 +368,8 @@ pub mod pallet {
 			// Make sure pot exists.
 			let lottery_account = Self::account_id();
 			if T::Currency::total_balance(&lottery_account).is_zero() {
-				T::Currency::deposit_creating(&lottery_account, T::Currency::minimum_balance());
+				let _ =
+					T::Currency::deposit_creating(&lottery_account, T::Currency::minimum_balance());
 			}
 			Self::deposit_event(Event::<T>::LotteryStarted);
 			Ok(())

substrate/frame/paged-list/src/paged_list.rs

@@ -407,13 +407,11 @@ where
 #[allow(dead_code)]
 pub(crate) mod mock {
 	pub use super::*;
-	pub use frame_support::{
-		parameter_types,
-		storage::{types::ValueQuery, StorageList as _},
-		StorageNoopGuard,
-	};
-	pub use sp_io::{hashing::twox_128, TestExternalities};
-	pub use sp_metadata_ir::{StorageEntryModifierIR, StorageEntryTypeIR, StorageHasherIR};
+	pub use frame_support::parameter_types;
+	#[cfg(test)]
+	pub use frame_support::{storage::StorageList as _, StorageNoopGuard};
+	#[cfg(test)]
+	pub use sp_io::TestExternalities;
 
 	parameter_types! {
 		pub const ValuesPerNewPage: u32 = 5;

substrate/frame/staking/src/benchmarking.rs

@@ -250,7 +250,7 @@ benchmarks! {
 		let original_bonded: BalanceOf<T>
 			= Ledger::<T>::get(&controller).map(|l| l.active).ok_or("ledger not created after")?;
 
-		T::Currency::deposit_into_existing(&stash, max_additional).unwrap();
+		let _ = T::Currency::deposit_into_existing(&stash, max_additional).unwrap();
 
 		whitelist_account!(stash);
 	}: _(RawOrigin::Signed(stash), max_additional)

substrate/frame/support/src/dispatch.rs

@@ -664,7 +664,7 @@ mod weight_tests {
 	use sp_runtime::{generic, traits::BlakeTwo256};
 	use sp_weights::RuntimeDbWeight;
 
-	pub use self::frame_system::{Call, Config, Pallet};
+	pub use self::frame_system::{Call, Config};
 
 	fn from_actual_ref_time(ref_time: Option<u64>) -> PostDispatchInfo {
 		PostDispatchInfo {

substrate/primitives/database/src/lib.rs

@@ -101,7 +101,9 @@ pub trait Database<H: Clone + AsRef<[u8]>>: Send + Sync {
 	/// This may be faster than `get` since it doesn't allocate.
 	/// Use `with_get` helper function if you need `f` to return a value from `f`
 	fn with_get(&self, col: ColumnId, key: &[u8], f: &mut dyn FnMut(&[u8])) {
-		self.get(col, key).map(|v| f(&v));
+		if let Some(v) = self.get(col, key) {
+			f(&v)
+		}
 	}
 
 	/// Check if database supports internal ref counting for state data.

substrate/primitives/runtime-interface/proc-macro/src/utils.rs

@@ -89,7 +89,7 @@ struct RuntimeInterfaceFunctionSet {
 impl RuntimeInterfaceFunctionSet {
 	fn new(version: VersionAttribute, trait_item: &TraitItemFn) -> Result<Self> {
 		Ok(Self {
-			latest_version_to_call: version.is_callable().then(|| version.version),
+			latest_version_to_call: version.is_callable().then_some(version.version),
 			versions: BTreeMap::from([(
 				version.version,
 				RuntimeInterfaceFunction::new(trait_item)?,

substrate/primitives/storage/src/lib.rs

@@ -414,12 +414,13 @@ impl ChildTrieParentKeyId {
 ///
 /// V0 and V1 uses a same trie implementation, but V1 will write external value node in the trie for
 /// value with size at least `TRIE_VALUE_NODE_THRESHOLD`.
-#[derive(Debug, Clone, Copy, Eq, PartialEq)]
+#[derive(Debug, Default, Clone, Copy, Eq, PartialEq)]
 #[cfg_attr(feature = "std", derive(Encode, Decode))]
 pub enum StateVersion {
 	/// Old state version, no value nodes.
 	V0 = 0,
 	/// New state version can use value nodes.
+	#[default]
 	V1 = 1,
 }
 
@@ -432,12 +433,6 @@ impl Display for StateVersion {
 	}
 }
 
-impl Default for StateVersion {
-	fn default() -> Self {
-		StateVersion::V1
-	}
-}
-
 impl From<StateVersion> for u8 {
 	fn from(version: StateVersion) -> u8 {
 		version as u8

substrate/utils/build-script-utils/src/git.rs

@@ -15,7 +15,13 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use std::{env, fs, fs::File, io, io::Read, path::PathBuf};
+use std::{
+	env, fs,
+	fs::File,
+	io,
+	io::Read,
+	path::{Path, PathBuf},
+};
 
 /// Make sure the calling `build.rs` script is rerun when `.git/HEAD` or the ref of `.git/HEAD`
 /// changed.
@@ -55,7 +61,7 @@ pub fn rerun_if_git_head_changed() {
 }
 
 // Code taken from https://github.com/rustyhorde/vergen/blob/8d522db8c8e16e26c0fc9ea8e6b0247cbf5cca84/src/output/envvar.rs
-fn get_git_paths(path: &PathBuf) -> Result<Option<Vec<PathBuf>>, io::Error> {
+fn get_git_paths(path: &Path) -> Result<Option<Vec<PathBuf>>, io::Error> {
 	let git_dir_or_file = path.join(".git");
 
 	if let Ok(metadata) = fs::metadata(&git_dir_or_file) {

substrate/utils/build-script-utils/src/version.rs

@@ -25,7 +25,7 @@ pub fn generate_cargo_keys() {
 		// We deliberately set the length here to `11` to ensure that
 		// the emitted hash is always of the same length; otherwise
 		// it can (and will!) vary between different build environments.
-		match Command::new("git").args(&["rev-parse", "--short=11", "HEAD"]).output() {
+		match Command::new("git").args(["rev-parse", "--short=11", "HEAD"]).output() {
 			Ok(o) if o.status.success() => {
 				let sha = String::from_utf8_lossy(&o.stdout).trim().to_owned();
 				Cow::from(sha)