Introduce DispatchInfoOf type alias

frame/contracts/src/lib.rs

@@ -113,7 +113,10 @@ use sp_std::{prelude::*, marker::PhantomData, fmt::Debug};
 use codec::{Codec, Encode, Decode};
 use sp_io::hashing::blake2_256;
 use sp_runtime::{
-	traits::{Hash, StaticLookup, Zero, MaybeSerializeDeserialize, Member, SignedExtension},
+	traits::{
+		Hash, StaticLookup, Zero, MaybeSerializeDeserialize, Member, SignedExtension,
+		DispatchInfoOf,
+	},
 	transaction_validity::{
 		ValidTransaction, InvalidTransaction, TransactionValidity, TransactionValidityError,
 	},
@@ -1098,7 +1101,7 @@ impl<T: Trait + Send + Sync> SignedExtension for CheckBlockGasLimit<T> {
 		&self,
 		_: &Self::AccountId,
 		call: &Self::Call,
-		_: &<Self::Call as Dispatchable>::Info,
+		_: &DispatchInfoOf<Self::Call>,
 		_: usize,
 	) -> TransactionValidity {
 		let call = match call.is_sub_type() {

frame/example/src/lib.rs

@@ -264,7 +264,9 @@ use sp_std::prelude::*;
 use frame_system::{self as system, ensure_signed, ensure_root};
 use codec::{Encode, Decode};
 use sp_runtime::{
-	traits::{SignedExtension, Bounded, SaturatedConversion, Dispatchable},
+	traits::{
+		SignedExtension, Bounded, SaturatedConversion, DispatchInfoOf,
+	},
 	transaction_validity::{
 		ValidTransaction, TransactionValidityError, InvalidTransaction, TransactionValidity,
 	},
@@ -626,7 +628,7 @@ impl<T: Trait + Send + Sync> SignedExtension for WatchDummy<T> {
 		&self,
 		_who: &Self::AccountId,
 		call: &Self::Call,
-		_info: &<Self::Call as Dispatchable>::Info,
+		_info: &DispatchInfoOf<Self::Call>,
 		len: usize,
 	) -> TransactionValidity {
 		// if the transaction is too big, just drop it.

frame/staking/src/lib.rs

@@ -288,7 +288,7 @@ use sp_runtime::{
 	curve::PiecewiseLinear,
 	traits::{
 		Convert, Zero, StaticLookup, CheckedSub, Saturating, SaturatedConversion, AtLeast32Bit,
-		SignedExtension, Dispatchable
+		SignedExtension, Dispatchable, DispatchInfoOf,
 	},
 	transaction_validity::{
 		TransactionValidityError, TransactionValidity, ValidTransaction, InvalidTransaction,
@@ -3133,7 +3133,7 @@ impl<T: Trait + Send + Sync> SignedExtension for LockStakingStatus<T> {
 		&self,
 		_who: &Self::AccountId,
 		call: &Self::Call,
-		_info: &<Self::Call as Dispatchable>::Info,
+		_info: &DispatchInfoOf<Self::Call>,
 		_len: usize,
 	) -> TransactionValidity {
 		if let Some(inner_call) = call.is_sub_type() {

frame/system/src/lib.rs

@@ -109,7 +109,7 @@ use sp_runtime::{
 		self, CheckEqual, AtLeast32Bit, Zero, SignedExtension, Lookup, LookupError,
 		SimpleBitOps, Hash, Member, MaybeDisplay, BadOrigin, SaturatedConversion,
 		MaybeSerialize, MaybeSerializeDeserialize, MaybeMallocSizeOf, StaticLookup, One, Bounded,
-		Dispatchable,
+		Dispatchable, DispatchInfoOf, PostDispatchInfoOf,
 	},
 };
 
@@ -1183,7 +1183,7 @@ impl<T: Trait + Send + Sync> CheckWeight<T> where
 	///
 	/// Upon successes, it returns the new block weight as a `Result`.
 	fn check_weight(
-		info: &<T::Call as Dispatchable>::Info,
+		info: &DispatchInfoOf<T::Call>,
 	) -> Result<Weight, TransactionValidityError> {
 		let current_weight = Module::<T>::all_extrinsics_weight();
 		let maximum_weight = T::MaximumBlockWeight::get();
@@ -1201,7 +1201,7 @@ impl<T: Trait + Send + Sync> CheckWeight<T> where
 	///
 	/// Upon successes, it returns the new block length as a `Result`.
 	fn check_block_length(
-		info: &<T::Call as Dispatchable>::Info,
+		info: &DispatchInfoOf<T::Call>,
 		len: usize,
 	) -> Result<u32, TransactionValidityError> {
 		let current_len = Module::<T>::all_extrinsics_len();
@@ -1217,7 +1217,7 @@ impl<T: Trait + Send + Sync> CheckWeight<T> where
 	}
 
 	/// get the priority of an extrinsic denoted by `info`.
-	fn get_priority(info: &<T::Call as Dispatchable>::Info) -> TransactionPriority {
+	fn get_priority(info: &DispatchInfoOf<T::Call>) -> TransactionPriority {
 		match info.class {
 			DispatchClass::Normal => info.weight.into(),
 			DispatchClass::Operational => Bounded::max_value(),
@@ -1235,7 +1235,7 @@ impl<T: Trait + Send + Sync> CheckWeight<T> where
 	///
 	/// It checks and notes the new weight and length.
 	fn do_pre_dispatch(
-		info: &<T::Call as Dispatchable>::Info,
+		info: &DispatchInfoOf<T::Call>,
 		len: usize,
 	) -> Result<(), TransactionValidityError> {
 		let next_len = Self::check_block_length(info, len)?;
@@ -1249,7 +1249,7 @@ impl<T: Trait + Send + Sync> CheckWeight<T> where
 	///
 	/// It only checks that the block weight and length limit will not exceed.
 	fn do_validate(
-		info: &<T::Call as Dispatchable>::Info,
+		info: &DispatchInfoOf<T::Call>,
 		len: usize,
 	) -> TransactionValidity {
 		// ignore the next weight and length. If they return `Ok`, then it is below the limit.
@@ -1275,7 +1275,7 @@ impl<T: Trait + Send + Sync> SignedExtension for CheckWeight<T> where
 		self,
 		_who: &Self::AccountId,
 		_call: &Self::Call,
-		info: &<Self::Call as Dispatchable>::Info,
+		info: &DispatchInfoOf<Self::Call>,
 		len: usize,
 	) -> Result<(), TransactionValidityError> {
 		if info.class == DispatchClass::Mandatory {
@@ -1288,7 +1288,7 @@ impl<T: Trait + Send + Sync> SignedExtension for CheckWeight<T> where
 		&self,
 		_who: &Self::AccountId,
 		_call: &Self::Call,
-		info: &<Self::Call as Dispatchable>::Info,
+		info: &DispatchInfoOf<Self::Call>,
 		len: usize,
 	) -> TransactionValidity {
 		if info.class == DispatchClass::Mandatory {
@@ -1299,24 +1299,24 @@ impl<T: Trait + Send + Sync> SignedExtension for CheckWeight<T> where
 
 	fn pre_dispatch_unsigned(
 		_call: &Self::Call,
-		info: &<Self::Call as Dispatchable>::Info,
+		info: &DispatchInfoOf<Self::Call>,
 		len: usize,
 	) -> Result<(), TransactionValidityError> {
 		Self::do_pre_dispatch(info, len)
 	}
 
 	fn validate_unsigned(
 		_call: &Self::Call,
-		info: &<Self::Call as Dispatchable>::Info,
+		info: &DispatchInfoOf<Self::Call>,
 		len: usize,
 	) -> TransactionValidity {
 		Self::do_validate(info, len)
 	}
 
 	fn post_dispatch(
 		_pre: Self::Pre,
-		info: &<Self::Call as Dispatchable>::Info,
-		_post_info: &<Self::Call as Dispatchable>::PostInfo,
+		info: &DispatchInfoOf<Self::Call>,
+		_post_info: &PostDispatchInfoOf<Self::Call>,
 		_len: usize,
 		result: &DispatchResult,
 	) -> Result<(), TransactionValidityError> {
@@ -1380,7 +1380,7 @@ impl<T: Trait> SignedExtension for CheckNonce<T> where
 		self,
 		who: &Self::AccountId,
 		_call: &Self::Call,
-		_info: &<Self::Call as Dispatchable>::Info,
+		_info: &DispatchInfoOf<Self::Call>,
 		_len: usize,
 	) -> Result<(), TransactionValidityError> {
 		let mut account = Account::<T>::get(who);
@@ -1402,7 +1402,7 @@ impl<T: Trait> SignedExtension for CheckNonce<T> where
 		&self,
 		who: &Self::AccountId,
 		_call: &Self::Call,
-		info: &<Self::Call as Dispatchable>::Info,
+		info: &DispatchInfoOf<Self::Call>,
 		_len: usize,
 	) -> TransactionValidity {
 		// check index
@@ -1468,7 +1468,7 @@ impl<T: Trait + Send + Sync> SignedExtension for CheckEra<T> {
 		&self,
 		_who: &Self::AccountId,
 		_call: &Self::Call,
-		_info: &<Self::Call as Dispatchable>::Info,
+		_info: &DispatchInfoOf<Self::Call>,
 		_len: usize,
 	) -> TransactionValidity {
 		let current_u64 = <Module<T>>::block_number().saturated_into::<u64>();

frame/transaction-payment/src/lib.rs

@@ -44,7 +44,10 @@ use sp_runtime::{
 		TransactionPriority, ValidTransaction, InvalidTransaction, TransactionValidityError,
 		TransactionValidity,
 	},
-	traits::{Zero, Saturating, SignedExtension, SaturatedConversion, Convert, Dispatchable},
+	traits::{
+		Zero, Saturating, SignedExtension, SaturatedConversion, Convert, Dispatchable,
+		DispatchInfoOf,
+	},
 };
 use pallet_transaction_payment_rpc_runtime_api::RuntimeDispatchInfo;
 
@@ -160,7 +163,7 @@ impl<T: Trait + Send + Sync> ChargeTransactionPayment<T> where
 	/// final_fee = base_fee + targeted_fee_adjustment(len_fee + weight_fee) + tip;
 	pub fn compute_fee(
 		len: u32,
-		info: &<T::Call as Dispatchable>::Info,
+		info: &DispatchInfoOf<T::Call>,
 		tip: BalanceOf<T>,
 	) -> BalanceOf<T>
 	where
@@ -219,7 +222,7 @@ impl<T: Trait + Send + Sync> SignedExtension for ChargeTransactionPayment<T> whe
 		&self,
 		who: &Self::AccountId,
 		_call: &Self::Call,
-		info: &<Self::Call as Dispatchable>::Info,
+		info: &DispatchInfoOf<Self::Call>,
 		len: usize,
 	) -> TransactionValidity {
 		// pay any fees.

primitives/runtime/src/generic/checked_extrinsic.rs

@@ -18,9 +18,8 @@
 //! stage.
 
 use crate::traits::{
-	self, Member, MaybeDisplay, SignedExtension, Dispatchable,
+	self, Member, MaybeDisplay, SignedExtension, Dispatchable, DispatchInfoOf, ValidateUnsigned,
 };
-use crate::traits::ValidateUnsigned;
 use crate::transaction_validity::{TransactionValidity, TransactionSource};
 
 /// Definition of something that the external world might want to say; its
@@ -51,7 +50,7 @@ where
 		// TODO [#5006;ToDr] should source be passed to `SignedExtension`s?
 		// Perhaps a change for 2.0 to avoid breaking too much APIs?
 		source: TransactionSource,
-		info: &<Self::Call as Dispatchable>::Info,
+		info: &DispatchInfoOf<Self::Call>,
 		len: usize,
 	) -> TransactionValidity {
 		if let Some((ref id, ref extra)) = self.signed {
@@ -65,7 +64,7 @@ where
 
 	fn apply<U: ValidateUnsigned<Call=Self::Call>>(
 		self,
-		info: &<Self::Call as Dispatchable>::Info,
+		info: &DispatchInfoOf<Self::Call>,
 		len: usize,
 	) -> crate::ApplyExtrinsicResult {
 		let (maybe_who, pre) = if let Some((id, extra)) = self.signed {

primitives/runtime/src/testing.rs

@@ -21,7 +21,7 @@ use std::{fmt::Debug, ops::Deref, fmt, cell::RefCell};
 use crate::codec::{Codec, Encode, Decode};
 use crate::traits::{
 	self, Checkable, Applyable, BlakeTwo256, OpaqueKeys,
-	SignedExtension, Dispatchable,
+	SignedExtension, Dispatchable, DispatchInfoOf,
 };
 use crate::traits::ValidateUnsigned;
 use crate::{generic, KeyTypeId, ApplyExtrinsicResult};
@@ -356,7 +356,7 @@ impl<Origin, Call, Extra> Applyable for TestXt<Call, Extra> where
 	fn validate<U: ValidateUnsigned<Call=Self::Call>>(
 		&self,
 		_source: TransactionSource,
-		_info: &<Self::Call as Dispatchable>::Info,
+		_info: &DispatchInfoOf<Self::Call>,
 		_len: usize,
 	) -> TransactionValidity {
 		Ok(Default::default())
@@ -366,7 +366,7 @@ impl<Origin, Call, Extra> Applyable for TestXt<Call, Extra> where
 	/// index and sender.
 	fn apply<U: ValidateUnsigned<Call=Self::Call>>(
 		self,
-		info: &<Self::Call as Dispatchable>::Info,
+		info: &DispatchInfoOf<Self::Call>,
 		len: usize,
 	) -> ApplyExtrinsicResult {
 		let maybe_who = if let Some((who, extra)) = self.signature {

primitives/runtime/src/traits.rs

@@ -636,6 +636,11 @@ pub trait Dispatchable {
 	fn dispatch(self, origin: Self::Origin) -> crate::DispatchResultWithInfo<Self::PostInfo>;
 }
 
+/// Shortcut to reference the `Info` type of a `Dispatchable`.
+pub type DispatchInfoOf<T> = <T as Dispatchable>::Info;
+/// Shortcut to reference the `PostInfo` type of a `Dispatchable`.
+pub type PostDispatchInfoOf<T> = <T as Dispatchable>::PostInfo;
+
 impl Dispatchable for () {
 	type Origin = ();
 	type Trait = ();
@@ -685,7 +690,7 @@ pub trait SignedExtension: Codec + Debug + Sync + Send + Clone + Eq + PartialEq
 		&self,
 		_who: &Self::AccountId,
 		_call: &Self::Call,
-		_info: &<Self::Call as Dispatchable>::Info,
+		_info: &DispatchInfoOf<Self::Call>,
 		_len: usize,
 	) -> TransactionValidity {
 		Ok(ValidTransaction::default())
@@ -703,7 +708,7 @@ pub trait SignedExtension: Codec + Debug + Sync + Send + Clone + Eq + PartialEq
 		self,
 		who: &Self::AccountId,
 		call: &Self::Call,
-		info: &<Self::Call as Dispatchable>::Info,
+		info: &DispatchInfoOf<Self::Call>,
 		len: usize,
 	) -> Result<Self::Pre, TransactionValidityError> {
 		self.validate(who, call, info.clone(), len)
@@ -721,7 +726,7 @@ pub trait SignedExtension: Codec + Debug + Sync + Send + Clone + Eq + PartialEq
 	/// Make sure to perform the same checks in `pre_dispatch_unsigned` function.
 	fn validate_unsigned(
 		_call: &Self::Call,
-		_info: &<Self::Call as Dispatchable>::Info,
+		_info: &DispatchInfoOf<Self::Call>,
 		_len: usize,
 	) -> TransactionValidity {
 		Ok(ValidTransaction::default())
@@ -737,7 +742,7 @@ pub trait SignedExtension: Codec + Debug + Sync + Send + Clone + Eq + PartialEq
 	/// perform the same validation as in `validate_unsigned`.
 	fn pre_dispatch_unsigned(
 		call: &Self::Call,
-		info: &<Self::Call as Dispatchable>::Info,
+		info: &DispatchInfoOf<Self::Call>,
 		len: usize,
 	) -> Result<Self::Pre, TransactionValidityError> {
 		Self::validate_unsigned(call, info.clone(), len)
@@ -760,8 +765,8 @@ pub trait SignedExtension: Codec + Debug + Sync + Send + Clone + Eq + PartialEq
 	/// will come from either an offchain-worker or via `InherentData`.
 	fn post_dispatch(
 		_pre: Self::Pre,
-		_info: &<Self::Call as Dispatchable>::Info,
-		_post_info: &<Self::Call as Dispatchable>::PostInfo,
+		_info: &DispatchInfoOf<Self::Call>,
+		_post_info: &PostDispatchInfoOf<Self::Call>,
 		_len: usize,
 		_result: &DispatchResult,
 	) -> Result<(), TransactionValidityError> {
@@ -797,23 +802,23 @@ impl<AccountId, Call: Dispatchable> SignedExtension for Tuple {
 		&self,
 		who: &Self::AccountId,
 		call: &Self::Call,
-		info: &<Self::Call as Dispatchable>::Info,
+		info: &DispatchInfoOf<Self::Call>,
 		len: usize,
 	) -> TransactionValidity {
 		let valid = ValidTransaction::default();
 		for_tuples!( #( let valid = valid.combine_with(Tuple.validate(who, call, info, len)?); )* );
 		Ok(valid)
 	}
 
-	fn pre_dispatch(self, who: &Self::AccountId, call: &Self::Call, info: &<Self::Call as Dispatchable>::Info, len: usize)
+	fn pre_dispatch(self, who: &Self::AccountId, call: &Self::Call, info: &DispatchInfoOf<Self::Call>, len: usize)
 		-> Result<Self::Pre, TransactionValidityError>
 	{
 		Ok(for_tuples!( ( #( Tuple.pre_dispatch(who, call, info, len)? ),* ) ))
 	}
 
 	fn validate_unsigned(
 		call: &Self::Call,
-		info: &<Self::Call as Dispatchable>::Info,
+		info: &DispatchInfoOf<Self::Call>,
 		len: usize,
 	) -> TransactionValidity {
 		let valid = ValidTransaction::default();
@@ -823,16 +828,16 @@ impl<AccountId, Call: Dispatchable> SignedExtension for Tuple {
 
 	fn pre_dispatch_unsigned(
 		call: &Self::Call,
-		info: &<Self::Call as Dispatchable>::Info,
+		info: &DispatchInfoOf<Self::Call>,
 		len: usize,
 	) -> Result<Self::Pre, TransactionValidityError> {
 		Ok(for_tuples!( ( #( Tuple::pre_dispatch_unsigned(call, info, len)? ),* ) ))
 	}
 
 	fn post_dispatch(
 		pre: Self::Pre,
-		info: &<Self::Call as Dispatchable>::Info,
-		post_info: &<Self::Call as Dispatchable>::PostInfo,
+		info: &DispatchInfoOf<Self::Call>,
+		post_info: &PostDispatchInfoOf<Self::Call>,
 		len: usize,
 		result: &DispatchResult,
 	) -> Result<(), TransactionValidityError> {
@@ -872,15 +877,15 @@ pub trait Applyable: Sized + Send + Sync {
 	fn validate<V: ValidateUnsigned<Call=Self::Call>>(
 		&self,
 		source: TransactionSource,
-		info: &<Self::Call as Dispatchable>::Info,
+		info: &DispatchInfoOf<Self::Call>,
 		len: usize,
 	) -> TransactionValidity;
 
 	/// Executes all necessary logic needed prior to dispatch and deconstructs into function call,
 	/// index and sender.
 	fn apply<V: ValidateUnsigned<Call=Self::Call>>(
 		self,
-		info: &<Self::Call as Dispatchable>::Info,
+		info: &DispatchInfoOf<Self::Call>,
 		len: usize,
 	) -> crate::ApplyExtrinsicResult;
 }