Move LockableCurrency trait to fungibles::Lockable and deprecate LockableCurrency (#12798)

* WIP move LockableCurrency to fungibles

* rename Lockable and LockIdentifier to funginbles::*

* fix imports further

* change Lockable from fungible to fungibles

* reintroduce LockableCurrency but marked as deprecated

* fix imports

* fix imports

* cargo fmt

* add allow deprecated warnings

* remove unused benchmark import

* fix some of the docs

* fix failing doctest check

* reexport LockIdentifier and LockableCurrency from support/traits

* reexport LockIdentifier and LockableCurrency from support/traits

* allow using deprecated re-export

* replace LockableCurrency and LockIdentifier with a module alias

* Update frame/support/src/traits/tokens/fungibles/lockable.rs

* Update frame/staking/src/pallet/mod.rs

Co-authored-by: Squirrel <gilescope@gmail.com>

* Update frame/support/src/traits.rs

Co-authored-by: Squirrel <gilescope@gmail.com>

* REVERT removing fungibles::Lockable import

Co-authored-by: parity-processbot <>
Co-authored-by: Squirrel <gilescope@gmail.com>

substrate/frame/support/src/traits.rs

@@ -20,6 +20,7 @@
 //! NOTE: If you're looking for `parameter_types`, it has moved in to the top-level module.
 
 pub mod tokens;
+#[allow(deprecated)]
 pub use tokens::{
 	currency::{
 		ActiveIssuanceOf, Currency, LockIdentifier, LockableCurrency, NamedReservableCurrency,

substrate/frame/support/src/traits/tokens/currency.rs

@@ -32,7 +32,10 @@ use sp_std::fmt::Debug;
 mod reservable;
 pub use reservable::{NamedReservableCurrency, ReservableCurrency};
 mod lockable;
-pub use lockable::{LockIdentifier, LockableCurrency, VestingSchedule};
+
+#[deprecated(note = "Deprecated in favour of using fungibles::Lockable trait directly")]
+pub use super::fungibles::{LockIdentifier, Lockable as LockableCurrency};
+pub use lockable::VestingSchedule;
 
 /// Abstraction over a fungible assets system.
 pub trait Currency<AccountId> {

substrate/frame/support/src/traits/tokens/currency/lockable.rs

@@ -17,52 +17,8 @@
 
 //! The lockable currency trait and some associated types.
 
-use super::{super::misc::WithdrawReasons, Currency};
-use crate::{dispatch::DispatchResult, traits::misc::Get};
-
-/// An identifier for a lock. Used for disambiguating different locks so that
-/// they can be individually replaced or removed.
-pub type LockIdentifier = [u8; 8];
-
-/// A currency whose accounts can have liquidity restrictions.
-pub trait LockableCurrency<AccountId>: Currency<AccountId> {
-	/// The quantity used to denote time; usually just a `BlockNumber`.
-	type Moment;
-
-	/// The maximum number of locks a user should have on their account.
-	type MaxLocks: Get<u32>;
-
-	/// Create a new balance lock on account `who`.
-	///
-	/// If the new lock is valid (i.e. not already expired), it will push the struct to
-	/// the `Locks` vec in storage. Note that you can lock more funds than a user has.
-	///
-	/// If the lock `id` already exists, this will update it.
-	fn set_lock(
-		id: LockIdentifier,
-		who: &AccountId,
-		amount: Self::Balance,
-		reasons: WithdrawReasons,
-	);
-
-	/// Changes a balance lock (selected by `id`) so that it becomes less liquid in all
-	/// parameters or creates a new one if it does not exist.
-	///
-	/// Calling `extend_lock` on an existing lock `id` differs from `set_lock` in that it
-	/// applies the most severe constraints of the two, while `set_lock` replaces the lock
-	/// with the new parameters. As in, `extend_lock` will set:
-	/// - maximum `amount`
-	/// - bitwise mask of all `reasons`
-	fn extend_lock(
-		id: LockIdentifier,
-		who: &AccountId,
-		amount: Self::Balance,
-		reasons: WithdrawReasons,
-	);
-
-	/// Remove an existing lock.
-	fn remove_lock(id: LockIdentifier, who: &AccountId);
-}
+use super::Currency;
+use crate::dispatch::DispatchResult;
 
 /// A vesting schedule over a currency. This allows a particular currency to have vesting limits
 /// applied to it.

substrate/frame/support/src/traits/tokens/fungible.rs

@@ -29,6 +29,7 @@ use sp_runtime::traits::Saturating;
 
 mod balanced;
 mod imbalance;
+
 pub use balanced::{Balanced, Unbalanced};
 pub use imbalance::{CreditOf, DebtOf, HandleImbalanceDrop, Imbalance};
 

substrate/frame/support/src/traits/tokens/fungibles.rs

@@ -33,7 +33,9 @@ pub mod metadata;
 pub use balanced::{Balanced, Unbalanced};
 mod imbalance;
 pub use imbalance::{CreditOf, DebtOf, HandleImbalanceDrop, Imbalance};
+mod lockable;
 pub mod roles;
+pub use lockable::{LockIdentifier, Lockable};
 
 /// Trait for providing balance-inspection access to a set of named fungible assets.
 pub trait Inspect<AccountId> {

substrate/frame/support/src/traits/tokens/fungibles/lockable.rs

@@ -0,0 +1,65 @@
+// This file is part of Substrate.
+
+// Copyright (C) 2019-2022 Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! The Lockable trait and some associated types.
+
+use super::{super::misc::WithdrawReasons, currency::Currency};
+use crate::traits::misc::Get;
+
+/// An identifier for a lock. Used for disambiguating different locks so that
+/// they can be individually replaced or removed.
+pub type LockIdentifier = [u8; 8];
+
+/// A currency whose accounts can have liquidity restrictions.
+pub trait Lockable<AccountId>: Currency<AccountId> {
+	/// The quantity used to denote time; usually just a `BlockNumber`.
+	type Moment;
+
+	/// The maximum number of locks a user should have on their account.
+	type MaxLocks: Get<u32>;
+
+	/// Create a new balance lock on account `who`.
+	///
+	/// If the new lock is valid (i.e. not already expired), it will push the struct to
+	/// the `Locks` vec in storage. Note that you can lock more funds than a user has.
+	///
+	/// If the lock `id` already exists, this will update it.
+	fn set_lock(
+		id: LockIdentifier,
+		who: &AccountId,
+		amount: Self::Balance,
+		reasons: WithdrawReasons,
+	);
+
+	/// Changes a balance lock (selected by `id`) so that it becomes less liquid in all
+	/// parameters or creates a new one if it does not exist.
+	///
+	/// Calling `extend_lock` on an existing lock `id` differs from `set_lock` in that it
+	/// applies the most severe constraints of the two, while `set_lock` replaces the lock
+	/// with the new parameters. As in, `extend_lock` will set:
+	/// - maximum `amount`
+	/// - bitwise mask of all `reasons`
+	fn extend_lock(
+		id: LockIdentifier,
+		who: &AccountId,
+		amount: Self::Balance,
+		reasons: WithdrawReasons,
+	);
+
+	/// Remove an existing lock.
+	fn remove_lock(id: LockIdentifier, who: &AccountId);
+}