Indices maintenance (#1705)

* Migrate the indicies crate to 2018 edition.

* Use .cloned() instead of .map(|x| x.clone())

* Update documentation.

substrate/srml/indices/Cargo.toml

@@ -2,6 +2,7 @@
 name = "srml-indices"
 version = "0.1.0"
 authors = ["Parity Technologies <admin@parity.io>"]
+edition = "2018"
 
 [dependencies]
 hex-literal = "0.1.0"
@@ -10,12 +11,12 @@ safe-mix = { version = "1.0", default-features = false}
 parity-codec = { version = "3.0", default-features = false }
 parity-codec-derive = { version = "3.0", default-features = false }
 substrate-keyring = { path = "../../core/keyring", optional = true }
-substrate-primitives = { path = "../../core/primitives", default-features = false }
-sr-std = { path = "../../core/sr-std", default-features = false }
-sr-io = { path = "../../core/sr-io", default-features = false }
-sr-primitives = { path = "../../core/sr-primitives", default-features = false }
+rstd = { package = "sr-std", path = "../../core/sr-std", default-features = false }
+runtime-io = { package = "sr-io", path = "../../core/sr-io", default-features = false }
+primitives = { package = "sr-primitives", path = "../../core/sr-primitives", default-features = false }
 srml-support = { path = "../support", default-features = false }
-srml-system = { path = "../system", default-features = false }
+system = { package = "srml-system", path = "../system", default-features = false }
+substrate-primitives = { path = "../../core/primitives", default-features = false }
 
 [dev-dependencies]
 ref_thread_local = "0.0"
@@ -29,9 +30,9 @@ std = [
 	"parity-codec/std",
 	"parity-codec-derive/std",
 	"substrate-primitives/std",
-	"sr-std/std",
-	"sr-io/std",
+	"rstd/std",
+	"runtime-io/std",
 	"srml-support/std",
-	"sr-primitives/std",
-	"srml-system/std",
+	"primitives/std",
+	"system/std",
 ]

substrate/srml/indices/src/address.rs

@@ -18,9 +18,10 @@
 
 #[cfg(feature = "std")]
 use std::fmt;
-use super::{Member, Decode, Encode, As, Input, Output};
+use crate::{Member, Decode, Encode, As, Input, Output};
 
-/// A vetted and verified extrinsic from the external world.
+/// An indices-aware address, which can be either a direct `AccountId` or
+/// an index.
 #[derive(PartialEq, Eq, Clone)]
 #[cfg_attr(feature = "std", derive(Debug, Hash))]
 pub enum Address<AccountId, AccountIndex> where

substrate/srml/indices/src/lib.rs

@@ -14,43 +14,26 @@
 // You should have received a copy of the GNU General Public License
 // along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
 
-//! Balances: Handles setting and retrieval of free balance,
-//! retrieving total balance, reserve and unreserve balance,
-//! repatriating a reserved balance to a beneficiary account that exists,
-//! transfering a balance between accounts (when not reserved),
-//! slashing an account balance, account removal, rewards,
-//! lookup of an index to reclaim an account (when not balance not reserved),
-//! increasing total stake.
+//! An index is a short form of an address. This module handles allocation
+//! of indices for a newly created accounts.
 
 #![cfg_attr(not(feature = "std"), no_std)]
 
+// We need these `extern crate` to be placed here otherwise there will be errors.
+// TODO: https://github.com/paritytech/substrate/issues/1509
 #[macro_use]
 extern crate srml_support as runtime_support;
-
-extern crate sr_std as rstd;
-
-#[macro_use]
 extern crate parity_codec_derive;
-
 extern crate parity_codec as codec;
-extern crate sr_primitives as primitives;
-extern crate srml_system as system;
-
-#[cfg(test)]
-#[macro_use]
-extern crate ref_thread_local;
-#[cfg(test)]
-extern crate sr_io as runtime_io;
-#[cfg(test)]
-extern crate substrate_primitives;
 
 use rstd::{prelude::*, result, marker::PhantomData};
 use codec::{Encode, Decode, Codec, Input, Output};
 use runtime_support::{StorageValue, StorageMap, Parameter};
 use primitives::traits::{One, SimpleArithmetic, As, StaticLookup, Member};
-use address::Address as RawAddress;
 use system::{IsDeadAccount, OnNewAccount};
 
+use self::address::Address as RawAddress;
+
 mod mock;
 
 pub mod address;
@@ -104,7 +87,10 @@ decl_event!(
 		<T as system::Trait>::AccountId,
 		<T as Trait>::AccountIndex
 	{
-		/// A new account was created.
+		/// A new account index was assigned.
+		///
+		/// This event is not triggered when an existing index is reassigned
+		/// to another `AccountId`.
 		NewAccountIndex(AccountId, AccountIndex),
 	}
 );
@@ -138,7 +124,7 @@ impl<T: Trait> Module<T> {
 		let enum_set_size = Self::enum_set_size();
 		let set = Self::enum_set(index / enum_set_size);
 		let i: usize = (index % enum_set_size).as_();
-		set.get(i).map(|x| x.clone())
+		set.get(i).cloned()
 	}
 
 	/// `true` if the account `index` is ready for reclaim.

substrate/srml/indices/src/mock.rs

@@ -19,13 +19,12 @@
 #![cfg(test)]
 
 use std::collections::HashSet;
-use ref_thread_local::RefThreadLocal;
+use ref_thread_local::{ref_thread_local, RefThreadLocal};
 use primitives::BuildStorage;
 use primitives::testing::{Digest, DigestItem, Header};
 use substrate_primitives::{H256, Blake2Hasher};
-use runtime_io;
-use {GenesisConfig, Module, Trait, system};
-use super::{IsDeadAccount, OnNewAccount, ResolveHint};
+use {runtime_io, system};
+use crate::{GenesisConfig, Module, Trait, IsDeadAccount, OnNewAccount, ResolveHint};
 
 impl_outer_origin!{
 	pub enum Origin for Runtime {}

substrate/srml/indices/src/tests.rs

@@ -19,7 +19,7 @@
 #![cfg(test)]
 
 use super::*;
-use mock::{Indices, new_test_ext, make_account, kill_account, TestIsDeadAccount};
+use crate::mock::{Indices, new_test_ext, make_account, kill_account, TestIsDeadAccount};
 use runtime_io::with_externalities;
 
 #[test]