sp-std removal from substrate/primitives (#3274)

This PR removes sp-std crate from substrate/primitives sub-directories.

For now crates that have `pub use` of sp-std or export macros that would
necessitate users of the macros to `extern crate alloc` have been
excluded from this PR.

There should be no breaking changes in this PR.

---------

Co-authored-by: Koute <koute@users.noreply.github.com>

substrate/primitives/state-machine/src/overlayed_changes/changeset.rs

@@ -20,16 +20,14 @@
 use super::{Extrinsics, StorageKey, StorageValue};
 
 #[cfg(not(feature = "std"))]
-use sp_std::collections::btree_set::BTreeSet as Set;
+use alloc::collections::btree_set::BTreeSet as Set;
 #[cfg(feature = "std")]
 use std::collections::HashSet as Set;
 
 use crate::warn;
+use alloc::collections::{btree_map::BTreeMap, btree_set::BTreeSet};
+use core::hash::Hash;
 use smallvec::SmallVec;
-use sp_std::{
-	collections::{btree_map::BTreeMap, btree_set::BTreeSet},
-	hash::Hash,
-};
 
 const PROOF_OVERLAY_NON_EMPTY: &str = "\
 	An OverlayValue is always created with at least one transaction and dropped as soon
@@ -225,7 +223,7 @@ impl<K: Ord + Hash + Clone, V> OverlayedMap<K, V> {
 	/// This changeset might be created when there are already open transactions.
 	/// We need to catch up here so that the child is at the same transaction depth.
 	pub fn spawn_child(&self) -> Self {
-		use sp_std::iter::repeat;
+		use core::iter::repeat;
 		Self {
 			changes: Default::default(),
 			dirty_keys: repeat(Set::new()).take(self.transaction_depth()).collect(),
@@ -242,7 +240,7 @@ impl<K: Ord + Hash + Clone, V> OverlayedMap<K, V> {
 	/// Get an optional reference to the value stored for the specified key.
 	pub fn get<Q>(&self, key: &Q) -> Option<&OverlayedEntry<V>>
 	where
-		K: sp_std::borrow::Borrow<Q>,
+		K: core::borrow::Borrow<Q>,
 		Q: Ord + ?Sized,
 	{
 		self.changes.get(key)
@@ -448,7 +446,7 @@ impl OverlayedChangeSet {
 
 	/// Get the iterator over all changes that follow the supplied `key`.
 	pub fn changes_after(&self, key: &[u8]) -> impl Iterator<Item = (&[u8], &OverlayedValue)> {
-		use sp_std::ops::Bound;
+		use core::ops::Bound;
 		let range = (Bound::Excluded(key), Bound::Unbounded);
 		self.changes.range::<[u8], _>(range).map(|(k, v)| (k.as_slice(), v))
 	}

substrate/primitives/state-machine/src/overlayed_changes/mod.rs

@@ -22,6 +22,7 @@ mod offchain;
 
 use self::changeset::OverlayedChangeSet;
 use crate::{backend::Backend, stats::StateMachineStats, BackendTransaction, DefaultError};
+use alloc::{collections::btree_set::BTreeSet, vec::Vec};
 use codec::{Decode, Encode};
 use hash_db::Hasher;
 pub use offchain::OffchainOverlayedChanges;
@@ -31,12 +32,13 @@ use sp_core::{
 };
 #[cfg(feature = "std")]
 use sp_externalities::{Extension, Extensions};
-#[cfg(not(feature = "std"))]
-use sp_std::collections::btree_map::BTreeMap as Map;
-use sp_std::{collections::btree_set::BTreeSet, vec::Vec};
 use sp_trie::{empty_child_trie_root, LayoutV1};
+
+#[cfg(not(feature = "std"))]
+use alloc::collections::btree_map::BTreeMap as Map;
 #[cfg(feature = "std")]
 use std::collections::{hash_map::Entry as MapEntry, HashMap as Map};
+
 #[cfg(feature = "std")]
 use std::{
 	any::{Any, TypeId},
@@ -136,7 +138,7 @@ impl<H: Hasher> Clone for OverlayedChanges<H> {
 	}
 }
 
-impl<H: Hasher> sp_std::fmt::Debug for OverlayedChanges<H> {
+impl<H: Hasher> core::fmt::Debug for OverlayedChanges<H> {
 	fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
 		f.debug_struct("OverlayedChanges")
 			.field("top", &self.top)
@@ -259,7 +261,7 @@ impl<H: Hasher> Clone for StorageTransactionCache<H> {
 	}
 }
 
-impl<H: Hasher> sp_std::fmt::Debug for StorageTransactionCache<H> {
+impl<H: Hasher> core::fmt::Debug for StorageTransactionCache<H> {
 	fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
 		let mut debug = f.debug_struct("StorageTransactionCache");
 
@@ -572,7 +574,7 @@ impl<H: Hasher> OverlayedChanges<H> {
 			},
 		};
 
-		use sp_std::mem::take;
+		use core::mem::take;
 		let main_storage_changes = take(&mut self.top).drain_commited();
 		let child_storage_changes = take(&mut self.children)
 			.into_iter()
@@ -777,7 +779,7 @@ where
 	K: Ord,
 	F: FnMut(&K, &mut V) -> bool,
 {
-	let old = sp_std::mem::replace(map, Map::default());
+	let old = core::mem::replace(map, Map::default());
 	for (k, mut v) in old.into_iter() {
 		if f(&k, &mut v) {
 			map.insert(k, v);

substrate/primitives/state-machine/src/overlayed_changes/offchain.rs

@@ -18,8 +18,8 @@
 //! Overlayed changes for offchain indexing.
 
 use super::changeset::OverlayedMap;
+use alloc::vec::Vec;
 use sp_core::offchain::OffchainOverlayedChange;
-use sp_std::prelude::Vec;
 
 /// In-memory storage for offchain workers recoding changes for the actual offchain storage
 /// implementation.
@@ -48,7 +48,7 @@ impl OffchainOverlayedChanges {
 
 	/// Drain all elements of changeset.
 	pub fn drain(&mut self) -> impl Iterator<Item = OffchainOverlayedChangesItemOwned> {
-		sp_std::mem::take(self).into_iter()
+		core::mem::take(self).into_iter()
 	}
 
 	/// Remove a key and its associated value from the offchain database.