sp-std -> core (#3199)

First in a series of PRs that reduces our use of sp-std with a view to
deprecating it.

This is just looking at /substrate and moving some of the references
from `sp-std` to `core`.
These particular changes should be uncontroversial.

Where macros are used `::core` should be used to remove any ambiguity.

part of https://github.com/paritytech/polkadot-sdk/issues/2101

substrate/frame/support/src/tests/mod.rs

@@ -171,7 +171,7 @@ pub mod frame_system {
 		pub data: Vec<(u32, u64)>,
 		pub test_config: Vec<(u32, u32, u64)>,
 		#[serde(skip)]
-		pub _config: sp_std::marker::PhantomData<T>,
+		pub _config: core::marker::PhantomData<T>,
 	}
 
 	impl<T: Config> Default for GenesisConfig<T> {

substrate/frame/support/src/traits/dispatch.rs

@@ -19,11 +19,11 @@
 
 use crate::dispatch::{DispatchResultWithPostInfo, Parameter, RawOrigin};
 use codec::MaxEncodedLen;
+use core::{cmp::Ordering, marker::PhantomData};
 use sp_runtime::{
 	traits::{BadOrigin, Get, Member, Morph, TryMorph},
 	Either,
 };
-use sp_std::{cmp::Ordering, marker::PhantomData};
 
 use super::misc;
 
@@ -85,7 +85,7 @@ pub trait EnsureOrigin<OuterOrigin> {
 /// ```rust
 /// # use frame_support::traits::{EnsureOriginEqualOrHigherPrivilege, PrivilegeCmp, EnsureOrigin as _};
 /// # use sp_runtime::traits::{parameter_types, Get};
-/// # use sp_std::cmp::Ordering;
+/// # use core::cmp::Ordering;
 ///
 /// #[derive(Eq, PartialEq, Debug)]
 /// pub enum Origin {
@@ -124,7 +124,7 @@ pub trait EnsureOrigin<OuterOrigin> {
 /// assert!(EnsureOrigin::ensure_origin(Origin::NormalUser).is_err());
 /// ```
 pub struct EnsureOriginEqualOrHigherPrivilege<Origin, PrivilegeCmp>(
-	sp_std::marker::PhantomData<(Origin, PrivilegeCmp)>,
+	core::marker::PhantomData<(Origin, PrivilegeCmp)>,
 );
 
 impl<OuterOrigin, Origin, PrivilegeCmp> EnsureOrigin<OuterOrigin>
@@ -218,7 +218,7 @@ macro_rules! impl_ensure_origin_with_arg_ignoring_arg {
 }
 
 /// [`EnsureOrigin`] implementation that always fails.
-pub struct NeverEnsureOrigin<Success>(sp_std::marker::PhantomData<Success>);
+pub struct NeverEnsureOrigin<Success>(core::marker::PhantomData<Success>);
 impl<OO, Success> EnsureOrigin<OO> for NeverEnsureOrigin<Success> {
 	type Success = Success;
 	fn try_origin(o: OO) -> Result<Success, OO> {
@@ -235,7 +235,7 @@ impl_ensure_origin_with_arg_ignoring_arg! {
 	{}
 }
 
-pub struct AsEnsureOriginWithArg<EO>(sp_std::marker::PhantomData<EO>);
+pub struct AsEnsureOriginWithArg<EO>(core::marker::PhantomData<EO>);
 impl<OuterOrigin, Argument, EO: EnsureOrigin<OuterOrigin>>
 	EnsureOriginWithArg<OuterOrigin, Argument> for AsEnsureOriginWithArg<EO>
 {
@@ -353,7 +353,7 @@ impl<
 /// Origin check will pass if `L` or `R` origin check passes. `L` is tested first.
 ///
 /// Successful origin is derived from the left side.
-pub struct EitherOfDiverse<L, R>(sp_std::marker::PhantomData<(L, R)>);
+pub struct EitherOfDiverse<L, R>(core::marker::PhantomData<(L, R)>);
 impl<OuterOrigin, L: EnsureOrigin<OuterOrigin>, R: EnsureOrigin<OuterOrigin>>
 	EnsureOrigin<OuterOrigin> for EitherOfDiverse<L, R>
 {
@@ -402,7 +402,7 @@ pub type EnsureOneOf<L, R> = EitherOfDiverse<L, R>;
 /// Origin check will pass if `L` or `R` origin check passes. `L` is tested first.
 ///
 /// Successful origin is derived from the left side.
-pub struct EitherOf<L, R>(sp_std::marker::PhantomData<(L, R)>);
+pub struct EitherOf<L, R>(core::marker::PhantomData<(L, R)>);
 impl<
 		OuterOrigin,
 		L: EnsureOrigin<OuterOrigin>,

substrate/frame/support/src/traits/error.rs

@@ -17,7 +17,7 @@
 
 //! Traits for describing and constraining pallet error types.
 use codec::{Compact, Decode, Encode};
-use sp_std::marker::PhantomData;
+use core::marker::PhantomData;
 
 /// Trait indicating that the implementing type is going to be included as a field in a variant of
 /// the `#[pallet::error]` enum type.

substrate/frame/support/src/traits/stored_map.rs

@@ -81,7 +81,7 @@ pub trait StoredMap<K, T: Default> {
 /// be the default value), or where the account is being removed or reset back to the default value
 /// where previously it did exist (though may have been in a default state). This works well with
 /// system module's `CallOnCreatedAccount` and `CallKillAccount`.
-pub struct StorageMapShim<S, K, T>(sp_std::marker::PhantomData<(S, K, T)>);
+pub struct StorageMapShim<S, K, T>(core::marker::PhantomData<(S, K, T)>);
 impl<S: StorageMap<K, T, Query = T>, K: FullCodec, T: FullCodec + Default> StoredMap<K, T>
 	for StorageMapShim<S, K, T>
 {

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

@@ -211,7 +211,7 @@ pub trait Currency<AccountId> {
 
 /// A non-const `Get` implementation parameterised by a `Currency` impl which provides the result
 /// of `total_issuance`.
-pub struct TotalIssuanceOf<C: Currency<A>, A>(sp_std::marker::PhantomData<(C, A)>);
+pub struct TotalIssuanceOf<C: Currency<A>, A>(core::marker::PhantomData<(C, A)>);
 impl<C: Currency<A>, A> Get<C::Balance> for TotalIssuanceOf<C, A> {
 	fn get() -> C::Balance {
 		C::total_issuance()
@@ -220,7 +220,7 @@ impl<C: Currency<A>, A> Get<C::Balance> for TotalIssuanceOf<C, A> {
 
 /// A non-const `Get` implementation parameterised by a `Currency` impl which provides the result
 /// of `active_issuance`.
-pub struct ActiveIssuanceOf<C: Currency<A>, A>(sp_std::marker::PhantomData<(C, A)>);
+pub struct ActiveIssuanceOf<C: Currency<A>, A>(core::marker::PhantomData<(C, A)>);
 impl<C: Currency<A>, A> Get<C::Balance> for ActiveIssuanceOf<C, A> {
 	fn get() -> C::Balance {
 		C::active_issuance()

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

@@ -19,8 +19,8 @@
 //! with unbalanced operations.
 
 use crate::traits::misc::{SameOrOther, TryDrop};
+use core::ops::Div;
 use sp_runtime::traits::Saturating;
-use sp_std::ops::Div;
 
 mod on_unbalanced;
 mod signed_imbalance;