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>

Cargo.lock

@@ -18402,7 +18402,6 @@ dependencies = [
  "scale-info",
  "serde",
  "sp-crypto-hashing",
- "sp-std 14.0.0",
  "static_assertions",
 ]
 
@@ -18444,7 +18443,6 @@ dependencies = [
  "sp-api",
  "sp-application-crypto",
  "sp-runtime",
- "sp-std 14.0.0",
 ]
 
 [[package]]
@@ -18454,7 +18452,6 @@ dependencies = [
  "sp-api",
  "sp-inherents",
  "sp-runtime",
- "sp-std 14.0.0",
 ]
 
 [[package]]
@@ -18501,7 +18498,6 @@ dependencies = [
  "sp-consensus-slots",
  "sp-inherents",
  "sp-runtime",
- "sp-std 14.0.0",
  "sp-timestamp",
 ]
 
@@ -18519,7 +18515,6 @@ dependencies = [
  "sp-core",
  "sp-inherents",
  "sp-runtime",
- "sp-std 14.0.0",
  "sp-timestamp",
 ]
 
@@ -18540,7 +18535,6 @@ dependencies = [
  "sp-keystore",
  "sp-mmr-primitives",
  "sp-runtime",
- "sp-std 14.0.0",
  "strum 0.24.1",
  "w3f-bls",
 ]
@@ -18559,7 +18553,6 @@ dependencies = [
  "sp-core",
  "sp-keystore",
  "sp-runtime",
- "sp-std 14.0.0",
 ]
 
 [[package]]
@@ -18570,7 +18563,6 @@ dependencies = [
  "sp-api",
  "sp-core",
  "sp-runtime",
- "sp-std 14.0.0",
 ]
 
 [[package]]
@@ -18585,7 +18577,6 @@ dependencies = [
  "sp-consensus-slots",
  "sp-core",
  "sp-runtime",
- "sp-std 14.0.0",
 ]
 
 [[package]]
@@ -18595,7 +18586,6 @@ dependencies = [
  "parity-scale-codec",
  "scale-info",
  "serde",
- "sp-std 14.0.0",
  "sp-timestamp",
 ]
 
@@ -18711,7 +18701,6 @@ dependencies = [
  "ark-ed-on-bls12-381-bandersnatch-ext",
  "ark-scale 0.0.12",
  "sp-runtime-interface 24.0.0",
- "sp-std 14.0.0",
 ]
 
 [[package]]
@@ -18781,7 +18770,6 @@ version = "0.25.0"
 dependencies = [
  "environmental",
  "parity-scale-codec",
- "sp-std 14.0.0",
  "sp-storage 19.0.0",
 ]
 
@@ -18792,7 +18780,6 @@ dependencies = [
  "serde_json",
  "sp-api",
  "sp-runtime",
- "sp-std 14.0.0",
 ]
 
 [[package]]
@@ -18805,7 +18792,6 @@ dependencies = [
  "parity-scale-codec",
  "scale-info",
  "sp-runtime",
- "sp-std 14.0.0",
  "thiserror",
 ]
 
@@ -18870,7 +18856,6 @@ dependencies = [
  "frame-metadata",
  "parity-scale-codec",
  "scale-info",
- "sp-std 14.0.0",
 ]
 
 [[package]]
@@ -18881,7 +18866,6 @@ dependencies = [
  "scale-info",
  "sp-api",
  "sp-application-crypto",
- "sp-std 14.0.0",
 ]
 
 [[package]]
@@ -18898,7 +18882,6 @@ dependencies = [
  "sp-core",
  "sp-debug-derive 14.0.0",
  "sp-runtime",
- "sp-std 14.0.0",
  "thiserror",
 ]
 
@@ -18913,7 +18896,6 @@ dependencies = [
  "sp-arithmetic",
  "sp-core",
  "sp-runtime",
- "sp-std 14.0.0",
  "substrate-test-utils",
 ]
 
@@ -19100,7 +19082,6 @@ dependencies = [
  "sp-keystore",
  "sp-runtime",
  "sp-staking",
- "sp-std 14.0.0",
 ]
 
 [[package]]
@@ -19113,7 +19094,6 @@ dependencies = [
  "serde",
  "sp-core",
  "sp-runtime",
- "sp-std 14.0.0",
 ]
 
 [[package]]
@@ -19133,7 +19113,6 @@ dependencies = [
  "sp-externalities 0.25.0",
  "sp-panic-handler",
  "sp-runtime",
- "sp-std 14.0.0",
  "sp-trie",
  "thiserror",
  "tracing",
@@ -19159,7 +19138,6 @@ dependencies = [
  "sp-externalities 0.25.0",
  "sp-runtime",
  "sp-runtime-interface 24.0.0",
- "sp-std 14.0.0",
  "thiserror",
  "x25519-dalek 2.0.0",
 ]
@@ -19195,7 +19173,6 @@ dependencies = [
  "ref-cast",
  "serde",
  "sp-debug-derive 14.0.0",
- "sp-std 14.0.0",
 ]
 
 [[package]]
@@ -19208,7 +19185,6 @@ dependencies = [
  "sp-application-crypto",
  "sp-core",
  "sp-runtime",
- "sp-std 14.0.0",
 ]
 
 [[package]]
@@ -19219,7 +19195,6 @@ dependencies = [
  "parity-scale-codec",
  "sp-inherents",
  "sp-runtime",
- "sp-std 14.0.0",
  "thiserror",
 ]
 
@@ -19240,7 +19215,6 @@ name = "sp-tracing"
 version = "16.0.0"
 dependencies = [
  "parity-scale-codec",
- "sp-std 14.0.0",
  "tracing",
  "tracing-core",
  "tracing-subscriber 0.2.25",
@@ -19264,7 +19238,6 @@ dependencies = [
  "sp-core",
  "sp-inherents",
  "sp-runtime",
- "sp-std 14.0.0",
  "sp-trie",
 ]
 
@@ -19287,7 +19260,6 @@ dependencies = [
  "sp-core",
  "sp-externalities 0.25.0",
  "sp-runtime",
- "sp-std 14.0.0",
  "thiserror",
  "tracing",
  "trie-bench",
@@ -19344,7 +19316,6 @@ dependencies = [
  "impl-trait-for-tuples",
  "log",
  "parity-scale-codec",
- "sp-std 14.0.0",
  "wasmtime",
 ]
 
@@ -19360,7 +19331,6 @@ dependencies = [
  "smallvec",
  "sp-arithmetic",
  "sp-debug-derive 14.0.0",
- "sp-std 14.0.0",
 ]
 
 [[package]]
@@ -19971,7 +19941,6 @@ dependencies = [
  "sp-runtime",
  "sp-session",
  "sp-state-machine",
- "sp-std 14.0.0",
  "sp-tracing 16.0.0",
  "sp-transaction-pool",
  "sp-trie",

substrate/primitives/arithmetic/Cargo.toml

@@ -26,7 +26,6 @@ num-traits = { version = "0.2.17", default-features = false }
 scale-info = { version = "2.10.0", default-features = false, features = ["derive"] }
 serde = { features = ["alloc", "derive"], optional = true, workspace = true }
 static_assertions = "1.1.0"
-sp-std = { path = "../std", default-features = false }
 
 [dev-dependencies]
 criterion = "0.4.0"
@@ -42,7 +41,6 @@ std = [
 	"scale-info/std",
 	"serde/std",
 	"sp-crypto-hashing/std",
-	"sp-std/std",
 ]
 # Serde support without relying on std features.
 serde = ["dep:serde", "scale-info/serde"]

substrate/primitives/arithmetic/src/biguint.rs

@@ -17,9 +17,10 @@
 
 //! Infinite precision unsigned integer for substrate runtime.
 
+use alloc::{vec, vec::Vec};
 use codec::{Decode, Encode};
+use core::{cell::RefCell, cmp::Ordering, ops};
 use num_traits::{One, Zero};
-use sp_std::{cell::RefCell, cmp::Ordering, ops, prelude::*, vec};
 
 // A sensible value for this would be half of the dword size of the host machine. Since the
 // runtime is compiled to 32bit webassembly, using 32 and 64 for single and double respectively
@@ -35,7 +36,7 @@ const SHIFT: usize = 32;
 const B: Double = Single::max_value() as Double + 1;
 
 static_assertions::const_assert!(
-	sp_std::mem::size_of::<Double>() - sp_std::mem::size_of::<Single>() == SHIFT / 8
+	core::mem::size_of::<Double>() - core::mem::size_of::<Single>() == SHIFT / 8
 );
 
 /// Splits a [`Double`] limb number into a tuple of two [`Single`] limb numbers.
@@ -438,9 +439,9 @@ impl BigUint {
 	}
 }
 
-impl sp_std::fmt::Debug for BigUint {
+impl core::fmt::Debug for BigUint {
 	#[cfg(feature = "std")]
-	fn fmt(&self, f: &mut sp_std::fmt::Formatter<'_>) -> sp_std::fmt::Result {
+	fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
 		write!(
 			f,
 			"BigUint {{ {:?} ({:?})}}",
@@ -450,7 +451,7 @@ impl sp_std::fmt::Debug for BigUint {
 	}
 
 	#[cfg(not(feature = "std"))]
-	fn fmt(&self, _: &mut sp_std::fmt::Formatter<'_>) -> sp_std::fmt::Result {
+	fn fmt(&self, _: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
 		Ok(())
 	}
 }

substrate/primitives/arithmetic/src/fixed_point.rs

@@ -26,17 +26,16 @@ use crate::{
 	PerThing, Perbill, Rounding, SignedRounding,
 };
 use codec::{CompactAs, Decode, Encode};
-use sp_std::{
+use core::{
 	fmt::Debug,
 	ops::{self, Add, Div, Mul, Sub},
-	prelude::*,
 };
 
 #[cfg(feature = "serde")]
 use serde::{de, Deserialize, Deserializer, Serialize, Serializer};
 
 #[cfg(all(not(feature = "std"), feature = "serde"))]
-use sp_std::alloc::string::{String, ToString};
+use alloc::string::{String, ToString};
 
 /// Integer types that can be used to interact with `FixedPointNumber` implementations.
 pub trait FixedPointOperand:
@@ -899,9 +898,9 @@ macro_rules! implement_fixed {
 			}
 		}
 
-		impl sp_std::fmt::Debug for $name {
+		impl ::core::fmt::Debug for $name {
 			#[cfg(feature = "std")]
-			fn fmt(&self, f: &mut sp_std::fmt::Formatter) -> sp_std::fmt::Result {
+			fn fmt(&self, f: &mut ::core::fmt::Formatter) -> ::core::fmt::Result {
 				let integral = {
 					let int = self.0 / Self::accuracy();
 					let signum_for_zero = if int == 0 && self.is_negative() { "-" } else { "" };
@@ -917,7 +916,7 @@ macro_rules! implement_fixed {
 			}
 
 			#[cfg(not(feature = "std"))]
-			fn fmt(&self, _: &mut sp_std::fmt::Formatter) -> sp_std::fmt::Result {
+			fn fmt(&self, _: &mut ::core::fmt::Formatter) -> ::core::fmt::Result {
 				Ok(())
 			}
 		}
@@ -933,13 +932,13 @@ macro_rules! implement_fixed {
 			}
 		}
 
-		impl sp_std::fmt::Display for $name {
+		impl ::core::fmt::Display for $name {
-			fn fmt(&self, f: &mut sp_std::fmt::Formatter) -> sp_std::fmt::Result {
+			fn fmt(&self, f: &mut ::core::fmt::Formatter) -> ::core::fmt::Result {
 				write!(f, "{}", self.0)
 			}
 		}
 
-		impl sp_std::str::FromStr for $name {
+		impl ::core::str::FromStr for $name {
 			type Err = &'static str;
 
 			fn from_str(s: &str) -> Result<Self, Self::Err> {
@@ -969,7 +968,7 @@ macro_rules! implement_fixed {
 			where
 				D: Deserializer<'de>,
 			{
-				use sp_std::str::FromStr;
+				use ::core::str::FromStr;
 				let s = String::deserialize(deserializer)?;
 				$name::from_str(&s).map_err(de::Error::custom)
 			}

substrate/primitives/arithmetic/src/lib.rs

@@ -19,6 +19,8 @@
 
 #![cfg_attr(not(feature = "std"), no_std)]
 
+extern crate alloc;
+
 /// Copied from `sp-runtime` and documented there.
 #[macro_export]
 macro_rules! assert_eq_error_rate {
@@ -49,7 +51,8 @@ pub use per_things::{
 };
 pub use rational::{MultiplyRational, Rational128, RationalInfinite};
 
-use sp_std::{cmp::Ordering, fmt::Debug, prelude::*};
+use alloc::vec::Vec;
+use core::{cmp::Ordering, fmt::Debug};
 use traits::{BaseArithmetic, One, SaturatedConversion, Unsigned, Zero};
 
 use codec::{Decode, Encode, MaxEncodedLen};
@@ -429,7 +432,7 @@ mod normalize_tests {
 mod threshold_compare_tests {
 	use super::*;
 	use crate::traits::Saturating;
-	use sp_std::cmp::Ordering;
+	use core::cmp::Ordering;
 
 	#[test]
 	fn epsilon_ord_works() {

substrate/primitives/arithmetic/src/per_things.rs

@@ -23,12 +23,11 @@ use crate::traits::{
 	Saturating, UniqueSaturatedInto, Unsigned, Zero,
 };
 use codec::{CompactAs, Encode};
-use num_traits::{Pow, SaturatingAdd, SaturatingSub};
+use core::{
-use sp_std::{
 	fmt, ops,
 	ops::{Add, Sub},
-	prelude::*,
 };
+use num_traits::{Pow, SaturatingAdd, SaturatingSub};
 
 /// Get the inner type of a `PerThing`.
 pub type InnerOf<P> = <P as PerThing>::Inner;
@@ -414,7 +413,7 @@ pub trait PerThing:
 }
 
 /// The rounding method to use for unsigned quantities.
-#[derive(Copy, Clone, sp_std::fmt::Debug)]
+#[derive(Copy, Clone, core::fmt::Debug)]
 pub enum Rounding {
 	// Towards infinity.
 	Up,
@@ -427,7 +426,7 @@ pub enum Rounding {
 }
 
 /// The rounding method to use.
-#[derive(Copy, Clone, sp_std::fmt::Debug)]
+#[derive(Copy, Clone, core::fmt::Debug)]
 pub enum SignedRounding {
 	// Towards positive infinity.
 	High,
@@ -580,8 +579,8 @@ macro_rules! implement_per_thing {
 		}
 
 		#[cfg(feature = "std")]
-		impl sp_std::fmt::Debug for $name {
+		impl core::fmt::Debug for $name {
-			fn fmt(&self, fmt: &mut std::fmt::Formatter) -> std::fmt::Result {
+			fn fmt(&self, fmt: &mut core::fmt::Formatter) -> core::fmt::Result {
 				if $max == <$type>::max_value() {
 					// Not a power of ten: show as N/D and approx %
 					let pc = (self.0 as f64) / (self.0 as f64) * 100f64;
@@ -606,8 +605,8 @@ macro_rules! implement_per_thing {
 		}
 
 		#[cfg(not(feature = "std"))]
-		impl sp_std::fmt::Debug for $name {
+		impl core::fmt::Debug for $name {
-			fn fmt(&self, fmt: &mut sp_std::fmt::Formatter) -> sp_std::fmt::Result {
+			fn fmt(&self, fmt: &mut core::fmt::Formatter) -> core::fmt::Result {
 				if $max == <$type>::max_value() {
 					// Not a power of ten: show as N/D and approx %
 					write!(fmt, "{}/{}", self.0, $max)

substrate/primitives/arithmetic/src/rational.rs

@@ -16,8 +16,8 @@
 // limitations under the License.
 
 use crate::{biguint::BigUint, helpers_128bit, Rounding};
+use core::cmp::Ordering;
 use num_traits::{Bounded, One, Zero};
-use sp_std::{cmp::Ordering, prelude::*};
 
 /// A wrapper for any rational number with infinitely large numerator and denominator.
 ///
@@ -92,15 +92,15 @@ impl From<Rational128> for RationalInfinite {
 pub struct Rational128(u128, u128);
 
 #[cfg(feature = "std")]
-impl sp_std::fmt::Debug for Rational128 {
+impl core::fmt::Debug for Rational128 {
-	fn fmt(&self, f: &mut sp_std::fmt::Formatter<'_>) -> sp_std::fmt::Result {
+	fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
 		write!(f, "Rational128({} / {} ≈ {:.8})", self.0, self.1, self.0 as f64 / self.1 as f64)
 	}
 }
 
 #[cfg(not(feature = "std"))]
-impl sp_std::fmt::Debug for Rational128 {
+impl core::fmt::Debug for Rational128 {
-	fn fmt(&self, f: &mut sp_std::fmt::Formatter<'_>) -> sp_std::fmt::Result {
+	fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
 		write!(f, "Rational128({} / {})", self.0, self.1)
 	}
 }

substrate/primitives/authority-discovery/Cargo.toml

@@ -21,7 +21,6 @@ scale-info = { version = "2.10.0", default-features = false, features = ["derive
 sp-api = { path = "../api", default-features = false }
 sp-application-crypto = { path = "../application-crypto", default-features = false }
 sp-runtime = { path = "../runtime", default-features = false }
-sp-std = { path = "../std", default-features = false }
 
 [features]
 default = ["std"]
@@ -31,7 +30,6 @@ std = [
 	"sp-api/std",
 	"sp-application-crypto/std",
 	"sp-runtime/std",
-	"sp-std/std",
 ]
 serde = [
 	"scale-info/serde",

substrate/primitives/authority-discovery/src/lib.rs

@@ -19,7 +19,9 @@
 
 #![cfg_attr(not(feature = "std"), no_std)]
 
-use sp_std::vec::Vec;
+extern crate alloc;
+
+use alloc::vec::Vec;
 
 mod app {
 	use sp_application_crypto::{app_crypto, key_types::AUTHORITY_DISCOVERY, sr25519};

substrate/primitives/block-builder/Cargo.toml

@@ -19,8 +19,7 @@ targets = ["x86_64-unknown-linux-gnu"]
 sp-api = { path = "../api", default-features = false }
 sp-inherents = { path = "../inherents", default-features = false }
 sp-runtime = { path = "../runtime", default-features = false }
-sp-std = { path = "../std", default-features = false }
 
 [features]
 default = ["std"]
-std = ["sp-api/std", "sp-inherents/std", "sp-runtime/std", "sp-std/std"]
+std = ["sp-api/std", "sp-inherents/std", "sp-runtime/std"]

substrate/primitives/block-builder/src/lib.rs

@@ -19,6 +19,8 @@
 
 #![cfg_attr(not(feature = "std"), no_std)]
 
+extern crate alloc;
+
 use sp_inherents::{CheckInherentsResult, InherentData};
 use sp_runtime::{traits::Block as BlockT, ApplyExtrinsicResult};
 
@@ -44,7 +46,7 @@ sp_api::decl_runtime_apis! {
 		/// Generate inherent extrinsics. The inherent data will vary from chain to chain.
 		fn inherent_extrinsics(
 			inherent: InherentData,
-		) -> sp_std::vec::Vec<<Block as BlockT>::Extrinsic>;
+		) -> alloc::vec::Vec<<Block as BlockT>::Extrinsic>;
 
 		/// Check that the inherents are valid. The inherent data will vary from chain to chain.
 		fn check_inherents(block: Block, data: InherentData) -> CheckInherentsResult;

substrate/primitives/consensus/aura/Cargo.toml

@@ -24,7 +24,6 @@ sp-application-crypto = { path = "../../application-crypto", default-features =
 sp-consensus-slots = { path = "../slots", default-features = false }
 sp-inherents = { path = "../../inherents", default-features = false }
 sp-runtime = { path = "../../runtime", default-features = false }
-sp-std = { path = "../../std", default-features = false }
 sp-timestamp = { path = "../../timestamp", default-features = false }
 
 [features]
@@ -38,7 +37,6 @@ std = [
 	"sp-consensus-slots/std",
 	"sp-inherents/std",
 	"sp-runtime/std",
-	"sp-std/std",
 	"sp-timestamp/std",
 ]
 

substrate/primitives/consensus/aura/src/lib.rs

@@ -19,9 +19,11 @@
 
 #![cfg_attr(not(feature = "std"), no_std)]
 
+extern crate alloc;
+
+use alloc::vec::Vec;
 use codec::{Codec, Decode, Encode};
 use sp_runtime::ConsensusEngineId;
-use sp_std::vec::Vec;
 
 pub mod digests;
 pub mod inherents;

substrate/primitives/consensus/babe/Cargo.toml

@@ -26,7 +26,6 @@ sp-consensus-slots = { path = "../slots", default-features = false }
 sp-core = { path = "../../core", default-features = false }
 sp-inherents = { path = "../../inherents", default-features = false }
 sp-runtime = { path = "../../runtime", default-features = false }
-sp-std = { path = "../../std", default-features = false }
 sp-timestamp = { path = "../../timestamp", optional = true }
 
 [features]
@@ -42,7 +41,6 @@ std = [
 	"sp-core/std",
 	"sp-inherents/std",
 	"sp-runtime/std",
-	"sp-std/std",
 	"sp-timestamp/std",
 ]
 

substrate/primitives/consensus/babe/src/digests.rs

@@ -22,9 +22,10 @@ use super::{
 	BabeEpochConfiguration, Randomness, Slot, BABE_ENGINE_ID,
 };
 
+#[cfg(not(feature = "std"))]
+use alloc::vec::Vec;
 use sp_core::sr25519::vrf::VrfSignature;
 use sp_runtime::{DigestItem, RuntimeDebug};
-use sp_std::vec::Vec;
 
 use codec::{Decode, Encode, MaxEncodedLen};
 use scale_info::TypeInfo;

substrate/primitives/consensus/babe/src/lib.rs

@@ -20,15 +20,18 @@
 #![forbid(unsafe_code, missing_docs, unused_variables, unused_imports)]
 #![cfg_attr(not(feature = "std"), no_std)]
 
+extern crate alloc;
+
 pub mod digests;
 pub mod inherents;
 
+#[cfg(not(feature = "std"))]
+use alloc::vec::Vec;
 use codec::{Decode, Encode, MaxEncodedLen};
 use scale_info::TypeInfo;
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
 use sp_runtime::{traits::Header, ConsensusEngineId, RuntimeDebug};
-use sp_std::vec::Vec;
 
 use crate::digests::{NextConfigDescriptor, NextEpochDescriptor};
 

substrate/primitives/consensus/beefy/Cargo.toml

@@ -26,7 +26,6 @@ sp-io = { path = "../../io", default-features = false }
 sp-mmr-primitives = { path = "../../merkle-mountain-range", default-features = false }
 sp-runtime = { path = "../../runtime", default-features = false }
 sp-keystore = { path = "../../keystore", default-features = false }
-sp-std = { path = "../../std", default-features = false }
 strum = { version = "0.24.1", features = ["derive"], default-features = false }
 lazy_static = { version = "1.4.0", optional = true }
 
@@ -49,7 +48,6 @@ std = [
 	"sp-keystore/std",
 	"sp-mmr-primitives/std",
 	"sp-runtime/std",
-	"sp-std/std",
 	"strum/std",
 ]
 

substrate/primitives/consensus/beefy/src/commitment.rs

@@ -15,9 +15,10 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+use alloc::{vec, vec::Vec};
 use codec::{Decode, Encode, Error, Input};
+use core::cmp;
 use scale_info::TypeInfo;
-use sp_std::{cmp, prelude::*};
 
 use crate::{Payload, ValidatorSetId};
 
@@ -97,10 +98,10 @@ pub struct SignedCommitment<TBlockNumber, TSignature> {
 	pub signatures: Vec<Option<TSignature>>,
 }
 
-impl<TBlockNumber: sp_std::fmt::Debug, TSignature> sp_std::fmt::Display
+impl<TBlockNumber: core::fmt::Debug, TSignature> core::fmt::Display
 	for SignedCommitment<TBlockNumber, TSignature>
 {
-	fn fmt(&self, f: &mut sp_std::fmt::Formatter<'_>) -> sp_std::fmt::Result {
+	fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
 		let signatures_count = self.signatures.iter().filter(|s| s.is_some()).count();
 		write!(
 			f,
@@ -254,8 +255,8 @@ pub enum VersionedFinalityProof<N, S> {
 	V1(SignedCommitment<N, S>),
 }
 
-impl<N: sp_std::fmt::Debug, S> sp_std::fmt::Display for VersionedFinalityProof<N, S> {
+impl<N: core::fmt::Debug, S> core::fmt::Display for VersionedFinalityProof<N, S> {
-	fn fmt(&self, f: &mut sp_std::fmt::Formatter<'_>) -> sp_std::fmt::Result {
+	fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
 		match self {
 			VersionedFinalityProof::V1(sc) => write!(f, "VersionedFinalityProof::V1({})", sc),
 		}

substrate/primitives/consensus/beefy/src/lib.rs

@@ -31,6 +31,8 @@
 //! it will use a different set of keys. For Polkadot use case we plan to use `secp256k1` for BEEFY,
 //! while GRANDPA uses `ed25519`.
 
+extern crate alloc;
+
 mod commitment;
 mod payload;
 
@@ -44,13 +46,13 @@ pub mod test_utils;
 pub use commitment::{Commitment, SignedCommitment, VersionedFinalityProof};
 pub use payload::{known_payloads, BeefyPayloadId, Payload, PayloadProvider};
 
+use alloc::vec::Vec;
 use codec::{Codec, Decode, Encode};
 use core::fmt::{Debug, Display};
 use scale_info::TypeInfo;
 use sp_application_crypto::{AppCrypto, AppPublic, ByteArray, RuntimeAppPublic};
 use sp_core::H256;
 use sp_runtime::traits::{Hash, Keccak256, NumberFor};
-use sp_std::prelude::*;
 
 /// Key type for BEEFY module.
 pub const KEY_TYPE: sp_core::crypto::KeyTypeId = sp_application_crypto::key_types::BEEFY;

substrate/primitives/consensus/beefy/src/mmr.rs

@@ -26,7 +26,8 @@
 //! but we imagine they will be useful for other chains that either want to bridge with Polkadot
 //! or are completely standalone, but heavily inspired by Polkadot.
 
-use crate::{ecdsa_crypto::AuthorityId, ConsensusLog, MmrRootHash, Vec, BEEFY_ENGINE_ID};
+use crate::{ecdsa_crypto::AuthorityId, ConsensusLog, MmrRootHash, BEEFY_ENGINE_ID};
+use alloc::vec::Vec;
 use codec::{Decode, Encode, MaxEncodedLen};
 use scale_info::TypeInfo;
 use sp_runtime::{
@@ -150,10 +151,11 @@ pub use mmr_root_provider::MmrRootProvider;
 mod mmr_root_provider {
 	use super::*;
 	use crate::{known_payloads, payload::PayloadProvider, Payload};
+	use alloc::sync::Arc;
+	use core::marker::PhantomData;
 	use sp_api::ProvideRuntimeApi;
 	use sp_mmr_primitives::MmrApi;
 	use sp_runtime::traits::NumberFor;
-	use sp_std::{marker::PhantomData, sync::Arc};
 
 	/// A [`crate::Payload`] provider where payload is Merkle Mountain Range root hash.
 	///

substrate/primitives/consensus/beefy/src/payload.rs

@@ -15,10 +15,10 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+use alloc::{vec, vec::Vec};
 use codec::{Decode, Encode};
 use scale_info::TypeInfo;
 use sp_runtime::traits::Block;
-use sp_std::prelude::*;
 
 /// Id of different payloads in the [`crate::Commitment`] data.
 pub type BeefyPayloadId = [u8; 2];

substrate/primitives/consensus/beefy/src/witness.rs

@@ -23,9 +23,8 @@
 //! verification. This allows lowering the data and computation cost of verifying the
 //! signed commitment.
 
-use sp_std::prelude::*;
-
 use crate::commitment::{Commitment, SignedCommitment};
+use alloc::vec::Vec;
 
 /// A light form of [SignedCommitment].
 ///

substrate/primitives/consensus/grandpa/Cargo.toml

@@ -27,7 +27,6 @@ sp-application-crypto = { path = "../../application-crypto", default-features =
 sp-core = { path = "../../core", default-features = false }
 sp-keystore = { path = "../../keystore", default-features = false, optional = true }
 sp-runtime = { path = "../../runtime", default-features = false }
-sp-std = { path = "../../std", default-features = false }
 
 [features]
 default = ["std"]
@@ -42,7 +41,6 @@ std = [
 	"sp-core/std",
 	"sp-keystore/std",
 	"sp-runtime/std",
-	"sp-std/std",
 ]
 
 # Serde support without relying on std features.

substrate/primitives/consensus/grandpa/src/lib.rs

@@ -19,9 +19,12 @@
 
 #![cfg_attr(not(feature = "std"), no_std)]
 
+extern crate alloc;
+
 #[cfg(feature = "serde")]
 use serde::Serialize;
 
+use alloc::vec::Vec;
 use codec::{Codec, Decode, Encode};
 use scale_info::TypeInfo;
 #[cfg(feature = "std")]
@@ -30,7 +33,6 @@ use sp_runtime::{
 	traits::{Header as HeaderT, NumberFor},
 	ConsensusEngineId, RuntimeDebug,
 };
-use sp_std::vec::Vec;
 
 /// The log target to be used by client code.
 pub const CLIENT_LOG_TARGET: &str = "grandpa";

substrate/primitives/consensus/pow/Cargo.toml

@@ -20,7 +20,6 @@ codec = { package = "parity-scale-codec", version = "3.6.1", default-features =
 sp-api = { path = "../../api", default-features = false }
 sp-core = { path = "../../core", default-features = false }
 sp-runtime = { path = "../../runtime", default-features = false }
-sp-std = { path = "../../std", default-features = false }
 
 [features]
 default = ["std"]
@@ -29,5 +28,4 @@ std = [
 	"sp-api/std",
 	"sp-core/std",
 	"sp-runtime/std",
-	"sp-std/std",
 ]

substrate/primitives/consensus/pow/src/lib.rs

@@ -19,9 +19,12 @@
 
 #![cfg_attr(not(feature = "std"), no_std)]
 
+extern crate alloc;
+
+#[cfg(not(feature = "std"))]
+use alloc::vec::Vec;
 use codec::Decode;
 use sp_runtime::ConsensusEngineId;
-use sp_std::vec::Vec;
 
 /// The `ConsensusEngineId` of PoW.
 pub const POW_ENGINE_ID: ConsensusEngineId = [b'p', b'o', b'w', b'_'];

substrate/primitives/consensus/sassafras/Cargo.toml

@@ -26,7 +26,6 @@ sp-application-crypto = { path = "../../application-crypto", default-features =
 sp-consensus-slots = { path = "../slots", default-features = false }
 sp-core = { path = "../../core", default-features = false, features = ["bandersnatch-experimental"] }
 sp-runtime = { path = "../../runtime", default-features = false }
-sp-std = { path = "../../std", default-features = false }
 
 [features]
 default = ["std"]
@@ -39,7 +38,6 @@ std = [
 	"sp-consensus-slots/std",
 	"sp-core/std",
 	"sp-runtime/std",
-	"sp-std/std",
 ]
 
 # Serde support without relying on std features.

substrate/primitives/consensus/sassafras/src/digests.rs

@@ -25,8 +25,9 @@ use crate::{
 use scale_codec::{Decode, Encode, MaxEncodedLen};
 use scale_info::TypeInfo;
 
+#[cfg(not(feature = "std"))]
+use alloc::vec::Vec;
 use sp_runtime::{DigestItem, RuntimeDebug};
-use sp_std::vec::Vec;
 
 /// Epoch slot claim digest entry.
 ///

substrate/primitives/consensus/sassafras/src/lib.rs

@@ -21,11 +21,13 @@
 #![forbid(unsafe_code, missing_docs, unused_variables, unused_imports)]
 #![cfg_attr(not(feature = "std"), no_std)]
 
+extern crate alloc;
+
+use alloc::vec::Vec;
 use scale_codec::{Decode, Encode, MaxEncodedLen};
 use scale_info::TypeInfo;
 use sp_core::crypto::KeyTypeId;
 use sp_runtime::{ConsensusEngineId, RuntimeDebug};
-use sp_std::vec::Vec;
 
 pub use sp_consensus_slots::{Slot, SlotDuration};
 

substrate/primitives/consensus/sassafras/src/vrf.rs

@@ -18,9 +18,10 @@
 //! Utilities related to VRF input, pre-output and signatures.
 
 use crate::{Randomness, TicketBody, TicketId};
+#[cfg(not(feature = "std"))]
+use alloc::vec::Vec;
 use scale_codec::Encode;
 use sp_consensus_slots::Slot;
-use sp_std::vec::Vec;
 
 pub use sp_core::bandersnatch::{
 	ring_vrf::{RingProver, RingVerifier, RingVerifierData, RingVrfSignature},

substrate/primitives/consensus/slots/Cargo.toml

@@ -19,7 +19,6 @@ targets = ["x86_64-unknown-linux-gnu"]
 codec = { package = "parity-scale-codec", version = "3.6.1", default-features = false, features = ["derive", "max-encoded-len"] }
 scale-info = { version = "2.10.0", default-features = false, features = ["derive"] }
 serde = { features = ["alloc", "derive"], optional = true, workspace = true }
-sp-std = { path = "../../std", default-features = false }
 sp-timestamp = { path = "../../timestamp", default-features = false }
 
 [features]
@@ -28,7 +27,6 @@ std = [
 	"codec/std",
 	"scale-info/std",
 	"serde/std",
-	"sp-std/std",
 	"sp-timestamp/std",
 ]
 

substrate/primitives/crypto/ec-utils/Cargo.toml

@@ -28,7 +28,6 @@ ark-ed-on-bls12-377-ext = { version = "0.4.1", default-features = false, optiona
 ark-ed-on-bls12-377 = { version = "0.4.0", default-features = false, optional = true }
 ark-scale = { version = "0.0.12", default-features = false, features = ["hazmat"], optional = true }
 sp-runtime-interface = { path = "../../runtime-interface", default-features = false, optional = true }
-sp-std = { path = "../../std", default-features = false, optional = true }
 
 [features]
 default = ["std"]
@@ -47,9 +46,8 @@ std = [
 	"ark-ed-on-bls12-381-bandersnatch?/std",
 	"ark-scale?/std",
 	"sp-runtime-interface?/std",
-	"sp-std?/std",
 ]
-common = ["ark-ec", "ark-scale", "sp-runtime-interface", "sp-std"]
+common = ["ark-ec", "ark-scale", "sp-runtime-interface"]
 bls12-377 = ["ark-bls12-377", "ark-bls12-377-ext", "common"]
 bls12-381 = ["ark-bls12-381", "ark-bls12-381-ext", "common"]
 bw6-761 = ["ark-bw6-761", "ark-bw6-761-ext", "common"]

substrate/primitives/crypto/ec-utils/src/bls12_377.rs

@@ -18,10 +18,10 @@
 //! *BLS12-377* types and host functions.
 
 use crate::utils;
+use alloc::vec::Vec;
 use ark_bls12_377_ext::CurveHooks;
 use ark_ec::{pairing::Pairing, CurveConfig};
 use sp_runtime_interface::runtime_interface;
-use sp_std::vec::Vec;
 
 /// First pairing group definitions.
 pub mod g1 {

substrate/primitives/crypto/ec-utils/src/bls12_381.rs

@@ -18,10 +18,10 @@
 //! *BLS12-381* types and host functions.
 
 use crate::utils;
+use alloc::vec::Vec;
 use ark_bls12_381_ext::CurveHooks;
 use ark_ec::{pairing::Pairing, CurveConfig};
 use sp_runtime_interface::runtime_interface;
-use sp_std::vec::Vec;
 
 /// First pairing group definitions.
 pub mod g1 {

substrate/primitives/crypto/ec-utils/src/bw6_761.rs

@@ -18,10 +18,10 @@
 //! *BW6-761* types and host functions.
 
 use crate::utils;
+use alloc::vec::Vec;
 use ark_bw6_761_ext::CurveHooks;
 use ark_ec::{pairing::Pairing, CurveConfig};
 use sp_runtime_interface::runtime_interface;
-use sp_std::vec::Vec;
 
 /// First pairing group definitions.
 pub mod g1 {

substrate/primitives/crypto/ec-utils/src/ed_on_bls12_377.rs

@@ -18,10 +18,10 @@
 //! *Ed-on-BLS12-377* types and host functions.
 
 use crate::utils;
+use alloc::vec::Vec;
 use ark_ec::CurveConfig;
 use ark_ed_on_bls12_377_ext::CurveHooks;
 use sp_runtime_interface::runtime_interface;
-use sp_std::vec::Vec;
 
 /// Curve hooks jumping into [`host_calls`] host functions.
 #[derive(Copy, Clone)]

substrate/primitives/crypto/ec-utils/src/ed_on_bls12_381_bandersnatch.rs

@@ -19,10 +19,10 @@
 //! computationally expensive operations.
 
 use crate::utils;
+use alloc::vec::Vec;
 use ark_ec::CurveConfig;
 use ark_ed_on_bls12_381_bandersnatch_ext::CurveHooks;
 use sp_runtime_interface::runtime_interface;
-use sp_std::vec::Vec;
 
 /// Curve hooks jumping into [`host_calls`] host functions.
 #[derive(Copy, Clone)]

substrate/primitives/crypto/ec-utils/src/lib.rs

@@ -32,6 +32,8 @@
 #![warn(missing_docs)]
 #![cfg_attr(not(feature = "std"), no_std)]
 
+extern crate alloc;
+
 #[cfg(feature = "bls12-377")]
 pub mod bls12_377;
 #[cfg(feature = "bls12-381")]

substrate/primitives/crypto/ec-utils/src/utils.rs

@@ -21,6 +21,7 @@
 // curve may be excluded by the build we resort to `#[allow(unused)]` to
 // suppress the expected warning.
 
+use alloc::vec::Vec;
 use ark_ec::{
 	pairing::{MillerLoopOutput, Pairing},
 	short_weierstrass::{Affine as SWAffine, Projective as SWProjective, SWCurveConfig},
@@ -31,7 +32,6 @@ use ark_scale::{
 	ark_serialize::{CanonicalDeserialize, CanonicalSerialize, Compress, Validate},
 	scale::{Decode, Encode},
 };
-use sp_std::vec::Vec;
 
 // SCALE encoding parameters shared by all the enabled modules
 const SCALE_USAGE: u8 = ark_scale::make_usage(Compress::No, Validate::No);

substrate/primitives/externalities/Cargo.toml

@@ -19,9 +19,8 @@ targets = ["x86_64-unknown-linux-gnu"]
 [dependencies]
 codec = { package = "parity-scale-codec", version = "3.6.1", default-features = false }
 environmental = { version = "1.1.3", default-features = false }
-sp-std = { path = "../std", default-features = false }
 sp-storage = { path = "../storage", default-features = false }
 
 [features]
 default = ["std"]
-std = ["codec/std", "environmental/std", "sp-std/std", "sp-storage/std"]
+std = ["codec/std", "environmental/std", "sp-storage/std"]

substrate/primitives/externalities/src/extensions.rs

@@ -23,10 +23,12 @@
 //! It is required that each extension implements the [`Extension`] trait.
 
 use crate::Error;
-use sp_std::{
+use alloc::{
-	any::{Any, TypeId},
 	boxed::Box,
 	collections::btree_map::{BTreeMap, Entry},
+};
+use core::{
+	any::{Any, TypeId},
 	ops::DerefMut,
 };
 

substrate/primitives/externalities/src/lib.rs

@@ -25,11 +25,10 @@
 //!
 //! This crate exposes the main [`Externalities`] trait.
 
-use sp_std::{
+extern crate alloc;
-	any::{Any, TypeId},
+
-	boxed::Box,
+use alloc::{boxed::Box, vec::Vec};
-	vec::Vec,
+use core::any::{Any, TypeId};
-};
 
 use sp_storage::{ChildInfo, StateVersion, TrackedStorageKey};
 

substrate/primitives/genesis-builder/Cargo.toml

@@ -18,9 +18,8 @@ targets = ["x86_64-unknown-linux-gnu"]
 [dependencies]
 sp-api = { path = "../api", default-features = false }
 sp-runtime = { path = "../runtime", default-features = false }
-sp-std = { path = "../std", default-features = false }
 serde_json = { features = ["alloc", "arbitrary_precision"], workspace = true }
 
 [features]
 default = ["std"]
-std = ["serde_json/std", "sp-api/std", "sp-runtime/std", "sp-std/std"]
+std = ["serde_json/std", "sp-api/std", "sp-runtime/std"]

substrate/primitives/genesis-builder/src/lib.rs

@@ -31,6 +31,8 @@
 //! allows to catch and build the raw storage of `RuntimeGenesisConfig` which is the foundation for
 //! genesis block.
 
+extern crate alloc;
+
 /// The result type alias, used in build methods. `Err` contains formatted error message.
 pub type Result = core::result::Result<(), sp_runtime::RuntimeString>;
 
@@ -41,7 +43,7 @@ sp_api::decl_runtime_apis! {
 		///
 		/// This function instantiates the default `RuntimeGenesisConfig` struct for the runtime and serializes it into a JSON
 		/// blob. It returns a `Vec<u8>` containing the JSON representation of the default `RuntimeGenesisConfig`.
-		fn create_default_config() -> sp_std::vec::Vec<u8>;
+		fn create_default_config() -> alloc::vec::Vec<u8>;
 
 		/// Build `RuntimeGenesisConfig` from a JSON blob not using any defaults and store it in the storage.
 		///
@@ -50,6 +52,6 @@ sp_api::decl_runtime_apis! {
 		/// It is recommended to log any errors encountered during the process.
 		///
 		/// Please note that provided json blob must contain all `RuntimeGenesisConfig` fields, no defaults will be used.
-		fn build_config(json: sp_std::vec::Vec<u8>) -> Result;
+		fn build_config(json: alloc::vec::Vec<u8>) -> Result;
 	}
 }

substrate/primitives/inherents/Cargo.toml

@@ -23,7 +23,6 @@ scale-info = { version = "2.10.0", default-features = false, features = ["derive
 impl-trait-for-tuples = "0.2.2"
 thiserror = { optional = true, workspace = true }
 sp-runtime = { path = "../runtime", default-features = false, optional = true }
-sp-std = { path = "../std", default-features = false }
 
 [dev-dependencies]
 futures = "0.3.21"
@@ -35,6 +34,5 @@ std = [
 	"codec/std",
 	"scale-info/std",
 	"sp-runtime/std",
-	"sp-std/std",
 	"thiserror",
 ]

substrate/primitives/inherents/src/lib.rs

@@ -162,9 +162,11 @@
 #![cfg_attr(not(feature = "std"), no_std)]
 #![warn(missing_docs)]
 
+extern crate alloc;
+
 use codec::{Decode, Encode};
 
-use sp_std::{
+use alloc::{
 	collections::btree_map::{BTreeMap, Entry, IntoIter},
 	vec::Vec,
 };

substrate/primitives/merkle-mountain-range/Cargo.toml

@@ -24,7 +24,6 @@ sp-api = { path = "../api", default-features = false }
 sp-core = { path = "../core", default-features = false }
 sp-debug-derive = { path = "../debug-derive", default-features = false }
 sp-runtime = { path = "../runtime", default-features = false }
-sp-std = { path = "../std", default-features = false }
 thiserror = { optional = true, workspace = true }
 
 [dev-dependencies]
@@ -43,7 +42,6 @@ std = [
 	"sp-core/std",
 	"sp-debug-derive/std",
 	"sp-runtime/std",
-	"sp-std/std",
 ]
 
 # Serde support without relying on std features.

substrate/primitives/merkle-mountain-range/src/lib.rs

@@ -20,14 +20,16 @@
 #![cfg_attr(not(feature = "std"), no_std)]
 #![warn(missing_docs)]
 
+extern crate alloc;
+
 pub use mmr_lib;
 
+#[cfg(not(feature = "std"))]
+use alloc::vec::Vec;
+use core::fmt;
 use scale_info::TypeInfo;
 use sp_debug_derive::RuntimeDebug;
 use sp_runtime::traits;
-use sp_std::fmt;
-#[cfg(not(feature = "std"))]
-use sp_std::prelude::Vec;
 
 pub mod utils;
 
@@ -248,10 +250,10 @@ impl<H: traits::Hash, L: FullLeaf> DataOrHash<H, L> {
 pub struct Compact<H, T> {
 	/// Internal tuple representation.
 	pub tuple: T,
-	_hash: sp_std::marker::PhantomData<H>,
+	_hash: core::marker::PhantomData<H>,
 }
 
-impl<H, T> sp_std::ops::Deref for Compact<H, T> {
+impl<H, T> core::ops::Deref for Compact<H, T> {
 	type Target = T;
 
 	fn deref(&self) -> &Self::Target {

substrate/primitives/merkle-mountain-range/src/utils.rs

@@ -20,9 +20,9 @@
 use codec::Encode;
 use mmr_lib::helper;
 
-use sp_runtime::traits::{CheckedAdd, CheckedSub, Header, One};
 #[cfg(not(feature = "std"))]
-use sp_std::prelude::Vec;
+use alloc::vec::Vec;
+use sp_runtime::traits::{CheckedAdd, CheckedSub, Header, One};
 
 use crate::{Error, LeafIndex, NodeIndex};
 
@@ -131,7 +131,7 @@ impl NodesUtils {
 	/// Used for nodes added by now finalized blocks.
 	/// Never read keys using `node_canon_offchain_key` unless you sure that
 	/// there's no `node_offchain_key` key in the storage.
-	pub fn node_canon_offchain_key(prefix: &[u8], pos: NodeIndex) -> sp_std::prelude::Vec<u8> {
+	pub fn node_canon_offchain_key(prefix: &[u8], pos: NodeIndex) -> alloc::vec::Vec<u8> {
 		(prefix, pos).encode()
 	}
 }

substrate/primitives/metadata-ir/Cargo.toml

@@ -19,8 +19,7 @@ targets = ["x86_64-unknown-linux-gnu"]
 codec = { package = "parity-scale-codec", version = "3.6.1", default-features = false }
 frame-metadata = { version = "16.0.0", default-features = false, features = ["current"] }
 scale-info = { version = "2.10.0", default-features = false, features = ["derive"] }
-sp-std = { path = "../std", default-features = false }
 
 [features]
 default = ["std"]
-std = ["codec/std", "frame-metadata/std", "scale-info/std", "sp-std/std"]
+std = ["codec/std", "frame-metadata/std", "scale-info/std"]

substrate/primitives/metadata-ir/src/lib.rs

@@ -20,6 +20,8 @@
 #![cfg_attr(not(feature = "std"), no_std)]
 #![warn(missing_docs)]
 
+extern crate alloc;
+
 // Re-export.
 #[doc(hidden)]
 pub use frame_metadata;
@@ -52,8 +54,8 @@ pub fn into_version(metadata: MetadataIR, version: u32) -> Option<RuntimeMetadat
 }
 
 /// Returns the supported metadata versions.
-pub fn supported_versions() -> sp_std::vec::Vec<u32> {
+pub fn supported_versions() -> alloc::vec::Vec<u32> {
-	sp_std::vec![V14, V15]
+	alloc::vec![V14, V15]
 }
 
 /// Transform the IR to the latest stable metadata version.

substrate/primitives/mixnet/Cargo.toml

@@ -20,7 +20,6 @@ codec = { package = "parity-scale-codec", version = "3.6.1", default-features =
 scale-info = { version = "2.10.0", default-features = false, features = ["derive"] }
 sp-api = { default-features = false, path = "../api" }
 sp-application-crypto = { default-features = false, path = "../application-crypto" }
-sp-std = { default-features = false, path = "../std" }
 
 [features]
 default = ["std"]
@@ -29,5 +28,4 @@ std = [
 	"scale-info/std",
 	"sp-api/std",
 	"sp-application-crypto/std",
-	"sp-std/std",
 ]

substrate/primitives/mixnet/src/lib.rs

@@ -20,5 +20,7 @@
 #![warn(missing_docs)]
 #![cfg_attr(not(feature = "std"), no_std)]
 
+extern crate alloc;
+
 pub mod runtime_api;
 pub mod types;

substrate/primitives/mixnet/src/runtime_api.rs

@@ -18,7 +18,7 @@
 //! Runtime API for querying mixnet configuration and registering mixnodes.
 
 use super::types::{Mixnode, MixnodesErr, SessionIndex, SessionStatus};
-use sp_std::vec::Vec;
+use alloc::vec::Vec;
 
 sp_api::decl_runtime_apis! {
 	/// API to query the mixnet session status and mixnode sets, and to register mixnodes.

substrate/primitives/mixnet/src/types.rs

@@ -17,9 +17,9 @@
 
 //! Mixnet types used by both host and runtime.
 
+use alloc::vec::Vec;
 use codec::{Decode, Encode};
 use scale_info::TypeInfo;
-use sp_std::vec::Vec;
 
 mod app {
 	use sp_application_crypto::{app_crypto, key_types::MIXNET, sr25519};
@@ -90,8 +90,8 @@ pub enum MixnodesErr {
 	},
 }
 
-impl sp_std::fmt::Display for MixnodesErr {
+impl core::fmt::Display for MixnodesErr {
-	fn fmt(&self, fmt: &mut sp_std::fmt::Formatter) -> sp_std::fmt::Result {
+	fn fmt(&self, fmt: &mut core::fmt::Formatter) -> core::fmt::Result {
 		match self {
 			MixnodesErr::InsufficientRegistrations { num, min } =>
 				write!(fmt, "{num} mixnode(s) registered; {min} is the minimum"),

substrate/primitives/npos-elections/Cargo.toml

@@ -22,7 +22,6 @@ serde = { features = ["alloc", "derive"], optional = true, workspace = true }
 sp-arithmetic = { path = "../arithmetic", default-features = false }
 sp-core = { path = "../core", default-features = false }
 sp-runtime = { path = "../runtime", default-features = false }
-sp-std = { path = "../std", default-features = false }
 
 [dev-dependencies]
 rand = "0.8.5"
@@ -38,7 +37,6 @@ std = [
 	"sp-arithmetic/std",
 	"sp-core/std",
 	"sp-runtime/std",
-	"sp-std/std",
 ]
 
 # Serde support without relying on std features.

substrate/primitives/npos-elections/src/assignments.rs

@@ -18,6 +18,7 @@
 //! Structs and helpers for distributing a voter's stake among various winners.
 
 use crate::{ExtendedBalance, IdentifierT, PerThing128};
+use alloc::vec::Vec;
 #[cfg(feature = "serde")]
 use codec::{Decode, Encode};
 use sp_arithmetic::{
@@ -25,7 +26,6 @@ use sp_arithmetic::{
 	Normalizable, PerThing,
 };
 use sp_core::RuntimeDebug;
-use sp_std::vec::Vec;
 
 /// A voter's stake assignment among a set of targets, represented as ratios.
 #[derive(RuntimeDebug, Clone, Default)]

substrate/primitives/npos-elections/src/balancing.rs

@@ -27,8 +27,8 @@
 //! See [`balance`] for more information.
 
 use crate::{BalancingConfig, Edge, ExtendedBalance, IdentifierT, Voter};
+use alloc::vec::Vec;
 use sp_arithmetic::traits::Zero;
-use sp_std::prelude::*;
 
 /// Balance the weight distribution of a given `voters` at most `iterations` times, or up until the
 /// point where the biggest difference created per iteration of all stakes is `tolerance`. If this

substrate/primitives/npos-elections/src/helpers.rs

@@ -18,8 +18,8 @@
 //! Helper methods for npos-elections.
 
 use crate::{Assignment, Error, IdentifierT, PerThing128, StakedAssignment, VoteWeight};
+use alloc::vec::Vec;
 use sp_arithmetic::PerThing;
-use sp_std::prelude::*;
 
 /// Converts a vector of ratio assignments into ones with absolute budget value.
 ///

substrate/primitives/npos-elections/src/lib.rs

@@ -74,15 +74,16 @@
 
 #![cfg_attr(not(feature = "std"), no_std)]
 
+extern crate alloc;
+
+use alloc::{collections::btree_map::BTreeMap, rc::Rc, vec, vec::Vec};
 use codec::{Decode, Encode, MaxEncodedLen};
+use core::{cell::RefCell, cmp::Ordering};
 use scale_info::TypeInfo;
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
 use sp_arithmetic::{traits::Zero, Normalizable, PerThing, Rational128, ThresholdOrd};
 use sp_core::{bounded::BoundedVec, RuntimeDebug};
-use sp_std::{
-	cell::RefCell, cmp::Ordering, collections::btree_map::BTreeMap, prelude::*, rc::Rc, vec,
-};
 
 #[cfg(test)]
 mod mock;
@@ -198,7 +199,7 @@ impl ElectionScore {
 	}
 }
 
-impl sp_std::cmp::Ord for ElectionScore {
+impl core::cmp::Ord for ElectionScore {
 	fn cmp(&self, other: &Self) -> Ordering {
 		// we delegate this to the lexicographic cmp of slices`, and to incorporate that we want the
 		// third element to be minimized, we swap them.
@@ -210,7 +211,7 @@ impl sp_std::cmp::Ord for ElectionScore {
 	}
 }
 
-impl sp_std::cmp::PartialOrd for ElectionScore {
+impl core::cmp::PartialOrd for ElectionScore {
 	fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
 		Some(self.cmp(other))
 	}
@@ -278,8 +279,8 @@ impl<AccountId: Clone> Edge<AccountId> {
 }
 
 #[cfg(feature = "std")]
-impl<A: IdentifierT> sp_std::fmt::Debug for Edge<A> {
+impl<A: IdentifierT> core::fmt::Debug for Edge<A> {
-	fn fmt(&self, f: &mut sp_std::fmt::Formatter<'_>) -> sp_std::fmt::Result {
+	fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
 		write!(f, "Edge({:?}, weight = {:?})", self.who, self.weight)
 	}
 }
@@ -299,7 +300,7 @@ pub struct Voter<AccountId> {
 
 #[cfg(feature = "std")]
 impl<A: IdentifierT> std::fmt::Debug for Voter<A> {
-	fn fmt(&self, f: &mut sp_std::fmt::Formatter<'_>) -> sp_std::fmt::Result {
+	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 		write!(f, "Voter({:?}, budget = {}, edges = {:?})", self.who, self.budget, self.edges)
 	}
 }

substrate/primitives/npos-elections/src/mock.rs

@@ -19,12 +19,12 @@
 
 #![cfg(test)]
 
+use alloc::collections::btree_map::BTreeMap;
 use sp_arithmetic::{
 	traits::{One, SaturatedConversion, Zero},
 	PerThing,
 };
 use sp_runtime::assert_eq_error_rate;
-use sp_std::collections::btree_map::BTreeMap;
 
 use crate::{seq_phragmen, Assignment, ElectionResult, ExtendedBalance, PerThing128, VoteWeight};
 
@@ -131,7 +131,7 @@ where
 		if let Some(winner) = candidates
 			.iter_mut()
 			.filter(|c| !c.elected)
-			.min_by(|x, y| x.score.partial_cmp(&y.score).unwrap_or(sp_std::cmp::Ordering::Equal))
+			.min_by(|x, y| x.score.partial_cmp(&y.score).unwrap_or(core::cmp::Ordering::Equal))
 		{
 			winner.elected = true;
 			for n in &mut voters {
@@ -226,10 +226,10 @@ where
 	if backing_backed_stake.len() > 0 {
 		let max_stake = backing_backed_stake
 			.iter()
-			.max_by(|x, y| x.partial_cmp(&y).unwrap_or(sp_std::cmp::Ordering::Equal))
+			.max_by(|x, y| x.partial_cmp(&y).unwrap_or(core::cmp::Ordering::Equal))
 			.expect("vector with positive length will have a max; qed");
 		let min_stake = backed_stakes_iter
-			.min_by(|x, y| x.partial_cmp(&y).unwrap_or(sp_std::cmp::Ordering::Equal))
+			.min_by(|x, y| x.partial_cmp(&y).unwrap_or(core::cmp::Ordering::Equal))
 			.expect("iterator with positive length will have a min; qed");
 
 		difference = max_stake - min_stake;
@@ -254,7 +254,7 @@ where
 		support_map
 			.get(&x.0)
 			.and_then(|x| support_map.get(&y.0).and_then(|y| x.total.partial_cmp(&y.total)))
-			.unwrap_or(sp_std::cmp::Ordering::Equal)
+			.unwrap_or(core::cmp::Ordering::Equal)
 	});
 
 	let mut cumulative_stake = 0.0;

substrate/primitives/npos-elections/src/node.rs

@@ -17,7 +17,8 @@
 
 //! (very) Basic implementation of a graph node used in the reduce algorithm.
 
-use sp_std::{cell::RefCell, fmt, prelude::*, rc::Rc};
+use alloc::{rc::Rc, vec::Vec};
+use core::{cell::RefCell, fmt};
 
 /// The role that a node can accept.
 #[derive(PartialEq, Eq, Ord, PartialOrd, Clone, Debug)]
@@ -49,8 +50,8 @@ impl<A> NodeId<A> {
 }
 
 #[cfg(feature = "std")]
-impl<A: fmt::Debug> sp_std::fmt::Debug for NodeId<A> {
+impl<A: fmt::Debug> fmt::Debug for NodeId<A> {
-	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> sp_std::fmt::Result {
+	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 		write!(
 			f,
 			"Node({:?}, {:?})",

substrate/primitives/npos-elections/src/phragmen.rs

@@ -24,12 +24,12 @@ use crate::{
 	balancing, setup_inputs, BalancingConfig, CandidatePtr, ElectionResult, ExtendedBalance,
 	IdentifierT, PerThing128, VoteWeight, Voter,
 };
+use alloc::vec::Vec;
 use sp_arithmetic::{
 	helpers_128bit::multiply_by_rational_with_rounding,
 	traits::{Bounded, Zero},
 	Rational128, Rounding,
 };
-use sp_std::prelude::*;
 
 /// The denominator used for loads. Since votes are collected as u64, the smallest ratio that we
 /// might collect is `1/approval_stake` where approval stake is the sum of votes. Hence, some number

substrate/primitives/npos-elections/src/phragmms.rs

@@ -25,8 +25,8 @@ use crate::{
 	balance, setup_inputs, BalancingConfig, CandidatePtr, ElectionResult, ExtendedBalance,
 	IdentifierT, PerThing128, VoteWeight, Voter,
 };
+use alloc::{rc::Rc, vec, vec::Vec};
 use sp_arithmetic::{traits::Bounded, PerThing, Rational128};
-use sp_std::{prelude::*, rc::Rc};
 
 /// Execute the phragmms method.
 ///
@@ -232,8 +232,8 @@ pub(crate) fn apply_elected<AccountId: IdentifierT>(
 mod tests {
 	use super::*;
 	use crate::{Assignment, ElectionResult};
+	use alloc::rc::Rc;
 	use sp_runtime::{Perbill, Percent};
-	use sp_std::rc::Rc;
 
 	#[test]
 	fn basic_election_manual_works() {

substrate/primitives/npos-elections/src/pjr.rs

@@ -26,8 +26,8 @@ use crate::{
 	Candidate, CandidatePtr, Edge, ExtendedBalance, IdentifierT, Support, SupportMap, Supports,
 	VoteWeight, Voter,
 };
+use alloc::{collections::btree_map::BTreeMap, rc::Rc, vec::Vec};
 use sp_arithmetic::{traits::Zero, Perbill};
-use sp_std::{collections::btree_map::BTreeMap, rc::Rc, vec::Vec};
 /// The type used as the threshold.
 ///
 /// Just some reading sugar; Must always be same as [`ExtendedBalance`];

substrate/primitives/npos-elections/src/reduce.rs

@@ -51,11 +51,12 @@ use crate::{
 	node::{Node, NodeId, NodeRef, NodeRole},
 	ExtendedBalance, IdentifierT, StakedAssignment,
 };
-use sp_arithmetic::traits::{Bounded, Zero};
+use alloc::{
-use sp_std::{
 	collections::btree_map::{BTreeMap, Entry::*},
-	prelude::*,
+	vec,
+	vec::Vec,
 };
+use sp_arithmetic::traits::{Bounded, Zero};
 
 /// Map type used for reduce_4. Can be easily swapped with HashMap.
 type Map<A> = BTreeMap<(A, A), A>;

substrate/primitives/npos-elections/src/traits.rs

@@ -18,8 +18,8 @@
 //! Traits for the npos-election operations.
 
 use crate::ExtendedBalance;
+use core::{fmt::Debug, ops::Mul};
 use sp_arithmetic::PerThing;
-use sp_std::{fmt::Debug, ops::Mul, prelude::*};
 
 /// an aggregator trait for a generic type of a voter/target identifier. This usually maps to
 /// substrate's account id.

substrate/primitives/session/Cargo.toml

@@ -22,7 +22,6 @@ sp-api = { path = "../api", default-features = false }
 sp-core = { path = "../core", default-features = false }
 sp-runtime = { path = "../runtime", optional = true }
 sp-staking = { path = "../staking", default-features = false }
-sp-std = { path = "../std", default-features = false }
 sp-keystore = { path = "../keystore", optional = true }
 
 [features]
@@ -35,5 +34,4 @@ std = [
 	"sp-keystore/std",
 	"sp-runtime/std",
 	"sp-staking/std",
-	"sp-std/std",
 ]

substrate/primitives/session/src/lib.rs

@@ -19,6 +19,8 @@
 
 #![cfg_attr(not(feature = "std"), no_std)]
 
+extern crate alloc;
+
 use codec::{Decode, Encode};
 
 #[cfg(feature = "std")]
@@ -26,9 +28,9 @@ use sp_api::ProvideRuntimeApi;
 #[cfg(feature = "std")]
 use sp_runtime::traits::Block as BlockT;
 
+use alloc::vec::Vec;
 use sp_core::RuntimeDebug;
 use sp_staking::SessionIndex;
-use sp_std::vec::Vec;
 
 pub mod runtime_api;
 pub use runtime_api::*;

substrate/primitives/session/src/runtime_api.rs

@@ -15,8 +15,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+use alloc::vec::Vec;
 pub use sp_core::crypto::KeyTypeId;
-use sp_std::prelude::*;
 
 sp_api::decl_runtime_apis! {
 	/// Session keys runtime api.

substrate/primitives/staking/Cargo.toml

@@ -23,7 +23,6 @@ impl-trait-for-tuples = "0.2.2"
 
 sp-core = { path = "../core", default-features = false }
 sp-runtime = { path = "../runtime", default-features = false }
-sp-std = { path = "../std", default-features = false }
 
 [features]
 default = ["std"]
@@ -33,6 +32,5 @@ std = [
 	"serde/std",
 	"sp-core/std",
 	"sp-runtime/std",
-	"sp-std/std",
 ]
 runtime-benchmarks = ["sp-runtime/runtime-benchmarks"]

substrate/primitives/staking/src/lib.rs

@@ -20,14 +20,17 @@
 //! A crate which contains primitives that are useful for implementation that uses staking
 //! approaches in general. Definitions related to sessions, slashing, etc go here.
 
+extern crate alloc;
+
 use crate::currency_to_vote::CurrencyToVote;
+use alloc::{collections::btree_map::BTreeMap, vec, vec::Vec};
 use codec::{Decode, Encode, FullCodec, HasCompact, MaxEncodedLen};
+use core::ops::Sub;
 use scale_info::TypeInfo;
 use sp_runtime::{
 	traits::{AtLeast32BitUnsigned, Zero},
 	DispatchError, DispatchResult, RuntimeDebug, Saturating,
 };
-use sp_std::{collections::btree_map::BTreeMap, ops::Sub, vec, vec::Vec};
 
 pub mod offence;
 
@@ -172,7 +175,7 @@ pub trait StakingInterface {
 		+ Saturating;
 
 	/// AccountId type used by the staking system.
-	type AccountId: Clone + sp_std::fmt::Debug;
+	type AccountId: Clone + core::fmt::Debug;
 
 	/// Means of converting Currency to VoteWeight.
 	type CurrencyToVote: CurrencyToVote<Self::Balance>;

substrate/primitives/staking/src/offence.rs

@@ -18,10 +18,10 @@
 //! Common traits and types that are useful for describing offences for usage in environments
 //! that use staking.
 
+use alloc::vec::Vec;
 use codec::{Decode, Encode};
 use sp_core::Get;
 use sp_runtime::{transaction_validity::TransactionValidityError, DispatchError, Perbill};
-use sp_std::vec::Vec;
 
 use crate::SessionIndex;
 

substrate/primitives/state-machine/Cargo.toml

@@ -28,7 +28,6 @@ tracing = { version = "0.1.29", optional = true }
 sp-core = { path = "../core", default-features = false }
 sp-externalities = { path = "../externalities", default-features = false }
 sp-panic-handler = { path = "../panic-handler", optional = true }
-sp-std = { path = "../std", default-features = false }
 sp-trie = { path = "../trie", default-features = false }
 trie-db = { version = "0.28.0", default-features = false }
 
@@ -51,7 +50,6 @@ std = [
 	"sp-externalities/std",
 	"sp-panic-handler",
 	"sp-runtime/std",
-	"sp-std/std",
 	"sp-trie/std",
 	"thiserror",
 	"tracing",

substrate/primitives/state-machine/src/backend.rs

@@ -23,13 +23,13 @@ use crate::{
 	trie_backend_essence::TrieBackendStorage, ChildStorageCollection, StorageCollection,
 	StorageKey, StorageValue, UsageInfo,
 };
+use alloc::vec::Vec;
 use codec::Encode;
 use core::marker::PhantomData;
 use hash_db::Hasher;
 use sp_core::storage::{ChildInfo, StateVersion, TrackedStorageKey};
 #[cfg(feature = "std")]
 use sp_core::traits::RuntimeCode;
-use sp_std::vec::Vec;
 use sp_trie::{MerkleValue, PrefixedMemoryDB};
 
 /// A struct containing arguments for iterating over the storage.
@@ -179,7 +179,7 @@ pub type BackendTransaction<H> = PrefixedMemoryDB<H>;
 /// to it.
 ///
 /// The clone operation (if implemented) should be cheap.
-pub trait Backend<H: Hasher>: sp_std::fmt::Debug {
+pub trait Backend<H: Hasher>: core::fmt::Debug {
 	/// An error type when fetching data is not possible.
 	type Error: super::Error;
 

substrate/primitives/state-machine/src/ext.rs

@@ -32,12 +32,10 @@ use sp_core::storage::{
 use sp_externalities::{Extension, ExtensionStore, Externalities, MultiRemovalResults};
 
 use crate::{log_error, trace, warn};
-use sp_std::{
+use alloc::{boxed::Box, vec, vec::Vec};
+use core::{
 	any::{Any, TypeId},
-	boxed::Box,
 	cmp::Ordering,
-	vec,
-	vec::Vec,
 };
 #[cfg(feature = "std")]
 use std::error;
@@ -739,7 +737,7 @@ impl<'a> StorageAppend<'a> {
 	pub fn append(&mut self, value: Vec<u8>) {
 		let value = vec![EncodeOpaqueValue(value)];
 
-		let item = sp_std::mem::take(self.0);
+		let item = core::mem::take(self.0);
 
 		*self.0 = match Vec::<EncodeOpaqueValue>::append_or_new(item, &value) {
 			Ok(item) => item,

substrate/primitives/state-machine/src/lib.rs

@@ -20,6 +20,8 @@
 #![warn(missing_docs)]
 #![cfg_attr(not(feature = "std"), no_std)]
 
+extern crate alloc;
+
 pub mod backend;
 #[cfg(feature = "std")]
 mod basic;
@@ -118,8 +120,8 @@ pub type DefaultError = String;
 pub struct DefaultError;
 
 #[cfg(not(feature = "std"))]
-impl sp_std::fmt::Display for DefaultError {
+impl core::fmt::Display for DefaultError {
-	fn fmt(&self, f: &mut sp_std::fmt::Formatter) -> sp_std::fmt::Result {
+	fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
 		write!(f, "DefaultError")
 	}
 }

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.

substrate/primitives/state-machine/src/trie_backend.rs

@@ -297,7 +297,7 @@ struct CachedIter<S, H, C, R>
 where
 	H: Hasher,
 {
-	last_key: sp_std::vec::Vec<u8>,
+	last_key: alloc::vec::Vec<u8>,
 	iter: RawIter<S, H, C, R>,
 }
 
@@ -390,9 +390,9 @@ where
 }
 
 impl<S: TrieBackendStorage<H>, H: Hasher, C: TrieCacheProvider<H>, R: TrieRecorderProvider<H>>
-	sp_std::fmt::Debug for TrieBackend<S, H, C, R>
+	core::fmt::Debug for TrieBackend<S, H, C, R>
 {
-	fn fmt(&self, f: &mut sp_std::fmt::Formatter<'_>) -> sp_std::fmt::Result {
+	fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
 		write!(f, "TrieBackend")
 	}
 }

substrate/primitives/state-machine/src/trie_backend_essence.rs

@@ -23,14 +23,15 @@ use crate::{
 	trie_backend::TrieCacheProvider,
 	warn, StorageKey, StorageValue,
 };
+#[cfg(feature = "std")]
+use alloc::sync::Arc;
+use alloc::{boxed::Box, vec::Vec};
 use codec::Codec;
+use core::marker::PhantomData;
 use hash_db::{self, AsHashDB, HashDB, HashDBRef, Hasher, Prefix};
 #[cfg(feature = "std")]
 use parking_lot::RwLock;
 use sp_core::storage::{ChildInfo, ChildType, StateVersion};
-#[cfg(feature = "std")]
-use sp_std::sync::Arc;
-use sp_std::{boxed::Box, marker::PhantomData, vec::Vec};
 use sp_trie::{
 	child_delta_trie_root, delta_trie_root, empty_child_trie_root,
 	read_child_trie_first_descedant_value, read_child_trie_hash, read_child_trie_value,
@@ -55,7 +56,7 @@ macro_rules! format {
 	};
 }
 
-type Result<V> = sp_std::result::Result<V, crate::DefaultError>;
+type Result<V> = core::result::Result<V, crate::DefaultError>;
 
 /// Patricia trie-based storage trait.
 pub trait Storage<H: Hasher>: Send + Sync {

substrate/primitives/statement-store/Cargo.toml

@@ -21,7 +21,6 @@ scale-info = { version = "2.10.0", default-features = false, features = ["derive
 sp-core = { path = "../core", default-features = false }
 sp-crypto-hashing = { path = "../crypto/hashing", default-features = false }
 sp-runtime = { path = "../runtime", default-features = false }
-sp-std = { path = "../std", default-features = false }
 sp-api = { path = "../api", default-features = false }
 sp-application-crypto = { path = "../application-crypto", default-features = false }
 sp-runtime-interface = { path = "../runtime-interface", default-features = false }
@@ -57,7 +56,6 @@ std = [
 	"sp-externalities/std",
 	"sp-runtime-interface/std",
 	"sp-runtime/std",
-	"sp-std/std",
 	"thiserror",
 	"x25519-dalek",
 ]

substrate/primitives/statement-store/src/lib.rs

@@ -20,13 +20,15 @@
 
 //! A crate which contains statement-store primitives.
 
+extern crate alloc;
+
+use alloc::vec::Vec;
 use codec::{Decode, Encode};
 use scale_info::TypeInfo;
 use sp_application_crypto::RuntimeAppPublic;
 #[cfg(feature = "std")]
 use sp_core::Pair;
 use sp_runtime_interface::pass_by::PassByCodec;
-use sp_std::vec::Vec;
 
 /// Statement topic.
 pub type Topic = [u8; 32];

substrate/primitives/statement-store/src/runtime_api.rs

@@ -18,11 +18,11 @@
 //! Runtime support for the statement store.
 
 use crate::{Hash, Statement, Topic};
+use alloc::vec::Vec;
 use codec::{Decode, Encode};
 use scale_info::TypeInfo;
 use sp_runtime::RuntimeDebug;
 use sp_runtime_interface::{pass_by::PassByEnum, runtime_interface};
-use sp_std::vec::Vec;
 
 #[cfg(feature = "std")]
 use sp_externalities::ExternalitiesExt;

substrate/primitives/storage/Cargo.toml

@@ -22,7 +22,6 @@ impl-serde = { version = "0.4.0", optional = true, default-features = false }
 ref-cast = "1.0.0"
 serde = { features = ["alloc", "derive"], optional = true, workspace = true }
 sp-debug-derive = { path = "../debug-derive", default-features = false }
-sp-std = { path = "../std", default-features = false }
 
 [features]
 default = ["std"]
@@ -31,7 +30,6 @@ std = [
 	"impl-serde/std",
 	"serde/std",
 	"sp-debug-derive/std",
-	"sp-std/std",
 ]
 
 # Serde support without relying on std features.

substrate/primitives/storage/src/lib.rs

@@ -19,18 +19,19 @@
 
 #![cfg_attr(not(feature = "std"), no_std)]
 
-use core::fmt::Display;
+extern crate alloc;
 
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
 use sp_debug_derive::RuntimeDebug;
 
+use alloc::vec::Vec;
 use codec::{Decode, Encode};
-use ref_cast::RefCast;
+use core::{
-use sp_std::{
+	fmt::Display,
 	ops::{Deref, DerefMut},
-	vec::Vec,
 };
+use ref_cast::RefCast;
 
 /// Storage key.
 #[derive(PartialEq, Eq, RuntimeDebug)]
@@ -49,9 +50,7 @@ impl AsRef<[u8]> for StorageKey {
 }
 
 /// Storage key with read/write tracking information.
-#[derive(
+#[derive(PartialEq, Eq, Ord, PartialOrd, core::hash::Hash, RuntimeDebug, Clone, Encode, Decode)]
-	PartialEq, Eq, Ord, PartialOrd, sp_std::hash::Hash, RuntimeDebug, Clone, Encode, Decode,
-)]
 pub struct TrackedStorageKey {
 	pub key: Vec<u8>,
 	pub reads: u32,
@@ -441,7 +440,7 @@ impl From<StateVersion> for u8 {
 
 impl TryFrom<u8> for StateVersion {
 	type Error = ();
-	fn try_from(val: u8) -> sp_std::result::Result<StateVersion, ()> {
+	fn try_from(val: u8) -> core::result::Result<StateVersion, ()> {
 		match val {
 			0 => Ok(StateVersion::V0),
 			1 => Ok(StateVersion::V1),

substrate/primitives/test-primitives/Cargo.toml

@@ -21,7 +21,6 @@ serde = { features = ["derive"], optional = true, workspace = true }
 sp-application-crypto = { path = "../application-crypto", default-features = false }
 sp-core = { path = "../core", default-features = false }
 sp-runtime = { path = "../runtime", default-features = false }
-sp-std = { path = "../std", default-features = false }
 
 [features]
 default = ["std"]
@@ -32,7 +31,6 @@ std = [
 	"sp-application-crypto/std",
 	"sp-core/std",
 	"sp-runtime/std",
-	"sp-std/std",
 ]
 
 # Serde support without relying on std features.

substrate/primitives/test-primitives/src/lib.rs

@@ -19,14 +19,16 @@
 
 #![cfg_attr(not(feature = "std"), no_std)]
 
+extern crate alloc;
+
 use codec::{Decode, Encode};
 
 pub use sp_application_crypto;
 use sp_application_crypto::sr25519;
 
+use alloc::vec::Vec;
 pub use sp_core::{hash::H256, RuntimeDebug};
 use sp_runtime::traits::{BlakeTwo256, Extrinsic as ExtrinsicT, Verify};
-use sp_std::vec::Vec;
 
 /// Extrinsic for test-runtime.
 #[derive(Clone, PartialEq, Eq, Encode, Decode, RuntimeDebug, scale_info::TypeInfo)]

substrate/primitives/timestamp/Cargo.toml

@@ -21,7 +21,6 @@ codec = { package = "parity-scale-codec", version = "3.6.1", default-features =
 thiserror = { optional = true, workspace = true }
 sp-inherents = { path = "../inherents", default-features = false }
 sp-runtime = { path = "../runtime", default-features = false }
-sp-std = { path = "../std", default-features = false }
 
 [features]
 default = ["std"]
@@ -30,6 +29,5 @@ std = [
 	"codec/std",
 	"sp-inherents/std",
 	"sp-runtime/std",
-	"sp-std/std",
 	"thiserror",
 ]

substrate/primitives/tracing/Cargo.toml

@@ -21,7 +21,6 @@ features = ["with-tracing"]
 targets = ["wasm32-unknown-unknown", "x86_64-unknown-linux-gnu"]
 
 [dependencies]
-sp-std = { path = "../std", default-features = false }
 codec = { version = "3.6.1", package = "parity-scale-codec", default-features = false, features = [
 	"derive",
 ] }
@@ -36,7 +35,6 @@ default = ["std"]
 with-tracing = ["codec/derive", "codec/full"]
 std = [
 	"codec/std",
-	"sp-std/std",
 	"tracing-core/std",
 	"tracing-subscriber",
 	"tracing/std",

substrate/primitives/tracing/src/lib.rs

@@ -37,6 +37,8 @@
 
 #![cfg_attr(not(feature = "std"), no_std)]
 
+extern crate alloc;
+
 #[cfg(feature = "std")]
 use tracing;
 pub use tracing::{

substrate/primitives/tracing/src/types.rs

@@ -15,11 +15,11 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+use alloc::{vec, vec::Vec};
 use codec::{Decode, Encode};
 /// Types for wasm based tracing. Loosly inspired by `tracing-core` but
 /// optimised for the specific use case.
 use core::{fmt::Debug, format_args};
-use sp_std::{vec, vec::Vec, Writer};
 
 /// The Tracing Level – the user can filter by this
 #[derive(Clone, Encode, Decode, Debug)]
@@ -132,9 +132,9 @@ impl From<bool> for WasmValue {
 
 impl From<core::fmt::Arguments<'_>> for WasmValue {
 	fn from(inp: core::fmt::Arguments<'_>) -> WasmValue {
-		let mut buf = Writer::default();
+		let mut buf = alloc::string::String::default();
 		core::fmt::write(&mut buf, inp).expect("Writing of arguments doesn't fail");
-		WasmValue::Formatted(buf.into_inner())
+		WasmValue::Formatted(buf.into_bytes())
 	}
 }
 

substrate/primitives/transaction-pool/src/lib.rs

@@ -20,4 +20,6 @@
 #![warn(missing_docs)]
 #![cfg_attr(not(feature = "std"), no_std)]
 
+extern crate alloc;
+
 pub mod runtime_api;

substrate/primitives/transaction-storage-proof/Cargo.toml

@@ -22,7 +22,6 @@ scale-info = { version = "2.10.0", default-features = false, features = ["derive
 sp-core = { path = "../core", optional = true }
 sp-inherents = { path = "../inherents", default-features = false }
 sp-runtime = { path = "../runtime", default-features = false }
-sp-std = { path = "../std", default-features = false }
 sp-trie = { path = "../trie", optional = true }
 
 [features]
@@ -34,6 +33,5 @@ std = [
 	"sp-core/std",
 	"sp-inherents/std",
 	"sp-runtime/std",
-	"sp-std/std",
 	"sp-trie/std",
 ]

substrate/primitives/transaction-storage-proof/src/lib.rs

@@ -20,8 +20,11 @@
 
 #![cfg_attr(not(feature = "std"), no_std)]
 
-use sp_std::{prelude::*, result::Result};
+extern crate alloc;
 
+use core::result::Result;
+
+use alloc::vec::Vec;
 use codec::{Decode, Encode};
 use sp_inherents::{InherentData, InherentIdentifier, IsFatalError};
 use sp_runtime::traits::{Block as BlockT, NumberFor};

substrate/primitives/trie/Cargo.toml

@@ -35,7 +35,6 @@ tracing = { version = "0.1.29", optional = true }
 trie-db = { version = "0.28.0", default-features = false }
 trie-root = { version = "0.18.0", default-features = false }
 sp-core = { path = "../core", default-features = false }
-sp-std = { path = "../std", default-features = false }
 sp-externalities = { path = "../externalities", default-features = false }
 schnellru = { version = "0.2.1", optional = true }
 
@@ -62,7 +61,6 @@ std = [
 	"sp-core/std",
 	"sp-externalities/std",
 	"sp-runtime/std",
-	"sp-std/std",
 	"thiserror",
 	"tracing",
 	"trie-db/std",

substrate/primitives/trie/src/error.rs

@@ -15,7 +15,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use sp_std::{boxed::Box, vec::Vec};
+use alloc::{boxed::Box, vec::Vec};
 
 /// Error type used for trie related errors.
 #[derive(Debug, PartialEq, Eq, Clone)]

substrate/primitives/trie/src/lib.rs

@@ -19,6 +19,8 @@
 
 #![cfg_attr(not(feature = "std"), no_std)]
 
+extern crate alloc;
+
 #[cfg(feature = "std")]
 pub mod cache;
 mod error;
@@ -33,6 +35,8 @@ mod trie_stream;
 #[cfg(feature = "std")]
 pub mod proof_size_extension;
 
+use alloc::{borrow::Borrow, boxed::Box, vec, vec::Vec};
+use core::marker::PhantomData;
 /// Our `NodeCodec`-specific error.
 pub use error::Error;
 /// Various re-exports from the `hash-db` crate.
@@ -42,7 +46,6 @@ use hash_db::{Hasher, Prefix};
 pub use memory_db::{prefixed_key, HashKey, KeyFunction, PrefixedKey};
 /// The Substrate format implementation of `NodeCodec`.
 pub use node_codec::NodeCodec;
-use sp_std::{borrow::Borrow, boxed::Box, marker::PhantomData, vec::Vec};
 pub use storage_proof::{CompactProof, StorageProof};
 /// Trie codec reexport, mainly child trie support
 /// for trie compact proof.
@@ -500,7 +503,7 @@ pub struct KeySpacedDBMut<'a, DB: ?Sized, H>(&'a mut DB, &'a [u8], PhantomData<H
 /// Utility function used to merge some byte data (keyspace) and `prefix` data
 /// before calling key value database primitives.
 fn keyspace_as_prefix_alloc(ks: &[u8], prefix: Prefix) -> (Vec<u8>, Option<u8>) {
-	let mut result = sp_std::vec![0; ks.len() + prefix.0.len()];
+	let mut result = vec![0; ks.len() + prefix.0.len()];
 	result[..ks.len()].copy_from_slice(ks);
 	result[ks.len()..].copy_from_slice(prefix.0);
 	(result, prefix.1)

substrate/primitives/trie/src/node_codec.rs

@@ -19,9 +19,10 @@
 
 use super::node_header::{NodeHeader, NodeKind};
 use crate::{error::Error, trie_constants};
+use alloc::{borrow::Borrow, vec::Vec};
 use codec::{Compact, Decode, Encode, Input};
+use core::{marker::PhantomData, ops::Range};
 use hash_db::Hasher;
-use sp_std::{borrow::Borrow, marker::PhantomData, ops::Range, vec::Vec};
 use trie_db::{
 	nibble_ops,
 	node::{NibbleSlicePlan, NodeHandlePlan, NodePlan, Value, ValuePlan},
@@ -30,7 +31,7 @@ use trie_db::{
 
 /// Helper struct for trie node decoder. This implements `codec::Input` on a byte slice, while
 /// tracking the absolute position. This is similar to `std::io::Cursor` but does not implement
-/// `Read` and `io` is not in `sp-std`.
+/// `Read` and `io` are not in `core` or `alloc`.
 struct ByteSliceInput<'a> {
 	data: &'a [u8],
 	offset: usize,