From db18dcac34fc3c3ddc20c3b42331f8d5fa7014b5 Mon Sep 17 00:00:00 2001
From: Achim Schneider <achim@parity.io>
Date: Sat, 18 Mar 2023 17:27:53 +0100
Subject: [PATCH] no collect Vec

---
 primitives/arkworks/src/ed_on_bls12_377.rs | 14 ++++---------
 primitives/arkworks/src/ed_on_bls12_381.rs | 24 ++++++++--------------
 primitives/arkworks/src/utils.rs           | 24 +++++++++++-----------
 3 files changed, 24 insertions(+), 38 deletions(-)

diff --git a/primitives/arkworks/src/ed_on_bls12_377.rs b/primitives/arkworks/src/ed_on_bls12_377.rs
index 42510db851bec..82443b21a5b73 100644
--- a/primitives/arkworks/src/ed_on_bls12_377.rs
+++ b/primitives/arkworks/src/ed_on_bls12_377.rs
@@ -30,19 +30,13 @@ use sp_std::vec::Vec;
 pub fn msm(bases: Vec<u8>, scalars: Vec<u8>) -> Vec<u8> {
 	let bases: Vec<_> = bases
 		.chunks(twisted_edwards::Affine::<EdwardsConfig>::generator().serialized_size(Compress::No))
-		.into_iter()
-		.map(|a| {
-			deserialize_argument::<twisted_edwards::Affine<EdwardsConfig>>(a.collect::<Vec<_>>())
-		})
+		.into()
+		.map(|a| deserialize_argument::<twisted_edwards::Affine<EdwardsConfig>>(a))
 		.collect();
 	let scalars: Vec<_> = scalars
 		.chunks(<EdwardsConfig as CurveConfig>::ScalarField::zero().serialized_size(Compress::No))
-		.into_iter()
-		.map(|a| {
-			deserialize_argument::<<EdwardsConfig as CurveConfig>::ScalarField>(
-				a.collect::<Vec<_>>(),
-			)
-		})
+		.into()
+		.map(|a| deserialize_argument::<<EdwardsConfig as CurveConfig>::ScalarField>(a))
 		.collect();
 
 	let result = <EdwardsProjective as VariableBaseMSM>::msm(&bases, &scalars).unwrap();
diff --git a/primitives/arkworks/src/ed_on_bls12_381.rs b/primitives/arkworks/src/ed_on_bls12_381.rs
index 8decc6ec37eb1..3634099892bad 100644
--- a/primitives/arkworks/src/ed_on_bls12_381.rs
+++ b/primitives/arkworks/src/ed_on_bls12_381.rs
@@ -33,17 +33,13 @@ use sp_std::vec::Vec;
 pub fn te_msm(bases: Vec<u8>, scalars: Vec<u8>) -> Vec<u8> {
 	let bases: Vec<_> = bases
 		.chunks(TEAffine::<JubjubConfig>::generator().serialized_size(Compress::No))
-		.into_iter()
-		.map(|a| deserialize_argument::<TEAffine<JubjubConfig>>(a.collect::<Vec<_>>()))
+		.iter()
+		.map(|a| deserialize_argument::<TEAffine<JubjubConfig>>(a))
 		.collect();
 	let scalars: Vec<_> = scalars
 		.chunks(<JubjubConfig as CurveConfig>::ScalarField::zero().serialized_size(Compress::No))
-		.into_iter()
-		.map(|a| {
-			deserialize_argument::<<JubjubConfig as CurveConfig>::ScalarField>(
-				a.collect::<Vec<_>>(),
-			)
-		})
+		.iter()
+		.map(|a| deserialize_argument::<<JubjubConfig as CurveConfig>::ScalarField>(a))
 		.collect();
 
 	let result = <EdwardsProjective as VariableBaseMSM>::msm(&bases, &scalars).unwrap();
@@ -55,17 +51,13 @@ pub fn te_msm(bases: Vec<u8>, scalars: Vec<u8>) -> Vec<u8> {
 pub fn sw_msm(bases: Vec<u8>, scalars: Vec<u8>) -> Vec<u8> {
 	let bases: Vec<_> = bases
 		.chunks(SWAffine::<JubjubConfig>::genrator().serialized_size(Compress::No))
-		.into_iter()
-		.map(|a| deserialize_argument::<SWAffine<JubjubConfig>>(a.collect::<Vec<_>>()))
+		.iter()
+		.map(|a| deserialize_argument::<SWAffine<JubjubConfig>>(a))
 		.collect();
 	let scalars: Vec<_> = scalars
 		.chunks(<JubjubConfig as CurveConfig>::ScalarField::zero().serialized_size(Compress::No))
-		.into_iter()
-		.map(|a| {
-			deserialize_argument::<<JubjubConfig as CurveConfig>::ScalarField>(
-				a.collect::<Vec<_>>(),
-			)
-		})
+		.iter()
+		.map(|a| deserialize_argument::<<JubjubConfig as CurveConfig>::ScalarField>(a))
 		.collect();
 
 	let result = <SWProjective as VariableBaseMSM>::msm(&bases, &scalars).unwrap();
diff --git a/primitives/arkworks/src/utils.rs b/primitives/arkworks/src/utils.rs
index 4d0376992d263..df03f7318deb6 100644
--- a/primitives/arkworks/src/utils.rs
+++ b/primitives/arkworks/src/utils.rs
@@ -25,13 +25,13 @@ pub fn multi_miller_loop_generic<Curve: Pairing>(
 ) -> Result<Vec<u8>, PairingError> {
 	let g1: Vec<_> = a_vec
 		.chunks(<Curve as Pairing>::G1Affine::generator().serialized_size(Compress::No))
-		.into_iter()
-		.map(|elem| deserialize_argument::<<Curve as Pairing>::G1Affine>(elem.collect::<Vec<_>>()))
+		.iter()
+		.map(|elem| deserialize_argument::<<Curve as Pairing>::G1Affine>(elem))
 		.collect();
 	let g2: Vec<_> = b_vec
 		.chunks(<Curve as Pairing>::G2Affine::generator().serialized_size(Compress::No))
-		.into_iter()
-		.map(|elem| deserialize_argument::<<Curve as Pairing>::G2Affine>(elem.collect::<Vec<_>>()))
+		.iter()
+		.map(|elem| deserialize_argument::<<Curve as Pairing>::G2Affine>(elem))
 		.collect();
 
 	let result = Curve::multi_miller_loop(g1, g2);
@@ -55,13 +55,13 @@ pub fn final_exponentiation_generic<Curve: Pairing>(
 pub fn msm_g1_generic<Curve: Pairing>(bases: Vec<u8>, scalars: Vec<u8>) -> Vec<u8> {
 	let bases: Vec<_> = bases
 		.chunks(<Curve as Pairing>::G1Affine::generator().serialized_size(Compress::No))
-		.into_iter()
-		.map(|a| deserialize_argument::<<Curve as Pairing>::G1Affine>(a.collect::<Vec<_>>()))
+		.iter()
+		.map(|a| deserialize_argument::<<Curve as Pairing>::G1Affine>(a))
 		.collect();
 	let scalars: Vec<_> = scalars
 		.chunks(Curve::ScalarField::zero().serialized_size(Compress::No))
-		.into_iter()
-		.map(|a| deserialize_argument::<Curve::ScalarField>(a.collect::<Vec<_>>()))
+		.iter()
+		.map(|a| deserialize_argument::<Curve::ScalarField>(a))
 		.collect();
 
 	let result =
@@ -73,13 +73,13 @@ pub fn msm_g1_generic<Curve: Pairing>(bases: Vec<u8>, scalars: Vec<u8>) -> Vec<u
 pub fn msm_g2_generic<Curve: Pairing>(bases: Vec<u8>, scalars: Vec<u8>) -> Vec<u8> {
 	let bases: Vec<_> = bases
 		.chunks(<Curve as Pairing>::G2Affine::generator().serialized_size(Compress::No))
-		.into_iter()
-		.map(|a| deserialize_argument::<<Curve as Pairing>::G2Affine>(a.collect::<Vec<_>>()))
+		.iter()
+		.map(|a| deserialize_argument::<<Curve as Pairing>::G2Affine>(a))
 		.collect();
 	let scalars: Vec<_> = scalars
 		.chunks(Curve::ScalarField::zero().serialized_size(Compress::No))
-		.into_iter()
-		.map(|a| deserialize_argument::<Curve::ScalarField>(a.collect::<Vec<_>>()))
+		.iter()
+		.map(|a| deserialize_argument::<Curve::ScalarField>(a))
 		.collect();
 
 	let result =