From 15e9fffaa675670d66c89ff46d02b9e2ad657871 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timoth=C3=A9e=20Delabrouille?=
 <timothee.delabrouille@gmail.com>
Date: Thu, 21 Dec 2023 15:47:16 +0100
Subject: [PATCH] fix: improve the alloc feature in types-core

---
 crates/starknet-types-core/Cargo.toml      |  6 ++--
 crates/starknet-types-core/src/felt/mod.rs | 36 ++++++++++++++++------
 crates/starknet-types-rpc/Cargo.toml       |  2 +-
 ensure_no_std/src/main.rs                  |  2 ++
 4 files changed, 32 insertions(+), 14 deletions(-)

diff --git a/crates/starknet-types-core/Cargo.toml b/crates/starknet-types-core/Cargo.toml
index 3bbfbbf..01a451e 100644
--- a/crates/starknet-types-core/Cargo.toml
+++ b/crates/starknet-types-core/Cargo.toml
@@ -23,7 +23,7 @@ lazy_static = { version = "1.4.0", default-features = false, features = [
 
 # Optional
 arbitrary = { version = "1.3.0", optional = true }
-serde = { version = "1.0.163", optional = true, default-features = false }
+serde = { version = "1.0.163", optional = true, default-features = false, features = ["alloc"] }
 lambdaworks-crypto = { version = "0.3.0", default-features = false, optional = true }
 parity-scale-codec = { version = "3.2.2", default-features = false, optional = true }
 
@@ -37,13 +37,13 @@ std = [
   "num-integer/std",
   "serde?/std",
 ]
+alloc = []
 curve = []
 hash = ["dep:lambdaworks-crypto"]
 arbitrary = ["std", "dep:arbitrary"]
 parity-scale-codec = ["dep:parity-scale-codec"]
-serde = ["dep:serde"]
+serde = ["alloc", "dep:serde"]
 num-traits = []
-alloc = ["serde?/alloc"]
 
 [dev-dependencies]
 proptest = "1.1.0"
diff --git a/crates/starknet-types-core/src/felt/mod.rs b/crates/starknet-types-core/src/felt/mod.rs
index 0cfbcf2..5b76705 100644
--- a/crates/starknet-types-core/src/felt/mod.rs
+++ b/crates/starknet-types-core/src/felt/mod.rs
@@ -27,12 +27,9 @@ pub type BitArrayStore = [u64; 4];
 #[cfg(not(target_pointer_width = "64"))]
 pub type BitArrayStore = [u32; 8];
 
+#[cfg(any(test, feature = "alloc"))]
 pub extern crate alloc;
 
-use alloc::string::ToString;
-#[cfg(not(target_pointer_width = "64"))]
-use alloc::vec::Vec;
-
 use lambdaworks_math::{
     field::{
         element::FieldElement, fields::fft_friendly::stark_252_prime_field::Stark252PrimeField,
@@ -200,16 +197,26 @@ impl Felt {
 
     /// Converts to big-endian bit representation.
     /// This is as performant as [to_bits_le](Felt::to_bits_le)
+    #[cfg(target_pointer_width = "64")]
+    pub fn to_bits_be(&self) -> BitArray<BitArrayStore> {
+        let mut limbs = self.0.representative().limbs;
+        limbs.reverse();
+
+        BitArray::new(limbs)
+    }
+
+    /// Converts to big-endian bit representation.
+    /// This is as performant as [to_bits_le](Felt::to_bits_le)
+    #[cfg(all(feature = "alloc", not(target_pointer_width = "64")))]
     pub fn to_bits_be(&self) -> BitArray<BitArrayStore> {
         let mut limbs = self.0.representative().limbs;
         limbs.reverse();
 
-        #[cfg(not(target_pointer_width = "64"))]
         // Split limbs to adjust to BitArrayStore = [u32; 8]
         let limbs: [u32; 8] = limbs
             .into_iter()
             .flat_map(|n| [(n >> 32) as u32, n as u32])
-            .collect::<Vec<u32>>()
+            .collect::<alloc::vec::Vec<u32>>()
             .try_into()
             .unwrap();
 
@@ -225,15 +232,24 @@ impl Felt {
 
     /// Converts to little-endian bit representation.
     /// This is as performant as [to_bits_be](Felt::to_bits_be)
+    #[cfg(target_pointer_width = "64")]
+    pub fn to_bits_le(&self) -> BitArray<BitArrayStore> {
+        let limbs = self.0.representative().limbs;
+
+        BitArray::new(limbs)
+    }
+
+    /// Converts to little-endian bit representation.
+    /// This is as performant as [to_bits_be](Felt::to_bits_be)
+    #[cfg(all(feature = "alloc", not(target_pointer_width = "64")))]
     pub fn to_bits_le(&self) -> BitArray<BitArrayStore> {
         let limbs = self.0.representative().limbs;
 
-        #[cfg(not(target_pointer_width = "64"))]
         // Split limbs to adjust to BitArrayStore = [u32; 8]
         let limbs: [u32; 8] = limbs
             .into_iter()
             .flat_map(|n| [n as u32, (n >> 32) as u32])
-            .collect::<Vec<u32>>()
+            .collect::<alloc::vec::Vec<u32>>()
             .try_into()
             .unwrap();
 
@@ -929,13 +945,13 @@ mod formatting {
     }
 
     /// Represents [Felt] in uppercase hexadecimal format.
+    #[cfg(feature = "alloc")]
     impl fmt::UpperHex for Felt {
         fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
             write!(
                 f,
                 "0x{}",
-                self.0
-                    .to_string()
+                alloc::string::ToString::to_string(&self.0)
                     .strip_prefix("0x")
                     .unwrap()
                     .to_uppercase()
diff --git a/crates/starknet-types-rpc/Cargo.toml b/crates/starknet-types-rpc/Cargo.toml
index 4760201..38ae114 100644
--- a/crates/starknet-types-rpc/Cargo.toml
+++ b/crates/starknet-types-rpc/Cargo.toml
@@ -16,7 +16,7 @@ default = ["std"]
 std = ["serde/std", "starknet-types-core/std"]
 
 [dependencies]
-starknet-types-core = { path = "../starknet-types-core", default-features = false, features = ["serde", "alloc"] }
+starknet-types-core = { path = "../starknet-types-core", default-features = false, features = ["serde"] }
 serde = { version = "1", default-features = false, features = ["derive"] }
 
 [dev-dependencies]
diff --git a/ensure_no_std/src/main.rs b/ensure_no_std/src/main.rs
index ae94696..3f94bd6 100644
--- a/ensure_no_std/src/main.rs
+++ b/ensure_no_std/src/main.rs
@@ -19,3 +19,5 @@ static ALLOC: wee_alloc::WeeAlloc = wee_alloc::WeeAlloc::INIT;
 
 #[allow(unused_imports)]
 use starknet_types_core;
+#[allow(unused_imports)]
+use starknet_types_rpc;