fix: add alloc features in no_std

README.md

@@ -30,4 +30,9 @@ foundry.
 cargo clippy --no-default-features
 cargo clippy
 cargo clippy --target wasm32-unknown-unknown
-cargo clippy --features eip712-serde
+cargo clippy --all-features
+
+# Note on `no_std`
+
+We try to support `no_std` with `alloc`. These crates will work in environments
+without standard, as long as the `alloc` crate exists.

abi/Cargo.toml

@@ -17,7 +17,7 @@ repository.workspace = true
 ethers-primitives.workspace = true
 sol-type-parser.workspace = true
 
-hex.workspace = true
+hex = { workspace = true, features = ["alloc"] }
 tiny-keccak = { workspace = true, features = ["keccak"] }
 
 thiserror = { workspace = true, optional = true }
@@ -27,7 +27,7 @@ serde = { workspace = true, optional = true }
 hex-literal.workspace = true
 
 [features]
-default = ["std"]
+default = ["std", "hex/alloc"]
 std = ["ethers-primitives/std", "hex/std", "serde?/std", "thiserror"]
 # TODO: Can we remove std from here?
 eip712-serde = ["std", "dep:serde"]

abi/src/sol_types/sol_type.rs

@@ -3,7 +3,7 @@ use core::marker::PhantomData;
 use ethers_primitives::{B160, I256, U256};
 
 #[cfg(not(feature = "std"))]
-use crate::no_std_prelude::{Borrow, String as RustString, ToOwned, ToString, Vec};
+use crate::no_std_prelude::{Borrow, String as RustString, ToOwned, Vec};
 #[cfg(feature = "std")]
 use std::{borrow::Borrow, string::String as RustString};
 

dyn-abi/Cargo.toml

@@ -19,7 +19,7 @@ ethers-primitives.workspace = true
 
 hex.workspace = true
 serde.workspace = true
-serde_json.workspace = true
+serde_json = { workspace = true, features = ["alloc"] }
 
 [features]
 default = ["std"]