Add no-std support via a default-enabled std feature flag

CHANGELOG.md

@@ -7,6 +7,9 @@ and this project adheres to Rust's notion of
 
 ## [Unreleased]
 
+### Changed
+- Migrated to `nonempty 0.11`.
+
 ## [0.10.1] - 2024-12-16
 
 ### Added

Cargo.toml

@@ -36,7 +36,7 @@ pasta_curves = "0.5"
 proptest = { version = "1.0.0", optional = true }
 rand = { version = "0.8", default-features = false }
 reddsa = { version = "0.5", default-features = false }
-nonempty = "0.7"
+nonempty = { version = "0.11", default-features = false }
 poseidon = { package = "halo2_poseidon", version = "0.1" }
 serde = { version = "1.0", default-features = false, features = ["derive"] }
 sinsemilla = "0.1"
@@ -81,8 +81,9 @@ pprof = { version = "0.11", features = ["criterion", "flamegraph"] }
 bench = false
 
 [features]
-default = ["circuit", "multicore"]
-circuit = ["dep:halo2_gadgets", "dep:halo2_proofs", "core2/std", "group/wnaf-memuse", "reddsa/std"]
+default = ["circuit", "multicore", "std"]
+std = ["core2/std", "group/wnaf-memuse", "reddsa/std"]
+circuit = ["dep:halo2_gadgets", "dep:halo2_proofs", "std"]
 unstable-frost = []
 multicore = ["halo2_proofs?/multicore"]
 dev-graph = ["halo2_proofs?/dev-graph", "image", "plotters"]

src/builder.rs

@@ -163,6 +163,7 @@ impl fmt::Display for BuildError {
     }
 }
 
+#[cfg(feature = "std")]
 impl std::error::Error for BuildError {}
 
 #[cfg(feature = "circuit")]
@@ -200,6 +201,7 @@ impl fmt::Display for SpendError {
     }
 }
 
+#[cfg(feature = "std")]
 impl std::error::Error for SpendError {}
 
 /// The only error that can occur here is if outputs are disabled for this builder.
@@ -212,6 +214,7 @@ impl fmt::Display for OutputError {
     }
 }
 
+#[cfg(feature = "std")]
 impl std::error::Error for OutputError {}
 
 /// Information about a specific note to be spent in an [`Action`].

src/bundle.rs

@@ -12,10 +12,12 @@ pub use batch::BatchValidator;
 use core::fmt;
 
 use blake2b_simd::Hash as Blake2bHash;
-use memuse::DynamicUsage;
 use nonempty::NonEmpty;
 use zcash_note_encryption::{try_note_decryption, try_output_recovery_with_ovk};
 
+#[cfg(feature = "std")]
+use memuse::DynamicUsage;
+
 use crate::{
     action::Action,
     address::Address,
@@ -474,6 +476,7 @@ impl<V> Bundle<Authorized, V> {
     }
 }
 
+#[cfg(feature = "std")]
 impl<V: DynamicUsage> DynamicUsage for Bundle<Authorized, V> {
     fn dynamic_usage(&self) -> usize {
         self.actions.tail.dynamic_usage()

src/keys.rs

@@ -682,7 +682,7 @@ impl IncomingViewingKey {
 #[derive(Clone, Debug)]
 pub struct PreparedIncomingViewingKey(PreparedNonZeroScalar);
 
-#[cfg(feature = "circuit")]
+#[cfg(feature = "std")]
 impl memuse::DynamicUsage for PreparedIncomingViewingKey {
     fn dynamic_usage(&self) -> usize {
         self.0.dynamic_usage()

src/lib.rs

@@ -16,79 +16,80 @@
 #![deny(missing_debug_implementations)]
 #![deny(missing_docs)]
 #![deny(unsafe_code)]
 
 #[macro_use]
 extern crate alloc;
 
+#[cfg(feature = "std")]
 extern crate std;
 
 use alloc::vec::Vec;
 
 mod action;
 mod address;
 pub mod builder;
 pub mod bundle;
 #[cfg(feature = "circuit")]
 pub mod circuit;
 mod constants;
 pub mod keys;
 pub mod note;
 pub mod note_encryption;
 pub mod pczt;
 pub mod primitives;
 mod spec;
 pub mod tree;
 pub mod value;
 pub mod zip32;
 
 #[cfg(test)]
 mod test_vectors;
 
 pub use action::Action;
 pub use address::Address;
 pub use bundle::Bundle;
 pub use constants::MERKLE_DEPTH_ORCHARD as NOTE_COMMITMENT_TREE_DEPTH;
 pub use note::Note;
 pub use tree::Anchor;
 
 /// A proof of the validity of an Orchard [`Bundle`].
 ///
 /// [`Bundle`]: crate::bundle::Bundle
 #[derive(Clone)]
 pub struct Proof(Vec<u8>);
 
 impl core::fmt::Debug for Proof {
     fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
         if f.alternate() {
             f.debug_tuple("Proof").field(&self.0).finish()
         } else {
             // By default, only show the proof length, not its contents.
             f.debug_tuple("Proof")
                 .field(&format_args!("{} bytes", self.0.len()))
                 .finish()
         }
     }
 }
 
 impl AsRef<[u8]> for Proof {
     fn as_ref(&self) -> &[u8] {
         &self.0
     }
 }
 
 impl memuse::DynamicUsage for Proof {
     fn dynamic_usage(&self) -> usize {
         self.0.dynamic_usage()
     }
 
     fn dynamic_usage_bounds(&self) -> (usize, Option<usize>) {
         self.0.dynamic_usage_bounds()
     }
 }
 
 impl Proof {
     /// Constructs a new Proof value.
     pub fn new(bytes: Vec<u8>) -> Self {
         Proof(bytes)
     }
 }

src/primitives/redpallas.rs

@@ -5,7 +5,7 @@ use core::cmp::{Ord, Ordering, PartialOrd};
 use pasta_curves::pallas;
 use rand::{CryptoRng, RngCore};
 
-#[cfg(feature = "circuit")]
+#[cfg(feature = "std")]
 pub use reddsa::batch;
 
 #[cfg(test)]
@@ -127,7 +127,7 @@ impl VerificationKey<SpendAuth> {
     }
 
     /// Creates a batch validation item from a `SpendAuth` signature.
-    #[cfg(feature = "circuit")]
+    #[cfg(feature = "std")]
     pub fn create_batch_item<M: AsRef<[u8]>>(
         &self,
         sig: Signature<SpendAuth>,
@@ -137,7 +137,7 @@ impl VerificationKey<SpendAuth> {
     }
 }
 
-#[cfg(feature = "circuit")]
+#[cfg(feature = "std")]
 impl VerificationKey<Binding> {
     /// Creates a batch validation item from a `Binding` signature.
     pub fn create_batch_item<M: AsRef<[u8]>>(

src/spec.rs

@@ -7,7 +7,7 @@ use ff::{Field, FromUniformBytes, PrimeField, PrimeFieldBits};
 use group::{Curve, Group, GroupEncoding, WnafBase, WnafScalar};
 #[cfg(feature = "circuit")]
 use halo2_gadgets::{poseidon::primitives as poseidon, sinsemilla::primitives as sinsemilla};
-#[cfg(feature = "circuit")]
+#[cfg(feature = "std")]
 use memuse::DynamicUsage;
 use pasta_curves::{
     arithmetic::{CurveAffine, CurveExt},
@@ -157,7 +157,7 @@ impl PreparedNonIdentityBase {
 #[derive(Clone, Debug)]
 pub(crate) struct PreparedNonZeroScalar(WnafScalar<pallas::Scalar, PREPARED_WINDOW_SIZE>);
 
-#[cfg(feature = "circuit")]
+#[cfg(feature = "std")]
 impl DynamicUsage for PreparedNonZeroScalar {
     fn dynamic_usage(&self) -> usize {
         self.0.dynamic_usage()

src/value.rs

@@ -81,6 +81,7 @@ impl fmt::Display for OverflowError {
     }
 }
 
+#[cfg(feature = "std")]
 impl std::error::Error for OverflowError {}
 
 /// The non-negative value of an individual Orchard note.