feat: no_std

CHANGELOG.md

@@ -9,6 +9,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- Support for `no_std` environments (#274)
+
+[#274]: https://github.com/recmo/uint/pulls/274
+
 ## [1.9.0] - 2023-07-25
 
 ### Added

Cargo.toml

@@ -42,26 +42,29 @@ path = "benches/bench.rs"
 [dependencies]
 ruint-macro.workspace = true
 
-thiserror = "1.0"
+thiserror = { version = "1.0", optional = true }
 
 # support
-alloy-rlp = { version = "0.3", optional = true }
-arbitrary = { version = "1", optional = true }
-ark-ff-04 = { version = "0.4.0", package = "ark-ff", optional = true }
-ark-ff-03 = { version = "0.3.0", package = "ark-ff", optional = true }
-bn-rs = { version = "0.2", optional = true }
-fastrlp = { version = "0.3", optional = true }
-num-bigint = { version = "0.4", optional = true }
-parity-scale-codec = { version = "3", optional = true, features = ["derive", "max-encoded-len"] }
-primitive-types = { version = "0.12", optional = true }
-proptest = { version = "1", optional = true }
-pyo3 = { version = "0.19", optional = true }
-quickcheck = { version = "1", optional = true }
-rand = { version = "0.8", optional = true }
-rlp = { version = "0.5", optional = true }
-serde = { version = "1", optional = true }
-valuable = { version = "0.1", optional = true }
-zeroize = { version = "1.6", optional = true }
+alloy-rlp = { version = "0.3", optional = true, default-features = false }
+arbitrary = { version = "1", optional = true, default-features = false }
+ark-ff-03 = { version = "0.3.0", package = "ark-ff", optional = true, default-features = false }
+ark-ff-04 = { version = "0.4.0", package = "ark-ff", optional = true, default-features = false }
+bn-rs = { version = "0.2", optional = true, default-features = true }
+fastrlp = { version = "0.3", optional = true, default-features = false }
+num-bigint = { version = "0.4", optional = true, default-features = false }
+parity-scale-codec = { version = "3", optional = true, features = [
+    "derive",
+    "max-encoded-len",
+], default-features = false }
+primitive-types = { version = "0.12", optional = true, default-features = false }
+proptest = { version = "1", optional = true, default-features = false }
+pyo3 = { version = "0.19", optional = true, default-features = false }
+quickcheck = { version = "1", optional = true, default-features = false }
+rand = { version = "0.8", optional = true, default-features = false }
+rlp = { version = "0.5", optional = true, default-features = false }
+serde = { version = "1", optional = true, default-features = false }
+valuable = { version = "0.1", optional = true, default-features = false }
+zeroize = { version = "1.6", optional = true, default-features = false }
 
 # postgres
 bytes = { version = "1.4", optional = true }
@@ -73,8 +76,8 @@ sqlx-core = { version = "0.7", optional = true }
 [dev-dependencies]
 ruint = { workspace = true, features = ["arbitrary", "proptest"] }
 
-ark-bn254-04 = { version = "0.4.0", package = "ark-bn254" }
 ark-bn254-03 = { version = "0.3.0", package = "ark-bn254" }
+ark-bn254-04 = { version = "0.4.0", package = "ark-bn254" }
 
 criterion = "0.5"
 rand = "0.8"
@@ -89,28 +92,47 @@ proptest = "1.2"
 serde_json = "1.0"
 
 [features]
+default = ["std"]
+std = [
+    "thiserror",
+    "alloy-rlp?/std",
+    "ark-ff-03?/std",
+    "ark-ff-04?/std",
+    "bytes?/std",
+    "fastrlp?/std",
+    "num-bigint?/std",
+    "parity-scale-codec?/std",
+    "primitive-types?/std",
+    "proptest?/std",
+    "rand?/std",
+    "rlp?/std",
+    "serde?/std",
+    "valuable?/std",
+    "zeroize?/std",
+]
+
 # nightly-only features
 nightly = []
 generic_const_exprs = ["nightly"]
 
 # support
 alloy-rlp = ["dep:alloy-rlp"]
-arbitrary = ["dep:arbitrary"]
+arbitrary = ["dep:arbitrary", "std"]
 ark-ff = ["dep:ark-ff-03"]
 ark-ff-04 = ["dep:ark-ff-04"]
-bn-rs = ["dep:bn-rs"]
+bn-rs = ["dep:bn-rs", "std"]
 fastrlp = ["dep:fastrlp"]
 num-bigint = ["dep:num-bigint"]
 parity-scale-codec = ["dep:parity-scale-codec"]
 primitive-types = ["dep:primitive-types"]
 proptest = ["dep:proptest"]
-pyo3 = ["dep:pyo3"]
-quickcheck = ["dep:quickcheck"]
+pyo3 = ["dep:pyo3", "std"]
+quickcheck = ["dep:quickcheck", "std"]
 rand = ["dep:rand"]
 rlp = ["dep:rlp"]
 serde = ["dep:serde"]
 valuable = ["dep:valuable"]
 zeroize = ["dep:zeroize"]
 
-postgres = ["dep:postgres-types", "dep:bytes"]
-sqlx = ["dep:sqlx-core"]
+postgres = ["dep:postgres-types", "dep:bytes", "std"]
+sqlx = ["dep:sqlx-core", "std"]

benches/benches/algorithms/gcd.rs

@@ -1,6 +1,6 @@
 use crate::prelude::*;
+use core::cmp::{max, min};
 use ruint::algorithms::LehmerMatrix as Matrix;
-use std::cmp::{max, min};
 
 pub fn group(criterion: &mut Criterion) {
     bench_from_u64(criterion);

benches/benches/log.rs

@@ -1,12 +1,16 @@
 use crate::prelude::*;
 
 pub fn group(criterion: &mut Criterion) {
+    #[cfg(not(feature = "std"))]
+    let _ = criterion;
+    #[cfg(feature = "std")]
     const_for!(BITS in BENCH {
         const LIMBS: usize = nlimbs(BITS);
         bench_log::<BITS, LIMBS>(criterion);
     });
 }
 
+#[cfg(feature = "std")]
 fn bench_log<const BITS: usize, const LIMBS: usize>(criterion: &mut Criterion) {
     if BITS < 7 {
         return;

benches/benches/root.rs

@@ -1,6 +1,9 @@
 use crate::prelude::*;
 
 pub fn group(criterion: &mut Criterion) {
+    #[cfg(not(feature = "std"))]
+    let _ = criterion;
+    #[cfg(feature = "std")]
     const_for!(BITS in BENCH {
         const LIMBS: usize = nlimbs(BITS);
         bench_root::<BITS, LIMBS>(criterion, 2);
@@ -10,6 +13,7 @@ pub fn group(criterion: &mut Criterion) {
     });
 }
 
+#[cfg(feature = "std")]
 fn bench_root<const BITS: usize, const LIMBS: usize>(criterion: &mut Criterion, degree: usize) {
     let input = Uint::<BITS, LIMBS>::arbitrary();
     let mut runner = TestRunner::deterministic();

ruint-macro/src/lib.rs

@@ -1,11 +1,11 @@
 #![doc = include_str!("../README.md")]
 #![warn(clippy::all, clippy::pedantic, clippy::cargo, clippy::nursery)]
 
-use proc_macro::{Delimiter, Group, Ident, Literal, Punct, Spacing, Span, TokenStream, TokenTree};
-use std::{
+use core::{
     fmt::{Display, Formatter, Write},
     str::FromStr,
 };
+use proc_macro::{Delimiter, Group, Ident, Literal, Punct, Spacing, Span, TokenStream, TokenTree};
 
 #[derive(Copy, Clone, PartialEq, Debug)]
 enum LiteralBaseType {

src/algorithms/div/knuth.rs

@@ -194,11 +194,12 @@ mod tests {
         add::{cmp, sbb_n},
         addmul,
     };
+    use alloc::vec::Vec;
+    use core::cmp::Ordering;
     use proptest::{
         collection, num, proptest,
         strategy::{Just, Strategy},
     };
-    use std::cmp::Ordering;
 
     // Basic test without exceptional paths
     #[test]

src/algorithms/div/reciprocal.rs

@@ -6,7 +6,7 @@
 //! [new]: https://gmplib.org/list-archives/gmp-devel/2019-October/005590.html
 #![allow(dead_code, clippy::cast_possible_truncation, clippy::cast_lossless)]
 
-use std::num::Wrapping;
+use core::num::Wrapping;
 
 pub use self::{reciprocal_2_mg10 as reciprocal_2, reciprocal_mg10 as reciprocal};
 

src/algorithms/gcd/matrix.rs

@@ -336,9 +336,9 @@ mod tests {
     use core::{
         cmp::{max, min},
         mem::swap,
+        str::FromStr,
     };
     use proptest::{proptest, test_runner::Config};
-    use std::str::FromStr;
 
     fn gcd(mut a: u128, mut b: u128) -> u128 {
         while b != 0 {

src/algorithms/gcd/mod.rs

@@ -193,7 +193,7 @@ mod tests {
 
     #[test]
     fn test_gcd_one() {
-        use std::str::FromStr;
+        use core::str::FromStr;
         const BITS: usize = 129;
         const LIMBS: usize = nlimbs(BITS);
         type U = Uint<BITS, LIMBS>;

src/base_convert.rs

@@ -1,24 +1,39 @@
 use crate::Uint;
-use thiserror::Error;
+use alloc::vec::Vec;
+use core::fmt;
 
 /// Error for [`from_base_le`][Uint::from_base_le] and
 /// [`from_base_be`][Uint::from_base_be].
 #[allow(clippy::module_name_repetitions)]
-#[derive(Clone, Copy, Debug, PartialEq, Eq, Error)]
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
 pub enum BaseConvertError {
     /// The value is too large to fit the target type.
-    #[error("The value is too large to fit the target type")]
     Overflow,
 
     /// The requested number base `.0` is less than two.
-    #[error("The requested number base {0} is less than two")]
     InvalidBase(u64),
 
     /// The provided digit `.0` is out of range for requested base `.1`.
-    #[error("digit {0} is out of range for base {1}")]
     InvalidDigit(u64, u64),
 }
 
+#[cfg(feature = "std")]
+impl std::error::Error for BaseConvertError {}
+
+impl fmt::Display for BaseConvertError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::Overflow => write!(f, "The value is too large to fit the target type"),
+            Self::InvalidBase(base) => {
+                write!(f, "The requested number base {base} is less than two")
+            }
+            Self::InvalidDigit(digit, base) => {
+                write!(f, "digit {digit} is out of range for base {base}")
+            }
+        }
+    }
+}
+
 impl<const BITS: usize, const LIMBS: usize> Uint<BITS, LIMBS> {
     /// Returns an iterator over the base `base` digits of the number in
     /// little-endian order.
@@ -68,6 +83,7 @@ impl<const BITS: usize, const LIMBS: usize> Uint<BITS, LIMBS> {
         base: u64,
         digits: I,
     ) -> Result<Self, BaseConvertError> {
+        // TODO: Do not allocate.
         let mut digits: Vec<_> = digits.into_iter().collect();
         digits.reverse();
         Self::from_base_be(base, digits)

src/bit_arr.rs

@@ -1,9 +1,12 @@
 use crate::{ParseError, Uint};
-use core::ops::{
-    BitAnd, BitAndAssign, BitOr, BitOrAssign, BitXor, BitXorAssign, Index, Not, Shl, ShlAssign,
-    Shr, ShrAssign,
+use alloc::{borrow::Cow, vec::Vec};
+use core::{
+    ops::{
+        BitAnd, BitAndAssign, BitOr, BitOrAssign, BitXor, BitXorAssign, Index, Not, Shl, ShlAssign,
+        Shr, ShrAssign,
+    },
+    str::FromStr,
 };
-use std::{borrow::Cow, str::FromStr};
 
 /// A newtype wrapper around [`Uint`] that restricts operations to those
 /// relevant for bit arrays.

src/bytes.rs

@@ -5,11 +5,11 @@ use crate::{
     utils::{trim_end_slice, trim_end_vec},
     Uint,
 };
+use alloc::{borrow::Cow, vec::Vec};
 use core::{
     ptr::{addr_of, addr_of_mut},
     slice,
 };
-use std::borrow::Cow;
 
 // OPT: *_to_smallvec to avoid allocation.
 impl<const BITS: usize, const LIMBS: usize> Uint<BITS, LIMBS> {