ctutils 0.3.0

Constant-time utility library with selection and equality testing support targeting cryptographic applications. Supports `const fn` where appropriate. Built on the `cmov` crate which provides architecture-specific predication intrinsics. Heavily inspired by the `subtle` crate.
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# Changelog
All notable changes to this project will be documented in this file.

The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).

## 0.3.0 (2025-12-29)
### Removed
- `Choice::new` ([#1314])
- `(Partial)Eq` impls for `Choice` ([#1315])

[#1314]: https://github.com/RustCrypto/utils/pull/1314
[#1315]: https://github.com/RustCrypto/utils/pull/1315

## 0.2.3 (2025-12-29)
### Added
- Impl `From<u8>` for `Choice` ([#1309])
- `Choice::from_u8*` and `from_u16*` ([#1311])

### Changed
- Deprecate `Choice::new` ([#1312])

[#1309]: https://github.com/RustCrypto/utils/pull/1309
[#1311]: https://github.com/RustCrypto/utils/pull/1311
[#1312]: https://github.com/RustCrypto/utils/pull/1312

## 0.2.2 (2025-12-28)
### Added
- Unsigned `CtNeg` impls ([#1306])

[#1306]: https://github.com/RustCrypto/utils/pull/1306

## 0.2.1 (2025-12-27)
### Added
- Enhanced `subtle` interop ([#1289])

### Security
- Pin to `cmov` v0.4.3+ - includes important security fixes ([#1304])

[#1289]: https://github.com/RustCrypto/utils/pull/1304
[#1304]: https://github.com/RustCrypto/utils/pull/1304

## 0.2.0 (2025-12-27)
### Added
- Additional `Choice::from_u128*` constructors ([#1285])
- `CtNeg` trait ([#1286])

### Changed
- Renamed `Choice::from_*_nonzero` => `from_*_nz` ([#1287])

[#1285]: https://github.com/RustCrypto/utils/pull/1285
[#1286]: https://github.com/RustCrypto/utils/pull/1286
[#1287]: https://github.com/RustCrypto/utils/pull/1287

## 0.1.4 (2025-12-26)
### Added
- Impl `CtEq`/`CtSelect` for `isize` ([#1283])

[#1283]: https://github.com/RustCrypto/utils/pull/1283

## 0.1.3 (2025-12-26)
### Fixed
- Rustdoc syntax for variable-time-related warning text ([#1278])

[#1278]: https://github.com/RustCrypto/utils/pull/1278

## 0.1.2 (2025-12-26)
### Added
- Additional methods for `CtOption` ([#1274]):
  - `some`
  - `none`
  - `into_option_copied`
  - `filter_by`
  - `as_inner_unchecked`
  - `to_inner_unchecked`
- `Default` impl for `CtOption` ([#1274])
- `map!` and `unwrap_or!` macros ([#1274])
- `u128` methods for `Choice` ([#1277]):
  - `from_u128_le`
  - `from_u128_lsb`
  - `select_u128`

[#1274]: https://github.com/RustCrypto/utils/pull/1274
[#1277]: https://github.com/RustCrypto/utils/pull/1277

## 0.1.1 (2025-12-26)
### Added
- Additional `const fn` constructor and predication methods for `Choice` ([#1266], [#1272])

[#1266]: https://github.com/RustCrypto/utils/pull/1266
[#1272]: https://github.com/RustCrypto/utils/pull/1272

## 0.1.0 (2025-12-19)
- Initial release