A Rust hexadecimal decoding library

General purpose hex encoding/decoding library with a conservative MSRV and dependency policy.

You're currently looking at the stable crate which has advanced features removed to make stabilization quicker and thus allowing downstream crates to stabilize quicker too. To get the full feature set check the lower (0.x.y) versions. Read Stabilization strategy section for more information.

Stabilization strategy

Because downstream crates may need to return hex errors in their APIs and they need to be stabilized soon, this crate only exposes the errors and two basic decoding functions. This should already help with the vast majority of the cases and we're sufficiently confident that these errors won't have a breaking change any time soon (possibly never).

If you're writing a binary you don't need to worry about any of this and just use the unstable version for now. If you're writing a library you should use these stable errors in the API but you may internally depend on the unstable crate version to get the advanced features that won't affect your API. This way your API can stabilize before all features in this crate are fully stable and you still can use all of them.

Crate feature flags

• std - enables the standard library, on by default.
• alloc - enables features that require allocation such as decoding into Vec<u8>, implied by std.
• newer-rust-version - enables Rust version detection and thus newer features, may add dependency on a feature detection crate to reduce compile times. This feature is expected to do nothing once the native detection is in Rust and our MSRV is at least that version. We may also remove the feature gate in 2.0 with semver trick once that happens.

Minimum Supported Rust Version (MSRV)

This library should compile with almost any combination of features on Rust 1.63.0, however we reserve the right to use features to guard compiler specific code so --all-features may not work using the MSRV toolchain.

Policy

We don't intend to bump MSRV until the newer Rust version is at least two years old and also included in Debian stable (1.63 is in Debian 12 at the moment).

Note though that the dependencies may have looser policy. This is not considered breaking/wrong - you would just need to pin them in Cargo.lock (not .toml).