bitvec

Notes

Performance regressions have been reported between the development series 0.20 onwards and 1.0. It appears at least some of these regressions are due to the removal of the #[inline] attribute on bitvec public functions.

This attribute has been applied to all bitvec functions. You may see regressions in size of your final artifact, but you should also see improvements in your runtime speed. This is being tracked in [sharksforarms/deku#246].

Changes

• The bits![static mut …] invocation has been made unsafe at the invocation site, in response to [Issue #156] filed by GitHub user [@SimonSapin].

  This is technically an API break (formerly safe code now requires an unsafe block) but as no run-time behavior or compile-time types have changed except for this, and Rust considers breaking incorrect code to be acceptable within SemVer patches, I am publishing it as a patch.

• GitHub user [@dtolnay] fixed incorrect serde behaviors in [Pull Request #185]. This behavior was first reported in [Issue #167] by GitHub user [@Nelarius].

• Compilation no longer depends on environment variables set by Cargo, as requested in [Pull Request #162] by GitHub user [@rocallahan].

• The bitvec![val; len] macro can again take len as a runtime value as well as a compile-time constant. [Pull Request #160] was provided by GitHub user [@coolreader18].

• The return types of slice::Iter::by_{refs,vals} are restored to named types, rather than impl Iterator... opaque types. This allows them to be used directly in other sites. This defect was reported in [Issue #169] by GitHub user [@dignifiedquire].

🚨 THIS IS A BREAKING CHANGE RELEASE! 🚨

Your code has broken. You will need to change it in order to use this. This work on your part is worth it.

This release has a great deal of changes from the 0.22 development series! Most breaking changes should have reasonable error messages indicating how they can be repaired.

Removed APIs do not have deprecation notices! Use of removed APIs will fail to compile. You must check this changelog, or the crate documentation, to find out appropriate replacements.

Type Parameter Reördering

The <O, T> type parameter pair that has existed since 0.10 is reversed to be <T, O>! This will cause all of your type definitions to fail, as suddenly all of your chosen type arguments do not satisfy the demanded traits.

This change was made in accordance with [Issue #136], requested by GitHub user [@changhe3].

Additional Changes

• The MSRV is raised to 1.56.
• BitField now supports signed integers! BitMemory is completely removed.
• BitSlice::from_slice{,_mut} are now infallible constructors, and panic when the source is too long. The original fallible behavior is renamed to BitSlice::try_from_slice{,_mut}.
• the {Bit,}DomainMut types have been removed. The {Bit,}Domain types now take a Mutability type parameter instead. The .{bit_,}domain{,_mut}() methods on BitSlice exist as normal, but have changed their return types to specify a Const or Mut type parameter rather than {Bit,}Domain or {Bit,}DomainMut, respectively.
• Iter::by_{ref,val} are renamed to by_{ref,val}s, to prevent collision with Iterator::by_ref.
• The long-standing behavior of the &=, |=, and ^= operators has been changed! They now operate directly on data structures, rather than routing through iterators. If you want to perform boolean arithmetic using arbitrary bool streams, use iterator combinators like .iter_mut().zip(stream).for_each(|(mut orig, new)| *orig ^= new). This change allows the arithmetic implementations to be accelerated when working between bit-slices of equal types.
• BitSlice::set_all is removed, as the standard-library API [T]::fill replaces it.
• BitSlice::offset_from is removed. Use .as_bitptr().offset_from().
• BitSlice::as_raw_slice is removed. Use .domain() to access the underlying memory.

Documentation

Module and type documentation have been lifted into the doc/ tree as Markdown files. The [user guide], in book/ has been more thoroughly rewritten.

Please file any problems or confusions about the documentation as an issue! The documentation is a project artifact equally, if not more, important as the Rust library.

Dependency Raises

As part of the migration of incidental logic out of bitvec, the following utility libraries have been updated:

• funty 2.0 provides a more comprehensive coverage of the language primitives.
• wyz 0.5 contains more logic formerly in the utility module, as well as a stronger system for generalizing over references.

Version 0 (Prototyping)

bitvec’s first three and a half years of development used the zero-dot series as it explored its behavior. These versions are now deprecated and will not receive further support. They are listed only in summary, and may be removed from crates.io in the future.