Multiversion Versions Save

Fixed

• Fix is_{arch}_feature_detected path for non-x86.

Fixed

• Don't include unstable target features in targets = "simd".

Fixed

• Fixed handling patterns in match_target.

Changed

• The multiversion macro has been overhauled. Now uses a single attribute macro, rather than helper attributes.
• Increased minimum required Rust version to 1.61.0.

Added

• The function dispatch method is now selectable, between direct or indirect dispatch, as well as compile-time static dispatch.
• Added a variety of macros in the multiversion::target module for querying the selected target features.
• Targets can now be specified by CPU (e.g. x86-64-v2 or skylake).
• Added option to pass attributes to clones.
• Added special targets = "simd" option to automatically target all SIMD instruction sets.

Removed

• Removed the specialize mode. All targets now specify clones. Specialization should be implemented by querying the selected targets.
• Removed support for functions that reference self or Self. Previous support was inconsistent and difficult to use correctly.

Fixed

• Fixed broken impl Trait support. Using impl Trait in return position now results in an error.
• Dispatch is now bypassed in scenarios where no targets are specified for the target architecture, or if the first matching target features are known to exist at compile time.
• Improved performance of direct dispatch.
• Avoid indirect dispatch in some situations, such as when using retpolines

Fixed

• Fixed disallowing some valid architectures, such as "wasm32"

Added

• Added are_cpu_features_detected macro.
• Added #[crate_path] helper attribute for renaming/reimporting the crate.

Changed

• Changed runtime_dispatch Cargo feature to std
• Changed static dispatching from the #[static_dispatch] helper attribute to dispatch! helper macro.

Changed

• Removed dependency on regex and once_cell

Fixed

• Fixed bug where #[multiversion] failed to compile when crate was re-exported or renamed.

Added

• Support for associated functions (including methods).
• Support for impl Trait.
• Specification for name mangling.
• Documentation for #[safe_inner] helper attribute for #[target].

Removed

• Removed #[target_clones] attribute (functionality is now included in #[multiversion] attribute).

Changed

• #[multiversion] interface now uses helper attributes, providing both target specialization and function cloning.
• Increased minimum required Rust version to 1.34.0.

Fixed

• Vague error spans now point to a more informative source location.
• All errors now produce compile_error! instead of macro panics.

Added

• Cargo feature runtime_dispatch (enabled by default) which adds runtime CPU feature detection.
• #[no_std] support when the runtime_dispatch feature is disabled.

Fixed

• Fixed disallowing features with dots, such as sse4.2.

Added

• Conditional compilation with #[target_cfg] helper macro
• Support for const generics

Changed

• multiversion macro now requires unsafe to dispatch unsafe functions from safe functions

Fixed

• Fixed incorrect argument forwarding for destructured function arguments
• Static dispatch across modules now uses proper visibility
• Specifying architectures without features no longer results in compilation errors