Accept July 31st as a valid date

I plan to yank old versions without this fix.

Fixed

• Relax day-of-month validation, so date 2026-07-31 is accepted (fixes issue #10).

Backport date fixes from v0.3.1

I plan to yank old versions without this fix.

Fixed

• Relax day-of-month validation, so date 2026-07-31 is accepted (fixes [issue #10]).
  Backported from release v0.3.1.

Remove deprecated maybe_const_fn! macro

Removed

• BREAKING: Remove deprecated maybe_const_fn! macro.
  • Remove compat-maybe-const-fn feature, which is now unnecessary.
  • Eliminates our only dependency.

NOTE: Although promised in an early draft, using semver-trick would be counterproductive.

Pull changes from rustversion v1.0.23.

rustversion logic update

Updated version detection logic to mirror rustversion v1.0.23 (previously v1.0.17).

This includes the following changes:

• Support for the mirai compiler wrapper.
• Set RUSTVERSION=1 during rustc --version command (fixes rustversion#67)

Note that only changes to sources in the build/ subdirectory of rustversion
are actually applicable to rustversion-detect.
Even then, some changes are not needed here (ex. no need to workaround -Zfmt-debug=none).

Added

• Add #[must_use] annotations to most public methods.

Split maybe_const_fn! into its own crate.

Changes

• The maybe_const_fn! macro has been moved to its own crate.
  For compatibility reasons, this macro is re-exported from the rustversion-detect crate (but still deprecated)
  • It is possible to disable this re-exporting and remove the dependency by turning off the default feature compat-maybe-const-fn.
• Improved crate-level documentation and README.

Removed

• Hide documentation for deprecated maybe_const_fn! macro.

Move version detection to runtime

Avoids the need to wait for compilation of a build script.

Caches the result of running rustc so that multiple build scripts will use the same result.

Support Rust 1.31

• Deprecate date! macro, because it can't be implemented on Rust 1.31
• Run tests on MSRV (previously only ran cargo check)
• Use cargo rdme to sync README.md with crate docs.
• Use github actions to run lychee link-checker on README.md

This reduces the MSRV from 1.32 to 1.31.

Deprecate `spec!` macro in favor of helper methods

Use the RustVersion.is_since_major_version and RustVersion.is_since_patch_version methods instead of is_since(spec!(...)).

This avoids a macro import, is simpler, faster, and allows const evaulation.

The macro will be removed in a future version.

Fix compilation on MSRV

• Bump MSRV from 1.31 to 1.32 because of needed macro features
• Add basic compile-time benchmarks (only one laptop)
• Fix broken documentation link to StableVersionSpec::minor
• Fix reference to rustversion crate in README.md

Initial release as rustversion-detect

Code based off rustversion, but with all procedural macro code removed.