Make zarrs::version::version_{major,minor,patch} const

CHANGELOG.md

@@ -7,6 +7,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+- Make `zarrs::version::version_{major,minor,patch}` const
+
 ## [0.18.0-beta.0] - 2024-11-15
 
 ### Highlights

zarrs/build.rs

@@ -0,0 +1,24 @@
+#![allow(missing_docs)]
+
+use std::env;
+use std::fs;
+use std::io::Write;
+use std::path::Path;
+
+fn main() {
+    let major_version = env::var("CARGO_PKG_VERSION_MAJOR").unwrap();
+    let minor_version = env::var("CARGO_PKG_VERSION_MINOR").unwrap();
+    let patch_version = env::var("CARGO_PKG_VERSION_PATCH").unwrap();
+    let out_dir = env::var("OUT_DIR").unwrap();
+    let dest_path = Path::new(&out_dir).join("version.rs");
+
+    let mut file = fs::File::create(dest_path).unwrap();
+    file.write_fmt(format_args!(
+        r"
+pub(crate) const VERSION_MAJOR: u32 = {major_version};
+pub(crate) const VERSION_MINOR: u32 = {minor_version};
+pub(crate) const VERSION_PATCH: u32 = {patch_version};
+"
+    ))
+    .unwrap();
+}

zarrs/src/version.rs

@@ -1,27 +1,23 @@
 //! `zarrs` version information.
 
+include!(concat!(env!("OUT_DIR"), "/version.rs"));
+
 /// The `zarrs` major version.
 #[must_use]
-pub fn version_major() -> u32 {
-    const VERSION_MAJOR: &str = env!("CARGO_PKG_VERSION_MAJOR");
-    let major: u32 = VERSION_MAJOR.parse::<u32>().unwrap_or_default();
-    major
+pub const fn version_major() -> u32 {
+    VERSION_MAJOR
 }
 
 /// The `zarrs` minor version.
 #[must_use]
-pub fn version_minor() -> u32 {
-    const VERSION_MINOR: &str = env!("CARGO_PKG_VERSION_MINOR");
-    let minor: u32 = VERSION_MINOR.parse::<u32>().unwrap_or_default();
-    minor
+pub const fn version_minor() -> u32 {
+    VERSION_MINOR
 }
 
 /// The `zarrs` patch version.
 #[must_use]
-pub fn version_patch() -> u32 {
-    const VERSION_PATCH: &str = env!("CARGO_PKG_VERSION_PATCH");
-    let patch: u32 = VERSION_PATCH.parse::<u32>().unwrap_or_default();
-    patch
+pub const fn version_patch() -> u32 {
+    VERSION_PATCH
 }
 
 /// A [`u32`] representation of the `zarrs` version.