Update template lib.rs to newer format

prebuilt-template/src/lib.rs

@@ -1,47 +1,58 @@
 /*
+ * Copyright (c) godot-rust; Bromeon and contributors.
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at https://mozilla.org/MPL/2.0/.
  */
 
-// Note: this API is not necessarily forward-compatible. It can be updated on demand (for all published Godot versions).
-// Important is that the latest version of gdext can be used together with all latest published artifacts.
-// For long-term stability, it may be helpful to have a dynamic query mechanism, such as:
-//   fn get_property(key: &str) -> Option<String>
+// Since this lib.rs is repurposed as a module file, avoid crate-level attributes such as
+// #![doc(html_logo_url)] here.
 
-/// Version of the Godot engine that the API JSON and C header mirror.
-/// Note that this currently only contains the `major.minor[.patch]` part, so even `4.2-rc1` will be `4.2`.
-pub const GODOT_VERSION: &str = "%GODOT4_VER%";
+//! # GDExtension API for Godot %GODOT4_VER%
+
+use std::borrow::Cow;
 
-/// Version of the Rust compiler used to build this artifact.
-/// Is still a number even for nightly versions.
-pub const RUST_VERSION: &str = "%RUST_VER%";
+/// Abstracts from borrow/owned and allows to change implementation without affecting API.
+pub type CowStr = Cow<'static, str>;
 
-/// Version of the `bindgen` crate used to generate the `gdextension_interface.h` Rust binding.
-pub const BINDGEN_VERSION: &str = "%BINDGEN_VER%";
+/// Version of the Godot engine that the API JSON and C header mirror.
+///
+/// Note that this currently only contains the `major.minor[.patch]` part, so even `4.2-rc1` would be `4.2` (although pre-releases are currently
+/// not published).
+pub const GODOT_VERSION_STRING: &str = "%GODOT4_VER%";
 
 /// Returns the contents of the header file `gdextension_interface.h`.
-pub const fn load_gdextension_header_h() -> &'static str {
-    include_str!("../res/gdextension_interface.h")
+pub const fn load_gdextension_header_h() -> CowStr {
+    CowStr::Borrowed(include_str!("../res/gdextension_interface.h"))
 }
 
 /// Returns the contents of the header file `gdextension_interface.rs`, generated for the corresponding platform.
-pub const fn load_gdextension_header_rs() -> &'static str {
+pub const fn load_gdextension_header_rs() -> CowStr {
     #[cfg(windows)]
-    {
-        include_str!("../res/gdextension_interface_windows.rs")
-    }
+    let s = include_str!("../res/gdextension_interface_windows.rs");
+
     #[cfg(target_os = "macos")]
-    {
-        include_str!("../res/gdextension_interface_macos.rs")
-    }
+    let s = include_str!("../res/gdextension_interface_macos.rs");
+
     #[cfg(all(unix, not(target_os = "macos")))]
-    {
-        include_str!("../res/gdextension_interface_linux.rs")
-    }
+    let s = include_str!("../res/gdextension_interface_linux.rs");
+
+    CowStr::Borrowed(s)
 }
 
 /// Returns the contents of the JSON API file `extension_api.json`.
-pub const fn load_gdextension_json() -> &'static str {
-    include_str!("../res/extension_api.json")
+pub const fn load_gdextension_json() -> CowStr {
+    Cow::Borrowed(include_str!("../res/extension_api.json"))
+}
+
+/// Dynamically fetch a property of this crate.
+pub fn get_package_property(key: &str) -> Option<CowStr> {
+    let value = match key {
+        "godot_version_string" => Cow::Borrowed(GODOT_VERSION_STRING),
+        "rust_version_string" => Cow::Borrowed("%RUST_VER%"),
+        "bindgen_version_string" => Cow::Borrowed("%BINDGEN_VER%"),
+        _ => return None,
+    };
+
+    Some(value)
 }