Make AnyObject.class return a static

Author: madsmtm

crates/objc2/CHANGELOG.md

@@ -50,6 +50,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
   `MethodImplementation` to `Return` and `Arguments`.
 * **BREAKING**: Make `rc::Allocated` allowed to be `NULL` internally, such
   that uses of `Option<Allocated<T>>` is now simply `Allocated<T>`.
+* `AnyObject::class` now returns a `'static` reference to the class.
 
 ### Deprecated
 * Soft deprecated using `msg_send!` without a comma between arguments (i.e.

crates/objc2/src/runtime/mod.rs

@@ -1052,9 +1052,11 @@ impl AnyObject {
 
     /// Dynamically find the class of this object.
     #[doc(alias = "object_getClass")]
-    pub fn class(&self) -> &AnyClass {
+    pub fn class(&self) -> &'static AnyClass {
         let ptr: *const AnyClass = unsafe { ffi::object_getClass(self.as_ptr()) }.cast();
-        // SAFETY: The class is not NULL because the object is not NULL.
+        // SAFETY: The class is not NULL because the object is not NULL, and
+        // it is safe as `'static` since classes are static, and it could be
+        // retrieved via. `AnyClass::get(self.class().name())` anyhow.
         unsafe { ptr.as_ref().unwrap_unchecked() }
     }