Add a few more links to objc2::rc documentation

Author: madsmtm

objc2/src/rc/autorelease.rs

@@ -13,13 +13,6 @@ use crate::runtime::{objc_autoreleasePoolPop, objc_autoreleasePoolPush};
 ///
 /// And this is not [`Sync`], since you can only autorelease a reference to a
 /// pool on the current thread.
-///
-/// See [the clang documentation][clang-arc] and [the apple article on memory
-/// management][memory-mgmt] for more information on automatic reference
-/// counting.
-///
-/// [clang-arc]: https://clang.llvm.org/docs/AutomaticReferenceCounting.html
-/// [memory-mgmt]: https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/MemoryMgmt/Articles/MemoryMgmt.html
 pub struct AutoreleasePool {
     context: *mut c_void,
 }

objc2/src/rc/mod.rs

@@ -10,8 +10,18 @@ and safely fails if the object has been deallocated.
 These utilities are not intended to provide a fully safe interface, but can be
 useful when writing higher-level Rust wrappers for Objective-C code.
 
-For more information on Objective-C's reference counting, see Apple's documentation:
-<https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/MemoryMgmt/Articles/MemoryMgmt.html>
+See [the clang documentation][clang-arc] and [the Apple article on memory
+management][mem-mgmt] (similar document exists [for Core Foundation][mem-cf])
+for more information on automatic and manual reference counting.
+
+It can also be useful to [enable Malloc Debugging][mem-debug] if you're trying
+to figure out if/where your application has memory errors and leaks.
+
+
+[clang-arc]: https://clang.llvm.org/docs/AutomaticReferenceCounting.html
+[mem-mgmt]: https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/MemoryMgmt/Articles/MemoryMgmt.html
+[mem-cf]: https://developer.apple.com/library/archive/documentation/CoreFoundation/Conceptual/CFMemoryMgmt/CFMemoryMgmt.html
+[mem-debug]: https://developer.apple.com/library/archive/documentation/Performance/Conceptual/ManagingMemory/Articles/MallocDebug.html
 
 # Example
 

objc2_id/src/id.rs

@@ -99,6 +99,7 @@ impl Ownership for Shared {}
 /// ```
 #[repr(transparent)]
 // TODO: Figure out if `Message` bound on `T` would be better here?
+// TODO: Add `?Sized + ptr::Thin` bound on `T` to allow for extern types
 pub struct Id<T, O: Ownership = Owned> {
     /// A pointer to the contained object. The pointer is always retained.
     ///