Merge pull request #59362 from apple/AnthonyLatsis-patch-1

Author: AnthonyLatsis

CHANGELOG.md

@@ -90,22 +90,33 @@ _**Note:** This is in reverse chronological order, so newer entries are added to
   }
   ```
 
-* References to `optional` methods on a protocol metatype, as well as references to dynamically looked up methods on the `AnyObject` metatype are now supported. These references always have the type of a function that accepts a single argument and returns an optional value of function type:
+* References to `optional` methods on a protocol metatype, as well as references to dynamically looked up methods on `AnyObject` are now supported on par with other function references. The type of such a reference (formerly an immediate optional by mistake) has been altered to that of a function that takes a single argument and returns an optional value of function type:
 
   ```swift
   class Object {
-    @objc func getTag() -> Int
+    @objc func getTag() -> Int { ... }
   }
 
-  @objc protocol P {
+  let getTag: (AnyObject) -> (() -> Int)? = AnyObject.getTag
+
+  @objc protocol Delegate {
     @objc optional func didUpdateObject(withTag tag: Int)
   }
 
-  let getTag: (AnyObject) -> (() -> Int)? = AnyObject.getTag
-
-  let didUpdateObject: (any P) -> ((Int) -> Void)? = P.didUpdateObject
+  let didUpdateObjectWithTag: (Delegate) -> ((Int) -> Void)? = Delegate.didUpdateObject
   ```
 
+  > **Warning**  
+  > Due to the type change, selectors for aforementioned method references that require writing out their type explicitly for disambiguation will no longer compile. To fix this, simply adjust the written type, or resort to a `#if swift(<5.7)` directive when compatibility with older compiler versions is warranted. For example:
+  >
+  > ```swift
+  > #if swift(<5.7)
+  > let decidePolicyForNavigationAction = #selector(WKNavigationDelegate.webView(_:decidePolicyFor:decisionHandler:) as ((WKNavigationDelegate) -> (WKWebView, WKNavigationAction, @escaping (WKNavigationActionPolicy) -> Void) -> Void)?)
+  > #else
+  > let decidePolicyForNavigationAction = #selector(WKNavigationDelegate.webView(_:decidePolicyFor:decisionHandler:) as (WKNavigationDelegate) -> ((WKWebView, WKNavigationAction, @escaping (WKNavigationActionPolicy) -> Void) -> Void)?)
+  > #endif
+  > ```
+
 * [SE-0349][]:
 
   Loading data from raw memory represented by `UnsafeRawPointer`,