remove filter function from protocol and add it to the extenstion

Author: mkandil

stdlib/public/Cxx/CxxDictionary.swift

@@ -25,7 +25,20 @@ public protocol CxxDictionary<Key, Value> {
 
   /// Do not implement this function manually in Swift.
   func __endUnsafe() -> RawIterator
+}
 
+extension CxxDictionary {
+  @inlinable
+  public subscript(key: Key) -> Value? {
+    get {
+      let iter = __findUnsafe(key)
+      guard iter != __endUnsafe() else {
+        return nil
+      }
+      return iter.pointee.second
+    }
+  }
+  
   func filter(
     _ isIncluded: (Key, Value) throws -> Bool
   ) rethrows -> [Key: Value] {
@@ -42,16 +55,3 @@ public protocol CxxDictionary<Key, Value> {
     }
   }
 }
-
-extension CxxDictionary {
-  @inlinable
-  public subscript(key: Key) -> Value? {
-    get {
-      let iter = __findUnsafe(key)
-      guard iter != __endUnsafe() else {
-        return nil
-      }
-      return iter.pointee.second
-    }
-  }
-}