--- source/common/unicode/uobject.h
+++ source/common/unicode/uobject.h
@@ -245,10 +245,10 @@
     // direct use of UObject itself
 
     // default constructor
-    // inline UObject() {}
+    UObject() = default;
 
     // copy constructor
-    // inline UObject(const UObject &other) {}
+    UObject(const UObject &other) = default;
 
 #if 0
     // TODO Sometime in the future. Implement operator==().
@@ -280,8 +280,8 @@
      * Subclasses need this assignment operator if they use compiler-provided
      * assignment operators of their own. An alternative to not declaring one
      * here would be to declare and empty-implement a protected or public one.
-    UObject &UObject::operator=(const UObject &);
      */
+    UObject &operator=(const UObject &) = default;
 };
 
 #ifndef U_HIDE_INTERNAL_API