fix issue#15, minor wrapper_class issue. (#16)

src/wrapper_class.cpp

@@ -74,7 +74,7 @@ class IntPtrManager {
       other.ptr_ = nullptr;
     }
 
-    // Move assignment operator for class Person. Similar techniques as
+    // Move assignment operator for this wrapper class. Similar techniques as
     // the move constructor.
     IntPtrManager &operator=(IntPtrManager &&other) {
       ptr_ = other.ptr_;
@@ -130,4 +130,4 @@ int main() {
   // it is managing.
 
   return 0;
-}
+}