add extra document comment

Signed-off-by: Chen Lihui <[email protected]>

include/class_loader/class_loader_core.hpp

@@ -89,8 +89,10 @@ class MetaObjectGraveyardVector : public MetaObjectVector
   {
     // Make sure not to access the pointer value in the static variable of `getMetaObjectGraveyard()
     // when destroying `meta_object` in the unique_ptr deleter. Because the static variable in
-    // `getMetaObjectGraveyard()` could be finalized before the static variable
+    // `getMetaObjectGraveyard()` can be destructed before the static variable
     // `g_register_plugin_ ## UniqueID` in some circumstances.
+    // NOTE of the vector dtor in the STL: if the elements themselves are pointers, the pointed-to
+    // memory is not touched in any way.  Managing the pointer is the user's responsibility.
     clear();
   }
 };