Address review comments.

aprilnovak · aprilnovak · commit fa222a4b314d · 2023-03-27T19:23:04.000-05:00
diff --git a/include/openmc/material.h b/include/openmc/material.h
@@ -91,7 +91,7 @@ class Material {
     const vector<std::string>& name, const vector<double>& density);
 
   //! Clone the material by deep-copying all members
-  void clone();
+  Material & clone();
 
   //----------------------------------------------------------------------------
   // Accessors
