Ticket #10830: param_not_found_static_instance.patch

named_function_params.hpp

@@ -227 +227 @@
     }
   };
 
-  struct param_not_found {};
+  struct param_not_found {
+    static param_not_found& instance()
+    {
+      static param_not_found instance_;
+      return instance_;
+    }
+  };
 
   template <typename Tag, typename Args>
   struct get_param_type: 
@@ -237 +243 @@
   inline
   const typename lookup_named_param_def<Tag, Args, param_not_found>::type&
   get_param(const Args& p, Tag) {
-    return lookup_named_param_def<Tag, Args, param_not_found>::get(p, param_not_found());
+    return lookup_named_param_def<Tag, Args, param_not_found>::get(p, param_not_found::instance());
   }
 
   template <class P, class Default>