+class trace_class_environment_visitor {
+public:
+ trace_class_environment_visitor() = default;
+ virtual ~trace_class_environment_visitor() = default;
+ trace_class_environment_visitor(const trace_class_environment_visitor&) = delete;
+ trace_class_environment_visitor(trace_class_environment_visitor&&) = delete;
+ trace_class_environment_visitor& operator=(trace_class_environment_visitor&&) = delete;
+ trace_class_environment_visitor& operator=(const trace_class_environment_visitor&) = delete;
+
+ virtual void visit(const environment_field<int64_t>& field) = 0;
+ virtual void visit(const environment_field<const char *>& field) = 0;
+ virtual void visit(const environment_field<std::string>& field);
+};
+