+ // functions overriding virtual functions from base classes
+public:
+ /** Save (a.k.a. serialize) object into archive. */
+ void archive(archive_node& n) const override;
+ /** Read (a.k.a. deserialize) object from archive. */
+ void read_archive(const archive_node& n, lst& syms) override;
+protected:
+ unsigned calchash() const override;
+