#include <set>
#include <stdexcept>
#include <sigc++/trackable.h>
+#include <msp/datafile/statement.h>
#include "trackiter.h"
namespace R2C2 {
private:
void object_removed(Object &);
+
+public:
+ virtual Msp::DataFile::Statement save_reference() const = 0;
};
} // namespace R2C2