+ implementation

include/refcnt/Displayable.hpp

@@ -0,0 +1,29 @@
+/* @file Displayable.hpp */
+
+#pragma once
+
+#include "refcnt/Refcounted.hpp"
+
+namespace xo {
+    namespace ref {
+        class Displayable : public Refcount {
+        public:
+            /* write some kind of human-readable representation on stream */
+            virtual void display(std::ostream & os) const = 0;
+            std::string display_string() const;
+        }; /*Displayable*/
+
+        /* see also
+         *   operator<<(std::ostream &, intrusive_ptr<T> const &)
+         * in [Refcounted.hpp]
+         */
+        inline std::ostream &
+        operator<<(std::ostream &os, Displayable const & x) {
+            x.display(os);
+            return os;
+        } /*operator<<*/
+
+    } /*namespace ref*/
+} /*namespace xo*/
+
+/* end Displayable.hpp */