1 files changed, 105 insertions, 0 deletions

diff --git a/include/konforka/pointer_map.h b/include/konforka/pointer_map.h
new file mode 100644
index 0000000..d706e71
--- a/dev/null
+++ b/include/konforka/pointer_map.h
@@ -0,0 +1,105 @@
+#ifndef __KONFORKA_POINTER_MAP_H
+#define __KONFORKA_POINTER_MAP_H
+
+#include <typeinfo>
+
+/**
+ * @file
+ * @brief mapping of pointers.
+ *
+ * The support for global mapping of pointers. Useful when using third-party
+ * libraries callbacks when the library does not provide mechanism for passing
+ * along custom context-dependent data.
+ */
+
+namespace konforka {
+
+    /**
+     * @brief internally used actual implementation of mapping pointer.
+     *
+     * @param tf the typeid of the key pointer.
+     * @param pf the key pointer.
+     * @param tt the typeid of the value pointer.
+     * @param pt the value pointer.
+     */
+    void _map_pointer(const type_info& tf,void *pf,const type_info& tt,void *pt);
+    /**
+     * @brief internally used actual implementation of destroying mapped
+     * pointer.
+     *
+     * @param tf the typeid of the key pointer.
+     * @param pf the key pointer.
+     * @param tt the typeid of the value pointer.
+     * @param pt the value pointer.
+     */
+    void _unmap_pointer(const type_info& tf,void *pf,const type_info& tt,void *pt);
+    /**
+     * @brief internally used actual implementation of retrieving mapped
+     * pointer.
+     *
+     * @param tf the typeid of the key pointer.
+     * @param pf the key pointer.
+     * @param tt the typeid of the value pointer.
+     * @return the value.
+     */
+    void *_mapped_pointer(const type_info& tf,void *pf,const type_info& tt);
+
+    /**
+     * @brief the object, maintaining mapped pointer.
+     * 
+     * @param from_t the key type.
+     * @param to_t the value type.
+     */
+    template<typename from_t,typename to_t>
+        class map_pointer {
+            public:
+                /**
+                 * stored key.
+                 */
+                from_t _from;
+                /**
+                 * stored value.
+                 */
+                to_t _to;
+                /**
+                 * flag, specifying that the object is currently mapped.
+                 */
+                bool bmapped;
+
+                /**
+                 * @brief constructs the object, mapping the key/value pair.
+                 * 
+                 * @param f the key.
+                 * @param t the value.
+                 */
+                map_pointer(from_t f,to_t t)
+                    : _from(f), _to(t), bmapped(false) {
+                        _map_pointer(typeid(from_t),_from,typeid(to_t),_to);
+                        bmapped=true;
+                    }
+                /**
+                 * @brief destructor unmaps the key/value pair stored.
+                 */
+                ~map_pointer() {
+                    if(bmapped)
+                        _unmap_pointer(typeid(from_t),_from,typeid(to_t),_to);
+                }
+        };
+
+    /**
+     * The template function for pointer retrieval.
+     *
+     * @param from_t the key type.
+     * @param to_t the value type.
+     * @param f the key.
+     * @return the value.
+     */
+    template<typename from_t,typename to_t>
+        to_t mapped_pointer(from_t f) {
+            return (to_t)_mapped_pointer(typeid(from_t),f,typeid(to_t));
+        }
+
+}
+
+#endif /* __KONFORKA_POINTER_MAP_H */
+/* vim:set ft=cpp: */