+#define twimap_index(twimap, type) ((type)((twimap)->index))
+#define twimap_data(twimap, type) ((type)((twimap)->data))
+
+struct twimap*
+twifs_mapping(struct twifs_node* parent, void* data, const char* fmt, ...);
+
+void
+twimap_printf(struct twimap* mapping, const char* fmt, ...);
+
+int
+twimap_memcpy(struct twimap* mapping, const void* src, const size_t len);
+
+int
+twimap_memappend(struct twimap* mapping, const void* src, const size_t len);
+