--- /dev/null
+////////////////////////////////////////////////////////////////////////////////\r
+\r
+// Author: Andy Rushton\r
+// Copyright: (c) Southampton University 1999-2004\r
+// (c) Andy Rushton 2004-2009\r
+// License: BSD License, see ../docs/license.html\r
+\r
+// format: magic_key [ data ]\r
+\r
+////////////////////////////////////////////////////////////////////////////////\r
+#include "persistent_int.hpp"\r
+\r
+namespace stlplus\r
+{\r
+\r
+ ////////////////////////////////////////////////////////////////////////////////\r
+\r
+ template<typename T>\r
+ void dump_xref(dump_context& context, const T* const data)\r
+ throw(persistent_dump_failed)\r
+ {\r
+ // register the address and get the magic key for it\r
+ std::pair<bool,unsigned> mapping = context.pointer_map(data);\r
+ // if this is the first view of this pointer, simply throw an exception\r
+ if (!mapping.first) throw persistent_dump_failed("tried to dump a cross-reference not seen before");\r
+ // otherwise, just dump the magic key\r
+ dump_unsigned(context,mapping.second);\r
+ }\r
+\r
+ ////////////////////////////////////////////////////////////////////////////////>\r
+\r
+ template<typename T>\r
+ void restore_xref(restore_context& context, T*& data)\r
+ throw(persistent_restore_failed)\r
+ {\r
+ // Note: I do not try to delete the old data because this is a cross-reference\r
+ // get the magic key\r
+ unsigned magic = 0;\r
+ restore_unsigned(context,magic);\r
+ // now lookup the magic key to see if this pointer has already been restored\r
+ // null pointers are always flagged as already restored\r
+ std::pair<bool,void*> address = context.pointer_map(magic);\r
+ // if this is the first view of this pointer, simply throw an exception\r
+ if (!address.first) throw persistent_restore_failed("tried to restore a cross-reference not seen before");\r
+ // seen before, so simply assign the old address\r
+ data = (T*)address.second;\r
+ }\r
+\r
+ ////////////////////////////////////////////////////////////////////////////////\r
+\r
+} // end namespace stlplus\r