-Copyright (C) 1999-2007 id Software, Inc. and contributors.
-For a list of contributors, see the accompanying CONTRIBUTORS file.
-
-This file is part of GtkRadiant.
-
-GtkRadiant is free software; you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2 of the License, or
-(at your option) any later version.
-
-GtkRadiant is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with GtkRadiant; if not, write to the Free Software
-Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
-*/
-
-#ifndef _IUNDO_H_
-#define _IUNDO_H_
-
-#define UNDO_MAJOR "undo"
-
-//start operation
-typedef void (*PFN_UNDOSTART) (char *operation);
-//end operation
-typedef void (*PFN_UNDOEND) (void);
-//add brush to the undo
-typedef void (*PFN_UNDOADDBRUSH) (brush_t *pBrush);
-//end a brush after the operation is performed
-typedef void (*PFN_UNDOENDBRUSH) (brush_t *pBrush);
-//add a list with brushes to the undo
-typedef void (*PFN_UNDOADDBRUSHLIST) (brush_t *brushlist);
-//end a list with brushes after the operation is performed
-typedef void (*PFN_UNDOENDBRUSHLIST) (brush_t *brushlist);
-//add entity to undo
-typedef void (*PFN_UNDOADDENTITY) (entity_t *entity);
-//end an entity after the operation is performed
-typedef void (*PFN_UNDOENDENTITY) (entity_t *entity);
-//undo last operation (bSilent == true -> will not print the "undone blah blah message")
-typedef void (*PFN_UNDO) (unsigned char bSilent);
-//redo last undone operation
-typedef void (*PFN_REDO) (void);
-//get the undo Id of the next undo (0 if none available)
-typedef int (*PFN_GETUNDOID) (void);
-//returns true if there is something to be undone available
-typedef int (*PFN_UNDOAVAILABLE) (void);
-//returns true if there is something to redo available
-typedef int (*PFN_REDOAVAILABLE) (void);
-
-struct _QERUndoTable
+ Copyright (C) 2001-2006, William Joseph.
+ All Rights Reserved.
+
+ This file is part of GtkRadiant.
+
+ GtkRadiant is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ GtkRadiant is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with GtkRadiant; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#if !defined( INCLUDED_IUNDO_H )
+#define INCLUDED_IUNDO_H
+
+/// \file
+/// \brief The undo-system interface. Uses the 'memento' pattern.
+
+#include <cstddef>
+#include "generic/constant.h"
+#include "generic/callbackfwd.h"
+
+class UndoMemento