/* PSPP - a program for statistical analysis.
- Copyright (C) 2007 Free Software Foundation, Inc.
+ Copyright (C) 2007, 2009 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
tree paper. */
#include <stddef.h>
+#include <libpspp/cast.h>
/* Returns the data structure corresponding to the given NODE,
assuming that NODE is embedded as the given MEMBER name in
data type STRUCT. */
-#define abt_data(NODE, STRUCT, MEMBER) \
- ((STRUCT *) ((char *) (NODE) - offsetof (STRUCT, MEMBER)))
+#define abt_data(NODE, STRUCT, MEMBER) \
+ (CHECK_POINTER_HAS_TYPE (NODE, struct abt_node *), \
+ UP_CAST (NODE, STRUCT, MEMBER))
/* Node in an augmented binary tree. */
struct abt_node