/* PSPP - a program for statistical analysis.
- Copyright (C) 2007 Free Software Foundation, Inc.
+ Copyright (C) 2007, 2009, 2011 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
#ifndef LIBPSPP_HEAP_H
#define LIBPSPP_HEAP_H 1
+#include "libpspp/cast.h"
#include <stdbool.h>
#include <stddef.h>
/* Returns the data structure corresponding to the given heap
NODE, assuming that NODE is embedded as the given MEMBER name
in data type STRUCT. */
-#define heap_data(NODE, STRUCT, MEMBER) \
- ((STRUCT *) ((char *) (NODE) - offsetof (STRUCT, MEMBER)))
+#define heap_data(NODE, STRUCT, MEMBER) \
+ (CHECK_POINTER_HAS_TYPE (NODE, struct heap_node *), \
+ UP_CAST (NODE, STRUCT, MEMBER))
/* A node in a heap. Opaque.
One of these structures must be embedded in your heap node. */