X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Flibpspp%2Fhmap.h;h=1592f803bedb17bd9c1ca4dc285f5bd6e72fd1c4;hb=84bbf9c2cabe154765e406114b5386bf309aed27;hp=e73d84fd153764ec96935c6242dc2388820c5757;hpb=9a331fe64eb814ae5c1322e21717a04fb254bf65;p=pspp-builds.git

diff --git a/src/libpspp/hmap.h b/src/libpspp/hmap.h
index e73d84fd..1592f803 100644
--- a/src/libpspp/hmap.h
+++ b/src/libpspp/hmap.h
@@ -1,5 +1,5 @@
 /* PSPP - a program for statistical analysis.
-   Copyright (C) 2008 Free Software Foundation, Inc.
+   Copyright (C) 2008, 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
@@ -115,13 +115,16 @@
        }
    */
 
+#include <stdbool.h>
 #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.  NODE must not be a null pointer. */
 #define HMAP_DATA(NODE, STRUCT, MEMBER)                         \
-  ((STRUCT *) ((char *) (NODE) - offsetof (STRUCT, MEMBER)))
+        (CHECK_POINTER_HAS_TYPE (NODE, struct hmap_node *),     \
+         UP_CAST (NODE, STRUCT, MEMBER))
 
 /* Like HMAP_DATA, except that a null NODE yields a null pointer
    result. */
@@ -180,6 +183,7 @@ static inline struct hmap_node *hmap_next (const struct hmap *,
                                            const struct hmap_node *);
 
 /* Counting. */
+static bool hmap_is_empty (const struct hmap *);
 static inline size_t hmap_count (const struct hmap *);
 static inline size_t hmap_capacity (const struct hmap *);
 
@@ -440,6 +444,14 @@ hmap_next (const struct hmap *map, const struct hmap_node *node)
           : hmap_first_nonempty_bucket__ (map, (node->hash & map->mask) + 1));
 }
 
+/* Returns true if MAP currently contains no data items, false
+   otherwise. */
+static inline bool
+hmap_is_empty (const struct hmap *map)
+{
+  return map->count == 0;
+}
+
 /* Returns the number of data items currently in MAP. */
 static inline size_t
 hmap_count (const struct hmap *map)