1 files changed, 20 insertions, 1 deletions
diff --git a/util/macros.h b/util/macros.h
index 0104d9f..54faee5 100644
--- a/util/macros.h
+++ b/util/macros.h
@@ -1,8 +1,18 @@
 /*
  * Some standard helpful macros.
  *
+ * The canonical version of this file is maintained in the rra-c-util package,
+ * which can be found at <http://www.eyrie.org/~eagle/software/rra-c-util/>.
+ *
  * Written by Russ Allbery <rra@stanford.edu>
- * This work is hereby placed in the public domain by its author.
+ *
+ * The authors hereby relinquish any claim to any copyright that they may have
+ * in this work, whether granted under contract or by operation of law or
+ * international treaty, and hereby commit to the public, at large, that they
+ * shall not, at any time in the future, seek to enforce any copyright in this
+ * work against any person or entity, or prevent any person or entity from
+ * copying, publishing, distributing or creating derivative works of this
+ * work.
  */
 
 #ifndef UTIL_MACROS_H
@@ -10,6 +20,15 @@
 
 #include <portable/macros.h>
 
+/*
+ * Used for iterating through arrays.  ARRAY_SIZE returns the number of
+ * elements in the array (useful for a < upper bound in a for loop) and
+ * ARRAY_END returns a pointer to the element past the end (ISO C99 makes it
+ * legal to refer to such a pointer as long as it's never dereferenced).
+ */
+#define ARRAY_SIZE(array) (sizeof(array) / sizeof((array)[0]))
+#define ARRAY_END(array)  (&(array)[ARRAY_SIZE(array)])
+
 /* Used for unused parameters to silence gcc warnings. */
 #define UNUSED __attribute__((__unused__))