svn commit: r236486 - head/sys/sys

[Marius Strobl]

Author: marius
Date: Sat Jun  2 19:30:49 2012
New Revision: 236486
URL: http://svn.freebsd.org/changeset/base/236486

Log:
  Add nitems(), a macro for determining the number of elements in a
  statically-allocated array.
  
  Obtained from:	OpenBSD (in principle)
  MFC after:	3 days

Modified:
  head/sys/sys/param.h

Modified: head/sys/sys/param.h
==============================================================================
--- head/sys/sys/param.h	Sat Jun  2 19:21:34 2012	(r236485)
+++ head/sys/sys/param.h	Sat Jun  2 19:30:49 2012	(r236486)
@@ -273,6 +273,7 @@
 #ifndef howmany
 #define	howmany(x, y)	(((x)+((y)-1))/(y))
 #endif
+#define	nitems(x)	(sizeof((x)) / sizeof((x)[0]))
 #define	rounddown(x, y)	(((x)/(y))*(y))
 #define	roundup(x, y)	((((x)+((y)-1))/(y))*(y))  /* to any y */
 #define	roundup2(x, y)	(((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */