Changeset 34378 in vbox

Timestamp:

Nov 25, 2010 3:48:43 PM (14 years ago)

Author:

vboxsync

Message:

iprt/cdefs.h: Added RT_IS_POWER_OF_TWO.

File:

• trunk/include/iprt/cdefs.h (modified) (1 diff)

trunk/include/iprt/cdefs.h

@@ -1173 +1173 @@
  */
 #define RT_ELEMENTS(aArray)                     ( sizeof(aArray) / sizeof((aArray)[0]) )
+
+/**
+ * Checks if the value is a power of two.
+ *
+ * @returns true if power of two, false if not.
+ * @param   uVal                The value to test.
+ * @remarks 0 is a power of two.
+ * @see     VERR_NOT_POWER_OF_TWO
+ */
+#define RT_IS_POWER_OF_TWO(uVal)                ( ((uVal) & ((uVal) - 1)) == 0)
 
 #ifdef RT_OS_OS2