Changeset 73101 in vbox for trunk/include/iprt

Timestamp:

Jul 12, 2018 9:23:36 PM (7 years ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

123678

Message:

Added RT_FROM_MEMBER_DYN for use in cases like pic_poll_read.

File:

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

trunk/include/iprt/cdefs.h

@@ -2386 +2386 @@
 #endif
 
+/** @def RT_FROM_MEMBER_DYN
+ * Convert a pointer to a structure member into a pointer to the structure.
+ *
+ * @returns pointer to the structure.
+ * @param   pMem    Pointer to the member.
+ * @param   Type    Structure type.
+ * @param   Member  Member name dynamic size (some array is index by
+ *                  non-constant value).
+ */
+#define RT_FROM_MEMBER_DYN(pMem, Type, Member)  ( (Type *) ((uint8_t *)(void *)(pMem) - RT_UOFFSETOF_DYN(Type, Member)) )
+
 /** @def RT_ELEMENTS
  * Calculates the number of elements in a statically sized array.