flow: Make assertions about offsets within struct flow easier to follow.

[cascardo/ovs.git] / lib / util.h

diff --git a/lib/util.h b/lib/util.h
index 59276e3..0d1e727 100644 (file)
--- a/lib/util.h
+++ b/lib/util.h
@@ -199,6 +199,9 @@ ovs_prefetch_range(const void *start, size_t size)
     ((char *) &(OBJECT)->MEMBER - (char *) (OBJECT))
 #endif
 
+/* Yields the size of MEMBER within STRUCT. */
+#define MEMBER_SIZEOF(STRUCT, MEMBER) (sizeof(((STRUCT *) NULL)->MEMBER))
+
 /* Given POINTER, the address of the given MEMBER in a STRUCT object, returns
    the STRUCT object. */
 #define CONTAINER_OF(POINTER, STRUCT, MEMBER)                           \