+#ifndef offsetof
+#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *) 0)->MEMBER)
+#endif
+#ifndef container_of
+#define container_of(ptr, type, member) ({ \
+ const typeof(((type *) 0)->member) *__mptr = (ptr); \
+ (type *) ((char *) __mptr - offsetof(type, member));})
+#endif
+
+#define typeof_field(type, field) typeof(((type *)0)->field)
+#define type_check(t1,t2) ((t1*)0 - (t2*)0)
+