return (const char *)h->n.next - off;
}
+/**
+ * list_pop - remove the first entry in a list
+ * @h: the list_head
+ * @type: the type of the entry
+ * @member: the list_node member of the type
+ *
+ * If the list is empty, returns NULL.
+ *
+ * Example:
+ * struct child *one;
+ * one = list_pop(&parent->children, struct child, list);
+ * if (!one)
+ * printf("Empty list!\n");
+ */
+#define list_pop(h, type, member) \
+ ((type *)list_pop_((h), list_off_(type, member)))
+
+static inline const void *list_pop_(const struct list_head *h, size_t off)
+{
+ struct list_node *n;
+
+ if (list_empty(h))
+ return NULL;
+ n = h->n.next;
+ list_del(n);
+ return (const char *)n - off;
+}
+
/**
* list_tail - get the last entry in a list
* @h: the list_head
#define list_for_each_safe(h, i, nxt, member) \
list_for_each_safe_off(h, i, nxt, list_off_var_(i, member))
+/**
+ * list_next - get the next entry in a list
+ * @h: the list_head
+ * @i: a pointer to an entry in the list.
+ * @member: the list_node member of the structure
+ *
+ * If @i was the last entry in the list, returns NULL.
+ *
+ * Example:
+ * struct child *second;
+ * second = list_next(&parent->children, first, list);
+ * if (!second)
+ * printf("No second child!\n");
+ */
+#define list_next(h, i, member) \
+ ((list_typeof(i))list_entry_or_null(list_debug(h), \
+ (i)->member.next, \
+ list_off_var_((i), member)))
+
+/**
+ * list_prev - get the previous entry in a list
+ * @h: the list_head
+ * @i: a pointer to an entry in the list.
+ * @member: the list_node member of the structure
+ *
+ * If @i was the first entry in the list, returns NULL.
+ *
+ * Example:
+ * first = list_prev(&parent->children, second, list);
+ * if (!first)
+ * printf("Can't go back to first child?!\n");
+ */
+#define list_prev(h, i, member) \
+ ((list_typeof(i))list_entry_or_null(list_debug(h), \
+ (i)->member.prev, \
+ list_off_var_((i), member)))
+
/**
* list_append_list - empty one list onto the end of another.
* @to: the list to append into
(container_off_var(var, member) + \
check_type(var->member, struct list_node))
+#if HAVE_TYPEOF
+#define list_typeof(var) typeof(var)
+#else
+#define list_typeof(var) void *
+#endif
+
+/* Returns member, or NULL if at end of list. */
+static inline void *list_entry_or_null(struct list_head *h,
+ struct list_node *n,
+ size_t off)
+{
+ if (n == &h->n)
+ return NULL;
+ return (char *)n - off;
+}
#endif /* CCAN_LIST_H */