shl: dlist: add _first/_last helpers

These helpers return the first and last elements respectively.

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>

diff --git a/src/shl_dlist.h b/src/shl_dlist.h
index c1d4beb..9e30dc5 100644 (file)
--- a/src/shl_dlist.h
+++ b/src/shl_dlist.h
@@ -102,6 +102,12 @@ static inline bool shl_dlist_empty(struct shl_dlist *head)
 #define shl_dlist_entry(ptr, type, member) \
        shl_offsetof((ptr), type, member)
 
+#define shl_dlist_first(head, type, member) \
+       shl_dlist_entry((head)->next, type, member)
+
+#define shl_dlist_last(head, type, member) \
+       shl_dlist_entry((head)->prev, type, member)
+
 #define shl_dlist_for_each(iter, head) \
        for (iter = (head)->next; iter != (head); iter = iter->next)