From 15594f62fe76d986ebf10c1965798df5c8cc97fd Mon Sep 17 00:00:00 2001
From: Augustin Cavalier <waddlesplash@gmail.com>
Date: Fri, 27 Mar 2026 00:02:11 -0400
Subject: [PATCH] DoublyLinkedList: Make DoublyLinkedListCLink more useful.

Before, it just used a hardcoded Element::link member. Now,
it uses whatever one is specified based on the template
arguments.

No source compatibility breakage intended.

Change-Id: I62128921766df0b705488eb64402f902334f2ed0
Reviewed-on: https://review.haiku-os.org/c/haiku/+/10589
Reviewed-by: waddlesplash <waddlesplash@gmail.com>
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>
Haiku-Format: Haiku-format Bot <no-reply+haikuformatbot@haiku-os.org>
---
 headers/private/util/DoublyLinkedList.h | 27 +++++++++++++------------
 1 file changed, 14 insertions(+), 13 deletions(-)

diff --git a/headers/private/util/DoublyLinkedList.h b/headers/private/util/DoublyLinkedList.h
index 6194567e6e..622aa2b71d 100644
--- a/headers/private/util/DoublyLinkedList.h
+++ b/headers/private/util/DoublyLinkedList.h
@@ -83,22 +83,23 @@ public:
 	}
 };
 
-// DoublyLinkedListCLink - interface to struct list
-template<typename Element>
+// DoublyLinkedListCLink - interface to struct list (or equivalent)
+template<typename Element, typename CLink = struct list_link,
+	CLink Element::* LinkMember = &Element::link>
 class DoublyLinkedListCLink {
-	private:
-		typedef DoublyLinkedListLink<Element> Link;
+private:
+	typedef DoublyLinkedListLink<Element> Link;
 
-	public:
-		inline Link* operator()(Element* element) const
-		{
-			return (Link*)&element->link;
-		}
+public:
+	inline Link* operator()(Element* element) const
+	{
+		return (Link*)&(element->*LinkMember);
+	}
 
-		inline const Link* operator()(const Element* element) const
-		{
-			return (const Link*)&element->link;
-		}
+	inline const Link* operator()(const Element* element) const
+	{
+		return (Link*)&(element->*LinkMember);
+	}
 };
 
 // for convenience