From 7475e971bc4271351966c645eee51e385a3b4915 Mon Sep 17 00:00:00 2001
From: Max Kellermann <mk@cm4all.com>
Date: Thu, 1 Dec 2022 18:40:44 +0100
Subject: [PATCH] util/IntrusiveList: remove_and_dispose_if() returns the
 number of removed items

---
 src/util/IntrusiveList.hxx | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/src/util/IntrusiveList.hxx b/src/util/IntrusiveList.hxx
index 183e98c93..7d0a5f310 100644
--- a/src/util/IntrusiveList.hxx
+++ b/src/util/IntrusiveList.hxx
@@ -296,8 +296,13 @@ public:
 		}
 	}
 
-	void remove_and_dispose_if(Predicate<const_reference> auto pred,
-				   Disposer<value_type> auto dispose) noexcept {
+	/**
+	 * @return the number of removed items
+	 */
+	std::size_t remove_and_dispose_if(Predicate<const_reference> auto pred,
+					  Disposer<value_type> auto dispose) noexcept {
+		std::size_t result = 0;
+
 		auto *n = head.next;
 
 		while (n != &head) {
@@ -308,8 +313,11 @@ public:
 				ToHook(*i).unlink();
 				--counter;
 				dispose(i);
+				++result;
 			}
 		}
+
+		return result;
 	}
 
 	const_reference front() const noexcept {