test/util/TestIntrusiveForwardList: add constant_time_size test

test/util/TestIntrusiveForwardList.cxx

@@ -32,7 +32,8 @@ TEST(IntrusiveForwardList, Basic)
 
 	Item items[]{'a', 'b', 'c'};
 
-	IntrusiveForwardList<CharItem> list;
+	using List = IntrusiveForwardList<CharItem>;
+	List list;
 	ASSERT_EQ(ToString(list), "");
 	list.reverse();
 	ASSERT_EQ(ToString(list), "");
@@ -49,6 +50,73 @@ TEST(IntrusiveForwardList, Basic)
 	ASSERT_EQ(ToString(list), "bc");
 	list.reverse();
 	ASSERT_EQ(ToString(list), "cb");
+
+	/* move constructor */
+	auto list2 = std::move(list);
+	ASSERT_EQ(ToString(list2), "cb");
+	ASSERT_EQ(ToString(list), "");
+
+	/* move operator */
+	list = std::move(list2);
+	ASSERT_EQ(ToString(list), "cb");
+	ASSERT_EQ(ToString(list2), "");
+
+	// insert_after()
+	List::insert_after(list.begin(), items[0]);
+	ASSERT_EQ(ToString(list), "cab");
+}
+
+TEST(IntrusiveForwardList, ConstantTimeSize)
+{
+	using Item = CharItem;
+
+	Item items[]{'a', 'b', 'c'};
+
+	IntrusiveForwardList<
+		CharItem, IntrusiveForwardListBaseHookTraits<CharItem>,
+		IntrusiveForwardListOptions{.constant_time_size = true}> list;
+	ASSERT_EQ(ToString(list), "");
+	ASSERT_EQ(list.size(), 0U);
+
+	list.reverse();
+	ASSERT_EQ(ToString(list), "");
+	ASSERT_EQ(list.size(), 0U);
+
+	for (auto &i : items)
+		list.push_front(i);
+
+	ASSERT_EQ(ToString(list), "cba");
+	ASSERT_EQ(list.size(), 3U);
+
+	list.reverse();
+	ASSERT_EQ(ToString(list), "abc");
+	ASSERT_EQ(list.size(), 3U);
+
+	list.pop_front();
+	ASSERT_EQ(ToString(list), "bc");
+	ASSERT_EQ(list.size(), 2U);
+	list.reverse();
+	ASSERT_EQ(ToString(list), "cb");
+	ASSERT_EQ(list.size(), 2U);
+
+	/* move constructor */
+	auto list2 = std::move(list);
+	ASSERT_EQ(ToString(list2), "cb");
+	ASSERT_EQ(list2.size(), 2U);
+	ASSERT_EQ(ToString(list), "");
+	ASSERT_EQ(list.size(), 0U);
+
+	/* move operator */
+	list = std::move(list2);
+	ASSERT_EQ(ToString(list), "cb");
+	ASSERT_EQ(list.size(), 2U);
+	ASSERT_EQ(ToString(list2), "");
+	ASSERT_EQ(list2.size(), 0U);
+
+	// insert_after()
+	list.insert_after(list.begin(), items[0]);
+	ASSERT_EQ(ToString(list), "cab");
+	ASSERT_EQ(list.size(), 3U);
 }
 
 TEST(IntrusiveForwardList, CacheLast)