1/*
2 * Copyright (C) 2017 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#pragma once
27
28#include <wtf/Assertions.h>
29#include <wtf/StdLibExtras.h>
30
31namespace WTF {
32
33template<typename T>
34class SinglyLinkedListWithTail {
35public:
36 bool isEmpty() const { return !m_first; }
37
38 template<typename SetNextFunc>
39 void append(SetNextFunc&& setNextFunc, T* node)
40 {
41 if (!m_first) {
42 RELEASE_ASSERT(!m_last);
43 m_first = node;
44 m_last = node;
45 return;
46 }
47
48 std::forward<SetNextFunc>(setNextFunc)(m_last, node);
49 m_last = node;
50 }
51
52 T* first() const { return m_first; }
53 T* last() const { return m_last; }
54
55private:
56 T* m_first { nullptr };
57 T* m_last { nullptr };
58};
59
60} // namespace WTF
61
62using WTF::SinglyLinkedListWithTail;
63
64