1/*
2 * Copyright (C) 2016 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. AND ITS CONTRIBUTORS ``AS IS''
14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
23 * THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#pragma once
27
28#include <type_traits>
29#include <wtf/StdLibExtras.h>
30
31// Based on http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0052r2.pdf
32
33namespace WTF {
34
35template<typename ExitFunction>
36class ScopeExit final {
37public:
38 template<typename ExitFunctionParameter>
39 explicit ScopeExit(ExitFunctionParameter&& exitFunction)
40 : m_exitFunction(WTFMove(exitFunction))
41 {
42 }
43
44 ScopeExit(ScopeExit&& other)
45 : m_exitFunction(WTFMove(other.m_exitFunction))
46 , m_executeOnDestruction(std::exchange(other.m_executeOnDestruction, false))
47 {
48 }
49
50 ~ScopeExit()
51 {
52 if (m_executeOnDestruction)
53 m_exitFunction();
54 }
55
56 void release()
57 {
58 m_executeOnDestruction = false;
59 }
60
61 ScopeExit(const ScopeExit&) = delete;
62 ScopeExit& operator=(const ScopeExit&) = delete;
63 ScopeExit& operator=(ScopeExit&&) = delete;
64
65private:
66 ExitFunction m_exitFunction;
67 bool m_executeOnDestruction { true };
68};
69
70template<typename ExitFunction>
71ScopeExit<ExitFunction> makeScopeExit(ExitFunction&& exitFunction)
72{
73 return ScopeExit<ExitFunction>(std::forward<ExitFunction>(exitFunction));
74}
75
76}
77
78using WTF::ScopeExit;
79using WTF::makeScopeExit;
80