1 | /**************************************************************************** |
2 | ** |
3 | ** Copyright (C) 2018 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Sérgio Martins <sergio.martins@kdab.com> |
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25 | ** GNU General Public License Usage |
26 | ** Alternatively, this file may be used under the terms of the GNU |
27 | ** General Public License version 2.0 or (at your option) the GNU General |
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38 | ****************************************************************************/ |
39 | |
40 | #ifndef QSCOPEGUARD_H |
41 | #define QSCOPEGUARD_H |
42 | |
43 | #include <QtCore/qglobal.h> |
44 | |
45 | |
46 | QT_BEGIN_NAMESPACE |
47 | |
48 | |
49 | template <typename F> class QScopeGuard; |
50 | template <typename F> QScopeGuard<F> qScopeGuard(F f); |
51 | |
52 | template <typename F> |
53 | class |
54 | #if QT_HAS_CPP_ATTRIBUTE(nodiscard) |
55 | // Q_REQUIRED_RESULT can be defined as __warn_unused_result__ or as [[nodiscard]] |
56 | // but the 1st one has some limitations for example can be placed only on functions. |
57 | Q_REQUIRED_RESULT |
58 | #endif |
59 | QScopeGuard |
60 | { |
61 | public: |
62 | QScopeGuard(QScopeGuard &&other) noexcept |
63 | : m_func(std::move(other.m_func)) |
64 | , m_invoke(qExchange(other.m_invoke, false)) |
65 | { |
66 | } |
67 | |
68 | ~QScopeGuard() |
69 | { |
70 | if (m_invoke) |
71 | m_func(); |
72 | } |
73 | |
74 | void dismiss() noexcept |
75 | { |
76 | m_invoke = false; |
77 | } |
78 | |
79 | private: |
80 | explicit QScopeGuard(F &&f) noexcept |
81 | : m_func(std::move(f)) |
82 | { |
83 | } |
84 | |
85 | Q_DISABLE_COPY(QScopeGuard) |
86 | |
87 | F m_func; |
88 | bool m_invoke = true; |
89 | friend QScopeGuard qScopeGuard<F>(F); |
90 | }; |
91 | |
92 | |
93 | template <typename F> |
94 | #if QT_HAS_CPP_ATTRIBUTE(nodiscard) |
95 | Q_REQUIRED_RESULT |
96 | #endif |
97 | QScopeGuard<F> qScopeGuard(F f) |
98 | { |
99 | return QScopeGuard<F>(std::move(f)); |
100 | } |
101 | |
102 | QT_END_NAMESPACE |
103 | |
104 | #endif // QSCOPEGUARD_H |
105 | |