| /**************************************************************************** |
| ** |
| ** Copyright (C) 2018 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Sérgio Martins <sergio.martins@kdab.com> |
| ** Copyright (C) 2019 The Qt Company Ltd. |
| ** Contact: https://www.qt.io/licensing/ |
| ** |
| ** This file is part of the QtCore module of the Qt Toolkit. |
| ** |
| ** $QT_BEGIN_LICENSE:LGPL$ |
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| ** GNU Lesser General Public License Usage |
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| ** General Public License version 3 as published by the Free Software |
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| ** |
| ** GNU General Public License Usage |
| ** Alternatively, this file may be used under the terms of the GNU |
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| ** Public license version 3 or any later version approved by the KDE Free |
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| ** $QT_END_LICENSE$ |
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| ****************************************************************************/ |
| |
| #ifndef QSCOPEGUARD_H |
| #define QSCOPEGUARD_H |
| |
| #include <QtCore/qglobal.h> |
| |
| #include <type_traits> |
| #include <utility> |
| |
| QT_BEGIN_NAMESPACE |
| |
| template <typename F> |
| class |
| #if __has_cpp_attribute(nodiscard) |
| // Q_REQUIRED_RESULT can be defined as __warn_unused_result__ or as [[nodiscard]] |
| // but the 1st one has some limitations for example can be placed only on functions. |
| Q_REQUIRED_RESULT |
| #endif |
| QScopeGuard |
| { |
| public: |
| explicit QScopeGuard(F &&f) noexcept |
| : m_func(std::move(f)) |
| { |
| } |
| |
| explicit QScopeGuard(const F &f) noexcept |
| : m_func(f) |
| { |
| } |
| |
| QScopeGuard(QScopeGuard &&other) noexcept |
| : m_func(std::move(other.m_func)) |
| , m_invoke(qExchange(other.m_invoke, false)) |
| { |
| } |
| |
| ~QScopeGuard() noexcept |
| { |
| if (m_invoke) |
| m_func(); |
| } |
| |
| void dismiss() noexcept |
| { |
| m_invoke = false; |
| } |
| |
| private: |
| Q_DISABLE_COPY(QScopeGuard) |
| |
| F m_func; |
| bool m_invoke = true; |
| }; |
| |
| #ifdef __cpp_deduction_guides |
| template <typename F> QScopeGuard(F(&)()) -> QScopeGuard<F(*)()>; |
| #endif |
| |
| //! [qScopeGuard] |
| template <typename F> |
| #if __has_cpp_attribute(nodiscard) |
| Q_REQUIRED_RESULT |
| #endif |
| QScopeGuard<typename std::decay<F>::type> qScopeGuard(F &&f) |
| { |
| return QScopeGuard<typename std::decay<F>::type>(std::forward<F>(f)); |
| } |
| |
| QT_END_NAMESPACE |
| |
| #endif // QSCOPEGUARD_H |