qscopeguard.h

Go to the documentation of this file.

// 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.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
#ifndef QSCOPEGUARD_H
#define QSCOPEGUARD_H
 
#include <QtCore/qglobal.h>
 
#include <type_traits>
#include <utility>
 
QT_BEGIN_NAMESPACE
 
template <typename F>
class QScopeGuard
{
public:
    Q_NODISCARD_CTOR
    explicit QScopeGuard(F &&f) noexcept
        : m_func(std::move(f))
    {
    }
 
    Q_NODISCARD_CTOR
    explicit QScopeGuard(const F &f) noexcept
        : m_func(f)
    {
    }
 
    Q_NODISCARD_CTOR
    QScopeGuard(QScopeGuard &&other) noexcept
        : m_func(std::move(other.m_func))
        , m_invoke(std::exchange(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;
};
 
template <typename F> QScopeGuard(F(&)()) -> QScopeGuard<F(*)()>;
 
//! [qScopeGuard]
template <typename F>
[[nodiscard]] 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