src_corelib_tools_qscopedpointer.cpp

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// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
 
void myFunction(bool useSubClass)
{
    MyClass *p = useSubClass ? new MyClass() : new MySubClass;
    QIODevice *device = handsOverOwnership();
 
    if (m_value > 3) {
        delete p;
        delete device;
        return;
    }
 
    try {
        process(device);
    }
    catch (...) {
        delete p;
        delete device;
        throw;
    }
 
    delete p;
    delete device;
}
 
void myFunction(bool useSubClass)
{
    // assuming that MyClass has a virtual destructor
    QScopedPointer<MyClass> p(useSubClass ? new MyClass() : new MySubClass);
    QScopedPointer<QIODevice> device(handsOverOwnership());
 
    if (m_value > 3)
        return;
 
    process(device);
}
 
    const QWidget *const p = new QWidget();
    // is equivalent to:
    const QScopedPointer<const QWidget> p(new QWidget());
 
    QWidget *const p = new QWidget();
    // is equivalent to:
    const QScopedPointer<QWidget> p(new QWidget());
 
    const QWidget *p = new QWidget();
    // is equivalent to:
    QScopedPointer<const QWidget> p(new QWidget());
 
if (scopedPointer) {
    ...
}
 
class MyPrivateClass; // forward declare MyPrivateClass
 
class MyClass
{
private:
    QScopedPointer<MyPrivateClass> privatePtr; // QScopedPointer to forward declared class
 
public:
    MyClass(); // OK
    inline ~MyClass() {} // VIOLATION - Destructor must not be inline
 
private:
    Q_DISABLE_COPY(MyClass) // OK - copy constructor and assignment operators
                             // are now disabled, so the compiler won't implicitly
                             // generate them.
};
 
// this QScopedPointer deletes its data using the delete[] operator:
QScopedPointer<int, QScopedPointerArrayDeleter<int> > arrayPointer(new int[42]);
 
// this QScopedPointer frees its data using free():
QScopedPointer<int, QScopedPointerPodDeleter> podPointer(reinterpret_cast<int *>(malloc(42)));
 
// this struct calls "myCustomDeallocator" to delete the pointer
struct ScopedPointerCustomDeleter
{
    static inline void cleanup(MyCustomClass *pointer)
    {
        myCustomDeallocator(pointer);
    }
};
 
// QScopedPointer using a custom deleter:
QScopedPointer<MyCustomClass, ScopedPointerCustomDeleter> customPointer(new MyCustomClass);