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Diffstat (limited to 'src/corelib/kernel/qpointer.cpp')
| -rw-r--r-- | src/corelib/kernel/qpointer.cpp | 285 |
1 files changed, 0 insertions, 285 deletions
diff --git a/src/corelib/kernel/qpointer.cpp b/src/corelib/kernel/qpointer.cpp deleted file mode 100644 index 737d73c4b8..0000000000 --- a/src/corelib/kernel/qpointer.cpp +++ /dev/null @@ -1,285 +0,0 @@ -/**************************************************************************** -** -** Copyright (C) 2016 The Qt Company Ltd. -** Contact: https://www.qt.io/licensing/ -** -** This file is part of the QtCore module of the Qt Toolkit. -** -** $QT_BEGIN_LICENSE:LGPL$ -** Commercial License Usage -** Licensees holding valid commercial Qt licenses may use this file in -** accordance with the commercial license agreement provided with the -** Software or, alternatively, in accordance with the terms contained in -** a written agreement between you and The Qt Company. For licensing terms -** and conditions see https://www.qt.io/terms-conditions. For further -** information use the contact form at https://www.qt.io/contact-us. -** -** GNU Lesser General Public License Usage -** Alternatively, this file may be used under the terms of the GNU Lesser -** General Public License version 3 as published by the Free Software -** Foundation and appearing in the file LICENSE.LGPL3 included in the -** packaging of this file. Please review the following information to -** ensure the GNU Lesser General Public License version 3 requirements -** will be met: https://www.gnu.org/licenses/lgpl-3.0.html. -** -** GNU General Public License Usage -** Alternatively, this file may be used under the terms of the GNU -** General Public License version 2.0 or (at your option) the GNU General -** Public license version 3 or any later version approved by the KDE Free -** Qt Foundation. The licenses are as published by the Free Software -** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3 -** included in the packaging of this file. Please review the following -** information to ensure the GNU General Public License requirements will -** be met: https://www.gnu.org/licenses/gpl-2.0.html and -** https://www.gnu.org/licenses/gpl-3.0.html. -** -** $QT_END_LICENSE$ -** -****************************************************************************/ - -/*! - \class QPointer - \inmodule QtCore - \brief The QPointer class is a template class that provides guarded pointers to QObject. - - \ingroup objectmodel - - A guarded pointer, QPointer<T>, behaves like a normal C++ - pointer \c{T *}, except that it is automatically cleared when the - referenced object is destroyed (unlike normal C++ pointers, which - become "dangling pointers" in such cases). \c T must be a - subclass of QObject. - - Guarded pointers are useful whenever you need to store a pointer - to a QObject that is owned by someone else, and therefore might be - destroyed while you still hold a reference to it. You can safely - test the pointer for validity. - - Note that Qt 5 introduces a slight change in behavior when using QPointer. - - \list - - \li When using QPointer on a QWidget (or a subclass of QWidget), previously - the QPointer would be cleared by the QWidget destructor. Now, the QPointer - is cleared by the QObject destructor (since this is when QWeakPointer objects are - cleared). Any QPointers tracking a widget will \b NOT be cleared before the - QWidget destructor destroys the children for the widget being tracked. - - \endlist - - Qt also provides QSharedPointer, an implementation of a reference-counted - shared pointer object, which can be used to maintain a collection of - references to an individual pointer. - - Example: - - \snippet pointer/pointer.cpp 0 - \dots - \snippet pointer/pointer.cpp 1 - \snippet pointer/pointer.cpp 2 - - If the QLabel is deleted in the meantime, the \c label variable - will hold \nullptr instead of an invalid address, and the last line will - never be executed. - - The functions and operators available with a QPointer are the - same as those available with a normal unguarded pointer, except - the pointer arithmetic operators (\c{+}, \c{-}, \c{++}, and - \c{--}), which are normally used only with arrays of objects. - - Use QPointers like normal pointers and you will not need to read - this class documentation. - - For creating guarded pointers, you can construct or assign to them - from a T* or from another guarded pointer of the same type. You - can compare them with each other using operator==() and - operator!=(), or test for \nullptr with isNull(). You can dereference - them using either the \c *x or the \c x->member notation. - - A guarded pointer will automatically cast to a \c T *, so you can - freely mix guarded and unguarded pointers. This means that if you - have a QPointer<QWidget>, you can pass it to a function that - requires a QWidget *. For this reason, it is of little value to - declare functions to take a QPointer as a parameter; just use - normal pointers. Use a QPointer when you are storing a pointer - over time. - - Note that class \c T must inherit QObject, or a compilation or - link error will result. - - \sa QSharedPointer, QObject, QObjectCleanupHandler -*/ - -/*! - \fn template <class T> QPointer<T>::QPointer() - - Constructs a guarded pointer with value \nullptr. - - \sa isNull() -*/ - -/*! - \fn template <class T> QPointer<T>::QPointer(T* p) - - Constructs a guarded pointer that points to the same object that \a p - points to. -*/ - -/*! - \fn template <class T> QPointer<T>::~QPointer() - - Destroys the guarded pointer. Just like a normal pointer, - destroying a guarded pointer does \e not destroy the object being - pointed to. -*/ - -/*! - \fn template <class T> void QPointer<T>::swap(QPointer &other) - \since 5.6 - - Swaps the contents of this QPointer with the contents of \a other. - This operation is very fast and never fails. -*/ - -/*! - \fn template <class T> QPointer<T> & QPointer<T>::operator=(T* p) - - Assignment operator. This guarded pointer will now point to the - same object that \a p points to. -*/ - -/*! - \fn template <class T> T* QPointer<T>::data() const - \since 4.4 - - Returns the pointer to the object being guarded. -*/ - -/*! - \fn template <class T> T* QPointer<T>::get() const - \since 6.0 - - Same as data(). This function is provided for STL compatibility. -*/ - -/*! - \fn template <class T> bool QPointer<T>::isNull() const - - Returns \c true if the referenced object has been destroyed or if - there is no referenced object; otherwise returns \c false. -*/ - -/*! - \fn template <class T> void QPointer<T>::clear() - \since 5.0 - - Clears this QPointer object. - - \sa isNull() -*/ - -/*! - \fn template <class T> T* QPointer<T>::operator->() const - - Overloaded arrow operator; implements pointer semantics. Just use - this operator as you would with a normal C++ pointer. -*/ - -/*! - \fn template <class T> T& QPointer<T>::operator*() const - - Dereference operator; implements pointer semantics. Just use this - operator as you would with a normal C++ pointer. -*/ - -/*! - \fn template <class T> QPointer<T>::operator T*() const - - Cast operator; implements pointer semantics. Because of this - function you can pass a QPointer\<T\> to a function where a T* - is required. -*/ - -/*! - \fn template <typename T, typename X> bool QPointer<T>::operator==(X *o, const QPointer<T> &p) - - Equality operator. Returns \c true if \a o and the guarded - pointer \a p are pointing to the same object, otherwise - returns \c false. - -*/ -/*! - \fn template <typename T, typename X> bool QPointer<T>::operator==(const QPointer<T> &p, X *o) - - Equality operator. Returns \c true if \a o and the guarded - pointer \a p are pointing to the same object, otherwise - returns \c false. - -*/ -/*! - \fn template <typename T, typename X> bool QPointer<T>::operator==(const QPointer<T> &p1, const QPointer<X> &p2) - - Equality operator. Returns \c true if the guarded pointers \a p1 and \a p2 - are pointing to the same object, otherwise - returns \c false. - -*/ -/*! - \fn template <typename T> bool QPointer<T>::operator==(std::nullptr_t, const QPointer<T> &rhs) - - Equality operator. Returns \c true if the pointer guarded by \a rhs - is \nullptr, otherwise - returns \c false. -*/ -/*! - \fn template <typename T> bool QPointer<T>::operator==(const QPointer<T> &lhs, std::nullptr_t) - - Equality operator. Returns \c true if the pointer guarded by \a lhs - is \nullptr, otherwise - returns \c false. -*/ - -/*! - \fn template <typename T, typename X> bool QPointer<T>::operator!=(const QPointer<T> &p, X *o) - - Inequality operator. Returns \c true if \a o and the guarded - pointer \a p are not pointing to the same object, otherwise - returns \c false. -*/ -/*! - \fn template <typename T, typename X> bool QPointer<T>::operator!=(X *o, const QPointer<T> &p) - - Inequality operator. Returns \c true if \a o and the guarded - pointer \a p are not pointing to the same object, otherwise - returns \c false. -*/ -/*! - \fn template <typename T, typename X> bool QPointer<T>::operator!=(const QPointer<T> &p1, const QPointer<X> &p2) - - Inequality operator. Returns \c true if the guarded pointers \a p1 and - \a p2 are not pointing to the same object, otherwise - returns \c false. -*/ -/*! - \fn template <typename T> bool QPointer<T>::operator!=(std::nullptr_t, const QPointer<T> &rhs) - - Inequality operator. Returns \c true if the pointer guarded by \a rhs is - a valid (ie not \nullptr) pointer, otherwise - returns \c false. -*/ -/*! - \fn template <typename T> bool QPointer<T>::operator!=(const QPointer<T> &lhs, std::nullptr_t) - - Inequality operator. Returns \c true if the pointer guarded by \a lhs is - a valid (ie not \nullptr) pointer, otherwise - returns \c false. -*/ - -/*! - \fn template <typename T> QPointer<T> qPointerFromVariant(const QVariant &variant) - - \internal - - Returns a guarded pointer that points to the same object that - \a variant holds. -*/ |