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+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the documentation of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** 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.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+** * Redistributions of source code must retain the above copyright
+** notice, this list of conditions and the following disclaimer.
+** * Redistributions in binary form must reproduce the above copyright
+** notice, this list of conditions and the following disclaimer in
+** the documentation and/or other materials provided with the
+** distribution.
+** * Neither the name of The Qt Company Ltd nor the names of its
+** contributors may be used to endorse or promote products derived
+** from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+//! [0]
+ class Y: public QEnableSharedFromThis<Y>
+ {
+ public:
+ QSharedPointer<Y> f()
+ {
+ return sharedFromThis();
+ }
+ };
+
+ int main()
+ {
+ QSharedPointer<Y> p(new Y());
+ QSharedPointer<Y> y = p->f();
+ Q_ASSERT(p == y); // p and q must share ownership
+ }
+//! [0]
+
+//! [1]
+ class ScriptInterface : public QObject
+ {
+ Q_OBJECT
+
+ // ...
+
+ public slots:
+ void slotCalledByScript(Y *managedBySharedPointer)
+ {
+ QSharedPointer<Y> yPtr = managedBySharedPointer->sharedFromThis();
+ // Some other code unrelated to scripts that expects a QSharedPointer<Y> ...
+ }
+ };
+//! [1]
+
+//! [2]
+ static void doDeleteLater(MyObject *obj)
+ {
+ obj->deleteLater();
+ }
+
+ void otherFunction()
+ {
+ QSharedPointer<MyObject> obj =
+ QSharedPointer<MyObject>(new MyObject, doDeleteLater);
+
+ // continue using obj
+ obj.clear(); // calls obj->deleteLater();
+ }
+//! [2]
+
+//! [3]
+ QSharedPointer<MyObject> obj =
+ QSharedPointer<MyObject>(new MyObject, &QObject::deleteLater);
+//! [3]
+
+//! [4]
+ if (sharedptr) { ... }
+//! [4]
+
+//! [5]
+ if (!sharedptr) { ... }
+//! [5]
+
+//! [6]
+ QSharedPointer<T> other(t); this->swap(other);
+//! [6]
+
+//! [7]
+ QSharedPointer<T> other(t, deleter); this->swap(other);
+//! [7]
+
+//! [8]
+ if (weakref) { ... }
+//! [8]
+
+//! [9]
+ if (!weakref) { ... }
+//! [9]
+
+//! [10]
+ qDebug("Tracking %p", weakref.data());
+//! [10]
+
+//! [11]
+ // this pointer cannot be used in another thread
+ // so other threads cannot delete it
+ QWeakPointer<int> weakref = obtainReference();
+
+ Object *obj = weakref.data();
+ if (obj) {
+ // if the pointer wasn't deleted yet, we know it can't get
+ // deleted by our own code here nor the functions we call
+ otherFunction(obj);
+ }
+//! [11]
+
+//! [12]
+ QWeakPointer<int> weakref;
+
+ // ...
+
+ QSharedPointer<int> strong = weakref.toStrongRef();
+ if (strong)
+ qDebug() << "The value is:" << *strong;
+ else
+ qDebug() << "The value has already been deleted";
+//! [12]