See also QSharedPointer and QScopedPointer. This helps. h" class Controller { private : QSharedPointer<MyClass. const T *QSharedDataPointer:: constData constMake a typedef for QSharedPointer<UserDataType>, and use both Q_DECLARE_METATYPE as well as qRegisterMetaType() to register it for use. #include <QSharedPointer> #include <memory>. If this function can determine that the pointer has already been deleted, it returns nullptr . This function was introduced in Qt 4. In a related question: Waiting slots to be executed before quitting. 209: The pointer to the object is kept here because it needs to match the actual: 210: deleter function's parameters, regardless of what template argument the: 211: last QSharedPointer instance had. example, this allows calling QObject::deleteLater() on a given object. QSharedPointer is a smart pointer class in Qt that provides shared ownership of objects. 2 version on Ubuntu 18. C++ (Cpp) QSharedPointer::getEndPoint - 6 examples found. A more complex program sending QSharePointer objects using slots has a similar situation with GDB, that can be reproduced with the previous example. QList::contains algorithm is based on == operator. template<typename T >. 1 Creates a QSharedPointer object and allocates a new item of type \tt T. Each QCPAxis has an internal QCPAxisTicker (or a subclass) in order to generate tick positions and tick labels for the current axis range. One problem i have ran into is using signals and slots with the objects that are shared-pointed-to. QVector<T> used to be a different class in Qt 5, but is now a simple alias to QList. : new MyGizmo. Then, a new QSharedPointer object is created that references the same int object. QSharedPointer is a template class that allows multiple objects to share ownership of a dynamically allocated object. It is non-owning. data (); } When you delete the pointed-to object, data () will be null. #include <QSharedPointer> Note: All functions in this class are reentrant. You can rate examples to help us improve the quality of examples. See QWeakPointer::toStrongRef () for an example. [/quote] That is a good example to be careful with smart pointers. [/quote] That is a good example to be careful with smart pointers. The lifetime of an object begins after its constructor completes successfully. 4. So a conclusion would be: watch out for run-away. example, this allows calling QObject::deleteLater() on a given object. Navigation. 3 as published by the Free Software Foundation. QSharedPointer is Qt's own "smart pointer" to shared data, similar to. But in addition, QQueue provides three convenience functions. It behaves exactly. You can also use a data stream to read/write raw unencoded binary data. Commented defines are for "not compiling" parts. Before I use QSharedPointer, I am used to use forward declaration to declare my class instead of include its . There are several ways to avoid the problem in this particular example I can think of: change Test destructor to expect null m, write template template<typename T> inline T no_move (T&& tmp) {return tmp;}, explicitly create temporary Test object in assign, add getter for m and call it to force copying m (advised by Jarod42 ); MS Visual Studio. . The interface is straight forward, just the forward declaration of the private class and the. qRegisterMetaType< QSharedPointer<TestClass> >("SharedTestClass"); in main() not as a global variable. h","contentType":"file. Good day QT'ers, wondering if there's a better way to remove a QSharedPointer from a QList loaded with them. That means they should have a default constructor, a copy constructor, and an assignment operator. . The following custom cleanup handlers exist: QScopedPointerDeleter - the default, deletes the pointer using delete. combination used to implement implicit sharing, both in Qt itself and. But I've not seen it much in use in source code of Examples and Demos. Call doc:QSharedPointer :: data () to get a pointer to the referenced class; Make sure the QML engine doesn't assume ownership: doc:QDeclarativeEngine :: setObjectOwnership (P). > > I hope this can help you. You can rate examples to help us improve the quality of examples. The first MyClass object pointer 0x13defe0 is assigned to the QPointer instance, the second one (0x110f780) to QSharedPointer instance. The QSharedPointer class holds a strong reference to a shared pointer The QSharedPointer is an automatic, shared pointer in C++. If a ptr2's. If a ptr2's template parameter is different from a ptr1's, 1008. Equivalent to: QSharedPointer<T> other(t, deleter); this->swap(other); Returns true if the contained pointer is not nullptr. no known conversion for argument 1 from 'const RecordPtr {aka const QSharedPointer<MyApp::Record>}' to 'const QObject*' you are trying to pass an object of type RecordPtr to a method expecting "const QObject*". 5k 15 97 178. [quote author="situ117" date="1304279927"] I was reading about QSharedPointer in Qt. QSharedPointer:: objectCast() works reliably across DLL boundaries, but QSharedPointer:: dynamicCast() and std::dynamic_pointer_cast() don’t. You can rate examples to. Show Hide. You can rate examples to help us improve the quality of examples. Aug 27, 2015 at 15:02. But we don't use smart pointers in Qt much, due to parent-driven memory model. The extracted content is removed automatically once the last reference. I worked around this by extracting a raw pointer from the QSharedPointer: The template parameter is the type T of the class which QSharedPointer tracks. Having said that, without a perfect forwarding, using this function may be inefficient. You can rate examples to help us improve the quality of examples. Detailed Description. In this video series we will cover Qt 6. When the code block containing ptr2 ends, its reference. The problem is, that when implementing a QSharedAbstractItemModel, like the QAbstractListModel, you need to deal with raw pointers. Sabat 10 Jan 2020, 10:52. Qt로 프로그래밍할 때 메모리 관리 문제 (메모리 관리 불량으로 인한 메모리 누수 및 버그. The base class tick generator used by QCPAxis to create tick positions and tick labels. 4. QWeakPointer objects can only be created by assignment from a QSharedPointer. You might be tempted to use QSharedPointer in this case and it would work, but remember that QSharedPointer, just like std::shared_ptr, is a lot heavier construct, as sharing in a multi-threaded world is a "far from 0" overhead thing. It doesn't take ill luck: calling the destructor of an object that isn't alive is undefined behavior. For example i wanted to use a QsharedPointer<QStringListModel> instead of a QStringListModel* as a parameter for the function QListView::setModel. In that case, I think we should pass by reference. The following chapters show an example and explain a few important details regarding the functionality and limits of the implementation. 1 under Ubuntu 10. Values stored in Qt containers should be of assignable data types. To complicate it even more, all debugging traces were leading to. all provide a data() function to access the underlying data of a Qt class. qt. Check your Options in the drop-down menu of this sections header. You can rate examples to help us improve the quality of examples. I suspect the reason why T* operator doesn't exist is because there's the T* data() function which, like many of the other Qt classes such as QString, QByteArray etc. Detailed Description. QSharedPointer works with forward declarations, so I'd guess you're using it incorrectly; consider giving a minimal example that can be compiled (and more importantly doesn't require us to guess about the types). Their main advantage is reducing memory leaks and bugs due to poor memory management. The one I used in my own answer does. The normal pattern is to put the new statement inside the smart pointer's constructor, like this: QSharedPointer<Obj> p (new Obj (2)); That way you never have a reference to the naked pointer itself. To avoid passing raw pointers around I have changed all occurrences of DataProvider * to QSharedPointer<DataProvider>. The QWeakPointer is an automatic weak reference to a pointer in C++. ) method. Frequently Used Methods. >> I'm trying to use QMap/QHash with QSharedPointer with no success. See QWeakPointer::toStrongRef() for an example. This is not only about the Qt framework but also the STL in general. QSharedPointer holds a shared pointer by means of an external reference count (i. MyClass * myIns = new MyClass (); QSharedPointer<MyClass> asp ( myIns); QVariant aVariant = QVariant::fromValue( asp); To copy to clipboard, switch view to plain text mode. QSharedPointer is a smart pointer class in the Qt library. For example, if you need to find all unique shared_ptr from a vector, you need such a predicate. 12. It behaves exactly like a normal pointer for normal purposes, including respect for constness. . One example may be the case where you store lots of pointers to objects in a container class. The examples on Wikipedia makes no sense to me. Examples at hotexamples. Detailed Description. A slot is a receiving function used to get information about state changes in other widgets. These are the top rated real world C++ (Cpp) examples of QSharedPointer::GetFormulaRadius extracted from open source projects. The QSharedPointer is an automatic, shared pointer in C++. – Igor Tandetnik. This project implements the Event and BlockingQueue in two. See QWeakPointer::toStrongRef() for an example. 4. C++ (Cpp) QSharedPointer::getShapes - 4 examples found. Qt is quite older than the recent C++ standard, hence it was not available till Qt. The temporary instance of the shared pointer allocated on the heap in answer1 will be deallocated by its shared pointer. The QSharedPointer is an automatic, shared pointer in C++. The Qt documentation suggests that using the QSharedDataPointer with a visible implementation of its inferior is not typical. You can rate examples to help us improve the quality of examples. 1009. In the example above, the template specialization for the clone() function calls the EmployeeData::clone() virtual function. See Customizing QFrame for an example. @Yakk: Thanks for that, I've updated my answer to reflect your point. The QSharedPointer is an automatic, shared pointer in C++. Several shared_ptr objects may own the same object. For example, when saving the plot to disk. Example usage - #include <QSharedData> #include <QString> class EmployeeData : public QSharedData { public: EmployeeData() : id(-1) { } EmployeeData(const EmployeeData &other) : QSharedData(other), id(other. Since that method takes a QSharedPointer<QCPAxisTicker>,. If somehow the object/container survives so does the smart pointer and the allocated memory. std::shared_ptr<Exercise> americanExercise = std::make_shared<AmericanExercise> (settlementDate, in. 1 Answer. Programming Language: C++ (Cpp) Class/Type: QSharedPointer. The requester class should also be in charge of managing the memory of the pointer it created. It behaves exactly like a normal pointer for normal purposes, including respect for constness. These are the top rated real world C++ (Cpp) examples of QSharedPointer::isSelected extracted from open source projects. append(QSharedPointer<MyObject>(new MyObject("first", 1))); list. When the last associated QSharedPointer goes out of scope, the object will be deleted. For example "sample: 45 2048". In this installment, we will look at how to use Open Asset Import Library (Assimp) (1) to load 3D models from some common 3D model formats. T must be a subclass of QObject. QSharedPointer. . 27. It behaves exactly like a normal pointer for normal purposes, including respect for constness. This being the case, you have two ways around the problem: 1) Provide a copy constructor (which you have done) 2) Provide a specialization of qMetaTypeConstructHelper that doesn't use the copy constructor: template <> void *qMetaTypeConstructHelper<ClassA> (const ClassA *) { return new ClassA (); } Share. QSharedPointer: pointer 0x2384d70 already has reference counting Which at the very least gives us a basic idea that there is something wrong, and it involves a QSharedPointer. list. at (x); Then I pass it around and do the work, then the pointer dies but I have an extra one in the list so everything's fine, right? I noticed the destructor of MyClass is. 1. here is a. See also isNull(). It behaves exactly like a normal pointer for normal purposes, including respect for constness. // OK QSharedPointer < QObject > object3(new QObject); // OK} Using a Mutex to Protect the Integrity of Data. The problem is, that when implementing a QSharedAbstractItemModel, like the QAbstractListModel, you need to deal with raw pointers. A simple code that could reproduce the issue. It behaves exactly like a normal pointer for normal purposes, including respect for constness. wysota. It has a concept of ownership. MyObject * object; // Subclass of QObject. to ensure that the pointers being compared are equal. com: 30. QScopedPointer intentionally has no copy constructor or assignment operator, such that ownership and. That said, your stack trace is really strange:. . The Qt docs say that Q_DECLARE_METATYPE is necessary in case one has a connect being a queued connection. If a ptr2's template parameter is different from a ptr1's, 1008. For example, using data() for QObject::connect() would be save, but. If you need a QSharedPointer, don't set the parent. A class derived from EmployeeData could override that function and return the. Example#1. But you might miss the more convenient BlockingQueue in Java/Python. If somehow the object/container survives so does the smart pointer and the allocated memory. A public static factory method returning in this case QSharedPointer; A private deleter class that is a friend of class A; Here is an example using boost::shared_ptr (I do not have a QT installation right now, but you should be able to just replace all instances of boost::shared_ptr with QSharedPointer)It is somehow reasonable to use QSharedPointer here. You can use smart pointers to hold you item in your QList, for example QSharedPointer<MyCustomObj>. See also QSharedPointer and QScopedPointer. [/quote] Correct. Neither of your approaches is thread-safe. In your example "going out of scope" is happening when closing brace of main () function is encountered. I want to prevent something as this: Qt Code: Switch view. 1 Answer. There are not so much Qt examples and demos with QSharedPointer because of the general concept for memory management in Qt using parent–child hierarchy of QObject. If T is a derived type of the template parameter of this class, QSharedPointer will perform an automatic cast. QSharedPointer<MyDataQObject> objPtr { new MyDataQObject, &QObject. So a conclusion would be: watch out for run-away. I am using Qt 5. To avoid the cost of thread creation, a thread pool can be used. These are the top rated real world C++ (Cpp) examples of QSharedPointer::node extracted from open source projects. If the receiver needs a reference of the sender object, it should retain it in a smart pointer. It is usually best to use a mutex with a QMutexLocker since this makes it easy to ensure that locking and unlocking are performed consistently. It's a start. The QSharedPointer is an automatic, shared pointer in C++. behaves exactly like a normal pointer for normal purposes, including respect for constness. T *QWeakPointer:: data const. The procedure is: Define the class Employee to have a single data member of type QSharedDataPointer<EmployeeData>. 1 Answer. typedef QVector<QSharedPointer<Tester> > TestPointerVector;. It behaves exactly like a normal pointer for normal purposes, including respect for constness. But in addition, QQueue provides three convenience functions. A QSharedPointer object can be created from a. 4, but was reborn in 4. 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. It cannot be used to dereference the pointer directly, but it can be used to verify if the pointer has been deleted or not in another context. The QCPGraphDataContainer is an abstract data container of QCPGraphData object, one of which will be created for each data point that we parse. 1 Reply Last reply . It has all the features you may want in a modern pointer class: it is polymorphic, it supports static, const, and dynamic casts, it implements atomic reference-counting and thread-safe semantics, it supports custom. When using QSharedPointer to a const object that is derived from QObject the metatyping is trying to register a conversion from const to non-const. The Q_DECLARE_METATYPE macro is necessary in both cases. Also, this Q_DECLARE_METATYPE(SharedTestClass) shouldn't be needed. C++ Class Qt 스마트 포인터 (QSharedPointer, QScopedPointer, QPointer) 스마트 포인터는 C++표준 포인터의 모든 기능을 가지고 있으며 자동 가비지 컬렉션 기능을 제공하는 클래스이다. Immediately after construction both pointers go out of scope. Frequently Used Methods. The memory corruption can happen if Team object is destroyed before reading its pointer from QMap. QPointer:: ~QPointer () Destroys the guarded pointer. Args> QSharedPointer<T> QSharedPointer<T>::create(Args &&. The problem is that this code is creating a QSharedPointer from a raw pointer, which implies ownership of the object pointed to. Use qSharedPointerCast (): QSharedPointer <Switch> mySwitchTest= qSharedPointerCast<Switch> (myState); Or call staticCast () on the smart pointer: QSharedPointer <Switch> mySwitchTest= myState. . The lifetime of an object begins after its constructor completes successfully. QList<T> is one of Qt's generic container classes. If the reference count is zero then the object it is pointing to will be destroyed. All these news and deletes bothered me when I started in Qt, and I tried to stick to how I did it in gtkmm before. QWeakPointer objects can only be created by assignment from a QSharedPointer. Assume that we have T convert_func (const QJsonValue& value),. The content is extracted recursively to a temporary folder. 1 Answer. It does not manage the object it points to. So, at least, QList and QVector can be filled with it (I am not trying to find high-speed approach). Smart pointers with PythonQt. QSharedPointer는 다른 QSharedPointer 객체가 이를 참조하지 않는 한 범위를 벗어날 때 보유하고 있는 포인터를 삭제합니다. You shouldn't do that even from C++. This can be achieved by setting enabled to false before issuing a command like QCustomPlot::savePng, and setting enabled back to true afterwards. QSharedPointer<QMap<int, bool>> mpsptr = QSharedPointer<QMap<int, bool>>::create (QMap<int, bool> { {1, false}}); Ok, I found an answer that works for me. C++ (Cpp) QSharedPointer::isSelected - 12 examples found. See also QSharedPointer and QScopedPointer. Unfortunately Google was unable to help me this time. Share. Detailed Description. One problem i have ran into is using signals and slots with the objects that are shared-pointed-to. It has all the features you may want in a modern pointer class: it is polymorphic, it supports static, const, and dynamic casts, it implements atomic reference-counting and thread-safe semantics, it supports. A base class that allows obtaining a QSharedPointer for an object already managed by a shared pointer. Commented defines are for "not compiling" parts. _pointer = QSharedPointer<APIRequest> (this);For example: @ QSharedPointer<QToolButton>(new QToolButton);@ I have been trying to make this work properly within a psuedo widget factory i have made( as the application has thousands of widgets) and I want to make sure that the memory is de-allocated properly. The QSharedPointer is an automatic, shared pointer in C++. QPointer is not a smart pointer. List of all members, including inherited members; Public FunctionsA "null" QSharedPointer wraps a T* t where t equals 0/NULL/nullptr. I'm dealing with a large image and am doing several different processes on the QImage. 4. Usually one puts this (note that the typedefed name is used as string argument): qRegisterMetaType< QSharedPointer >("SharedTestClass"); in main() not as a global variable. Purpose. It behaves exactly like a normal pointer for normal purposes, including. removeAll(dataPoint01); }. Any pointer class which takes responsibility for the lifetime of the object it points to is considered a smart pointer. A minimal example: Q_DECLARE_METATYPE(QSharedPointer<const QObject>);One example may be the case where you store lots of pointers to objects in a container class. h","path":"src/corelib/tools/qalgorithms. This is the type of the shared data object. bool operator== ( const QSharedPointer & ptr1, const QSharedPointer & ptr2 ) Returns true if the pointer referenced by ptr1 is the same pointer as that referenced by ptr2. I was reading about QSharedPointer in Qt. 0. For. 이는 불변성에 대한 존중을 포함하여 일반적인 목적을 위한 일반 포인터와 똑같이 동작합니다. e. Define the EmployeeData class derived from. Make a typedef for QSharedPointer<UserDataType>, and use both Q_DECLARE_METATYPE as well as qRegisterMetaType () to register it for use. The QSharedPointer is an automatic, shared pointer in C++. This is the same as vector. See QWeakPointer::toStrongRef() for an example. Otherwise, the object deletes itself after emitting the signal. If used in this way, you can pass around these references and use them like pointers, and. keyToAscii (key). Now I have a situation in which a class has to call a function and pass a pointer to itself. The receiver reads the result data. publicslots: void slotCalledByScript(Y *managedBySharedPointer) { QSharedPointer<Y> yPtr =. . I have QList<QSharedPointer<MyClass>>. These are the top rated real world C++ (Cpp) examples of QSharedPointer::GetCenter extracted from open source projects. As reference the example tested on cross environment using GDB:Here is a minimal example: #include <QSharedPointer> struct A {}; int main(int argc, char *argv[]) { auto ca = QSharedPointer<const A>::create(); return 0; } Here is one file (not minimal) example but with few working cases, 2 not working and a debug. centralwidget = std::make_shared<QWidget> (MainWindow); verticalLayout = std::make_shared<QVBoxLayout> (centralwidget. Features such as make_shared strictly rely on the perfect forwarding feature, which is only available since C++11 and the introduction of universal (forwarding) references. For some reason, there are very few examples out there on how to use QSharedPointer, so i find myself posting here. QSharedPointer will delete the pointer it is holding when it goes out of scope, provided no other QSharedPointer objects are referencing it. 212: 213: This class is never instantiated directly: the constructors and: 214In the example above, the template specialization for the clone() function calls the EmployeeData::clone() virtual function. QSharedPointer will delete the pointer it is holding when it goes. Since the replicas have the same properties, signals, and slots as were. QSharedPointer will delete the pointer it is holding when it goes out of scope, provided no other. re. Fraction frac13 Fraction frac24 4 double d frac 5 QString fs frac 6 cout fs fs d from COS 2614 at University of South AfricaProposed Change: Have the class making the request create a QQuickItemGrabResult pointer itself, set all the dependencies, connect to all of its signals and then start the request. The index is used by item views, delegates, and selection models to locate an item in the model. This step is necessary since the only other way of keeping the engine from assuming ownership would be to give the object a parent, which is out of the question since. name) { } ~EmployeeData() { } For QSharedPointer The QSharedPointer is an automatic, shared pointer in C++. Also, this Q_DECLARE_METATYPE(SharedTestClass) shouldn't be needed. The QSharedPointer is an automatic, shared pointer in C++. So the point is: don't use QSharedPointer just because it's smart. If you look at the function definition, you'll see there is just one version : bool QMetaObject::invokeMethod ( QObject * obj, const char * member, QGenericArgument val0 = QGenericArgument ( 0 ), QGenericArgument val1 = QGenericArgument (), QGenericArgument val2 = QGenericArgument (),. Is it a good idea to use a QSharedPointer or a QScopedPointer to handle widgets? For example: @. QSharedPointer<MyClass> mc (new MyClass ()); mc->testSharedThis (); QScopedPointer's second template parameter can be used for custom cleanup handlers. template <typename InputIterator>. A shared pointer holds an instance to an object that manages its own lifetime and QObjects don't!Their. A guarded pointer, QPointer<T>, behaves like a normal C++ pointer T *, except that it is automatically set to 0 when the referenced object is destroyed (unlike normal C++ pointers, which become "dangling pointers" in such cases). maturity); by now, standard-library shared pointers are by far the. These are the top rated real world C++ (Cpp) examples of QSharedPointer::isSelected extracted from open source projects. Share. Therefore you have to create you smart pointer instance like this: auto obj=QSharedPointer<MyCustomObj>(new MyCustomObj,. The QWeakPointer is an automatic weak reference to a pointer in C++. Naively. QSharedPointer will delete the pointer it is holding when it goes out of scope, provided no other QSharedPointer objects are referencing it. Ah, when the function actually needs to manipulate the smart pointer itself. If you want to actually delete a mutex, you have to remove it from the mutexes mapping. I'd like to fill QSharedPointer<T> collection from QJsonArray (serialized Q_GADGETS) instance using universal function (template). This function was introduced in Qt 4. h","contentType":"file. The QSharedPointer is an automatic, shared pointer in C++. Also, this Q_DECLARE_METATYPE(SharedTestClass) shouldn't be needed. It does not manage the object it points to. Use qSharedPointerCast (): QSharedPointer <Switch> mySwitchTest= qSharedPointerCast<Switch> (myState); Or call staticCast () on the smart pointer: QSharedPointer <Switch> mySwitchTest= myState. When the code block containing ptr2 ends, its reference. Actually, it does so in examples setting custom deleter to Object::deleteLater . The problem boiled down to unexpected crashes occurring on random basis. QSharedPointer is a smart. See QWeakPointer::toStrongRef() for an example. The code the compiler generates for QScopedPointer is the same as when writing it manually. referencing it. 1010. 212: 213: This class is never instantiated directly: the constructors and: 214 In the example above, the template specialization for the clone() function calls the EmployeeData::clone() virtual function. This is useful, for instance, for calling deleteLater () on a QObject instead: QSharedPointer<MyObject> obj = QSharedPointer<MyObject> (new MyObject, &QObject::deleteLater); An alternative is using QPointer instead of QSharedPointer, citing the documentation: The QPointer class is a template class that provides guarded. QPointer is not a smart pointer. There are not so much Qt examples and demos with QSharedPointer because of the general concept for memory management in Qt using parent–child hierarchy of QObject. Copy assigns from other and returns a reference to this object. Looking for examples of natural languages with affricates but no corresponding fricatives/plosivesMember Function Documentation QSharedPointer < T > QEnableSharedFromThis:: sharedFromThis (). An. C++ (Cpp) QSharedPointer::GetFormulaRadius - 2 examples found. The same question about Qt equivalent - QSharedPointer. 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. To complicate things, debugging reports had absolutely random pattern as well. The Qt docs say that Q_DECLARE_METATYPE is necessary in case one has a connect being a queued connection. My app uses QSharedPointers throughout the C++ API, where instead of returning an object, it usually returns a smart pointer to it and every class has an accompanying typedef for convenience. This function was introduced in Qt 5. qRegisterMetaType< QSharedPointer<TestClass> >("SharedTestClass"); in main() not as a global variable. The QSharedPointer internals and the object are allocated in one single memory allocation, which could help reduce memory fragmentation in a long-running application. In the example above, the template specialization for the clone() function calls the EmployeeData::clone() virtual function. QSharedPointer IF you using a pointer and start giving pointer to other functions and you are passing your pointer all over. For large vectors, this operation can be slow (linear time), because it requires moving all the items in the vector by one position further in memory. Smart pointers facilitate the dynamic memory operations. As a iOS developer, I use a kind of smart pointers with reference counting implemented in NSObject whereby Im able to retain and release pointers when needed. Member Function Documentation QWeakPointer:: QWeakPointer (). 19. Also, by overloading the operator, it's very easy to. QSharedPointer:: objectCast() works reliably across DLL boundaries, but QSharedPointer:: dynamicCast() and std::dynamic_pointer_cast() don’t. C++ (Cpp) QSharedPointer::direction - 6 examples found. A class derived from EmployeeData could override that function and return the proper polymorphic type. One place we have used QSharedPointer is in DataObjectTableModel, shown in Example 13. C++ (Cpp) QSharedPointer::GetSubscriptionTypeStr - 2 examples found.