/**************************************************************************** ** ** Copyright (C) 2016 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] struct MyStruct { int i; ... }; Q_DECLARE_METATYPE(MyStruct) //! [0] //! [1] namespace MyNamespace { ... } Q_DECLARE_METATYPE(MyNamespace::MyStruct) //! [1] //! [2] MyStruct s; QVariant var; var.setValue(s); // copy s into the variant ... // retrieve the value MyStruct s2 = var.value(); //! [2] //! [3] int id = QMetaType::type("MyClass"); if (id != QMetaType::UnknownType) { void *myClassPtr = QMetaType::create(id); ... QMetaType::destroy(id, myClassPtr); myClassPtr = 0; } //! [3] //! [4] qRegisterMetaType("MyClass"); //! [4] //! [5] qRegisterMetaTypeStreamOperators("MyClass"); //! [5] //! [6] QDataStream &operator<<(QDataStream &out, const MyClass &myObj); QDataStream &operator>>(QDataStream &in, MyClass &myObj); //! [6] //! [7] int id = qRegisterMetaType(); //! [7] //! [8] int id = qMetaTypeId(); // id is now QMetaType::QString id = qMetaTypeId(); // compile error if MyStruct not declared //! [8] //! [9] typedef QString CustomString; qRegisterMetaType("CustomString"); //! [9] //! [10] #include Q_DECLARE_SEQUENTIAL_CONTAINER_METATYPE(std::deque) void someFunc() { std::deque container; QVariant var = QVariant::fromValue(container); // ... } //! [10] //! [11] #include Q_DECLARE_ASSOCIATIVE_CONTAINER_METATYPE(std::unordered_map) void someFunc() { std::unordered_map container; QVariant var = QVariant::fromValue(container); // ... } //! [11] //! [12] QPointer fp(new QFile); QVariant var = QVariant::fromValue(fp); // ... if (var.canConvert()) { QObject *sp = var.value(); qDebug() << sp->metaObject()->className(); // Prints 'QFile'. } //! [12] //! [13] #include Q_DECLARE_SMART_POINTER_METATYPE(std::shared_ptr) void someFunc() { auto smart_ptr = std::make_shared(); QVariant var = QVariant::fromValue(smart_ptr); // ... if (var.canConvert()) { QObject *sp = var.value(); qDebug() << sp->metaObject()->className(); // Prints 'QFile'. } } //! [13]