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Diffstat (limited to 'src/qt3support/tools/q3deepcopy.cpp')
-rw-r--r-- | src/qt3support/tools/q3deepcopy.cpp | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/src/qt3support/tools/q3deepcopy.cpp b/src/qt3support/tools/q3deepcopy.cpp new file mode 100644 index 0000000..c026021 --- /dev/null +++ b/src/qt3support/tools/q3deepcopy.cpp @@ -0,0 +1,123 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** Contact: Qt Software Information (qt-info@nokia.com) +** +** This file is part of the Qt3Support module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the either Technology Preview License Agreement or the +** Beta Release License Agreement. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 2.1 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 2.1 requirements +** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** In addition, as a special exception, Nokia gives you certain +** additional rights. These rights are described in the Nokia Qt LGPL +** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this +** package. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 3.0 as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU General Public License version 3.0 requirements will be +** met: http://www.gnu.org/copyleft/gpl.html. +** +** If you are unsure which license is appropriate for your use, please +** contact the sales department at qt-sales@nokia.com. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "q3deepcopy.h" + +QT_BEGIN_NAMESPACE + +/*! + \class Q3DeepCopy + \brief The Q3DeepCopy class is a template class which ensures that + implicitly shared and explicitly shared classes reference unique + data. + + \reentrant + + \compat + + Normally, shared copies reference the same data to optimize memory + use and for maximum speed. In the example below, \c s1, \c s2, \c + s3, \c s4 and \c s5 share data. + + \snippet doc/src/snippets/code/src_qt3support_tools_q3deepcopy.cpp 0 + + Q3DeepCopy can be used several ways to ensure that an object + references unique, unshared data. In the example below, \c s1, \c + s2 and \c s5 share data, while neither \c s3 nor \c s4 share data. + \snippet doc/src/snippets/code/src_qt3support_tools_q3deepcopy.cpp 1 + + In the example below, \c s1, \c s2 and \c s5 share data, and \c s3 + and \c s4 share data. + \snippet doc/src/snippets/code/src_qt3support_tools_q3deepcopy.cpp 2 + + Q3DeepCopy can also provide safety in multithreaded applications + that use shared classes. In the example below, the variable \c + global_string is used safely since the data contained in \c + global_string is always a deep copy. This ensures that all threads + get a unique copy of the data, and that any assignments to \c + global_string will result in a deep copy. + + \snippet doc/src/snippets/code/src_qt3support_tools_q3deepcopy.cpp 3 + + \warning It is the application developer's responsibility to + protect the object shared across multiple threads. + + The examples above use QString, which is an implicitly shared + class. The behavior of Q3DeepCopy is the same when using explicitly + shared classes like QByteArray. + + Currently, Q3DeepCopy works with the following classes: + \list + \i QMemArray (including subclasses like QByteArray and QCString) + \i QMap + \i QString + \i QValueList (including subclasses like QStringList and QValueStack) + \i QValueVector + \endlist + + \sa \link threads.html Thread Support in Qt \endlink +*/ + +/*! + \fn Q3DeepCopy::Q3DeepCopy() + + Constructs an empty instance of type \e T. +*/ + +/*! + \fn Q3DeepCopy::Q3DeepCopy( const T &t ) + + Constructs a deep copy of \a t. +*/ + +/*! + \fn Q3DeepCopy<T>& Q3DeepCopy::operator=( const T &t ) + + Assigns a deep copy of \a t. +*/ + +/*! + \fn Q3DeepCopy::operator T () + + Returns a deep copy of the encapsulated data. +*/ + +QT_END_NAMESPACE |