/**************************************************************************** ** ** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies). ** All rights reserved. ** Contact: Nokia Corporation (qt-info@nokia.com) ** ** This file is part of the documentation of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:BSD$ ** 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 Nokia Corporation and its Subsidiary(-ies) 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] // all 5 strings share the same data QString s1 = "abcd"; QString s2 = s1; QString s3 = s2; QString s4 = s3; QString s5 = s2; //! [0] //! [1] // s1, s2 and s5 share the same data, neither s3 nor s4 are shared QString s1 = "abcd"; QString s2 = s1; Q3DeepCopy s3 = s2; // s3 is a deep copy of s2 QString s4 = s3; // s4 is a deep copy of s3 QString s5 = s2; //! [1] //! [2] // s1, s2 and s5 share the same data, s3 and s4 share the same data QString s1 = "abcd"; QString s2 = s1; QString s3 = Q3DeepCopy( s2 ); // s3 is a deep copy of s2 QString s4 = s3; // s4 is a shallow copy of s3 QString s5 = s2; //! [2] //! [3] Q3DeepCopy global_string; // global string data QMutex global_mutex; // mutex to protext global_string ... void setGlobalString( const QString &str ) { global_mutex.lock(); global_string = str; // global_string is a deep copy of str global_mutex.unlock(); } ... void MyThread::run() { global_mutex.lock(); QString str = global_string; // str is a deep copy of global_string global_mutex.unlock(); // process the string data ... // update global_string setGlobalString( str ); } //! [3]