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//! [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<QString> 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<QString>( s2 );  // s3 is a deep copy of s2
QString s4 = s3;                        // s4 is a shallow copy of s3
QString s5 = s2;
//! [2]


//! [3]
Q3DeepCopy<QString> 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]