I need to store/get pointer to raw data

here my test code

Qt Code: 
  1. #include <QtCore>
  2. #include <QtGui>
  3. #include "qttest.h"
  4. #include <string.h>
  5. #include <stdio.h>
  6.  
  7.  
  8. qttest::qttest(QWidget *parent, Qt::WFlags flags)
  9. 	: QDialog(parent, flags)
  10. {
  11. 	ui.setupUi(this);
  12. 	ui.treeWidget->setHeaderLabels(QStringList() << "#" << "Name" << "Count" );
  13. 	QTreeWidgetItem *item =0;
  14. 	for(int i=0;i<50;i++){
  15. 		item = new QTreeWidgetItem(ui.treeWidget);
  16. 		item->setText(0,QString::number(i));
  17. 		item->setText(1,tr("Item %1").arg(i) );
  18. 		//item->setToolTip(1,"<b>hello's <br>QT</b>");
  19. 		unsigned char *data = new unsigned char [1024];
  20. 		strcpy((char*)data,"Hello world");
  21. 		item->setData(0,Qt::UserRole,data);
  22.  
  23. 		QString count = QString::number(rand()%100);
  24. 		item->setText(2,count );
  25. 		ui.treeWidget->addTopLevelItem(item);
  26. 	}
  27.  
  28.  
  29.  
  30. }
  31.  
  32. qttest::~qttest()
  33. {
  34.  
  35.  
  36. }
  37.  
  38.  
  39. void qttest::on_listWidget_currentRowChanged(int)
  40. {
  41.  
  42. }
  43.  
  44. void qttest::on_treeWidget_doubleClicked(QModelIndex)
  45. {
  46. 		//QString text = ui.treeWidget->currentItem()->text(1);
  47. 		char  *num =(char*)  ui.treeWidget->currentItem()->data(0,Qt::UserRole).value< char* >();
  48.  
  49.  
  50.  
  51. 		ui.listWidget->addItem(num);
  52. }
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Code can't compile ,here error

Qt Code: 
  1. Error	1	error C2039: 'qt_metatype_id' : is not a member of 'QMetaTypeId<T>'	e:\qt\4.2.2\src\corelib\kernel\qmetatype.h	166
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Thank you in advance.