XBEL stream example: use constructor initialization

The treeWidget member of MainWindow could be initialized before the
body of the constructor, enabling it to be a *const variable.

Task-number: QTBUG-111228
Change-Id: If4a3b04729bc7fa5859ca88183eec376f6992455
Reviewed-by: Ivan Solovev <ivan.solovev@qt.io>
(cherry picked from commit 5651be517a9f25798a051f7dd7548d40381148df)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

2 files changed, 2 insertions, 2 deletions

diff --git a/examples/corelib/serialization/streambookmarks/mainwindow.cpp b/examples/corelib/serialization/streambookmarks/mainwindow.cpp
index e84e8634b1..5a3cec6fb2 100644
--- a/examples/corelib/serialization/streambookmarks/mainwindow.cpp
+++ b/examples/corelib/serialization/streambookmarks/mainwindow.cpp
@@ -24,8 +24,8 @@ using namespace Qt::StringLiterals;
 
 //! [0]
 MainWindow::MainWindow()
+    : treeWidget(new QTreeWidget)
 {
-    treeWidget = new QTreeWidget;
     treeWidget->header()->setSectionResizeMode(QHeaderView::Stretch);
     treeWidget->setHeaderLabels(QStringList{ tr("Title"), tr("Location") });
 #if QT_CONFIG(clipboard) && QT_CONFIG(contextmenu)
diff --git a/examples/corelib/serialization/streambookmarks/mainwindow.h b/examples/corelib/serialization/streambookmarks/mainwindow.h
index 4f2a8901b0..d9efe6b5a5 100644
--- a/examples/corelib/serialization/streambookmarks/mainwindow.h
+++ b/examples/corelib/serialization/streambookmarks/mainwindow.h
@@ -28,7 +28,7 @@ public slots:
 private:
     void createMenus();
 
-    QTreeWidget *treeWidget;
+    QTreeWidget *const treeWidget;
 };
 //! [0]