More nullptr usage in headers

Diff generated by running clang-tidy's modernize-use-nullptr checker on
the CMake-based Qt version.

Skipping src/3rdparty, examples/, tests/

Change-Id: Ib182074e2e2fd52f63093f73b3e2e4c0cb7af188
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

3 files changed, 4 insertions, 4 deletions

diff --git a/src/widgets/util/qcompleter_p.h b/src/widgets/util/qcompleter_p.h
index 21dddf446e..a52e63a6e2 100644
--- a/src/widgets/util/qcompleter_p.h
+++ b/src/widgets/util/qcompleter_p.h
@@ -75,7 +75,7 @@ class QCompleterPrivate : public QObjectPrivate
 public:
     QCompleterPrivate();
     ~QCompleterPrivate() { delete popup; }
-    void init(QAbstractItemModel *model = 0);
+    void init(QAbstractItemModel *model = nullptr);
 
     QPointer<QWidget> widget;
     QCompletionModel *proxy;
diff --git a/src/widgets/util/qflickgesture_p.h b/src/widgets/util/qflickgesture_p.h
index d5ace887ae..0b47516047 100644
--- a/src/widgets/util/qflickgesture_p.h
+++ b/src/widgets/util/qflickgesture_p.h
@@ -71,7 +71,7 @@ class Q_WIDGETS_EXPORT QFlickGesture : public QGesture
     Q_DECLARE_PRIVATE(QFlickGesture)
 
 public:
-    QFlickGesture(QObject *receiver, Qt::MouseButton button, QObject *parent = 0);
+    QFlickGesture(QObject *receiver, Qt::MouseButton button, QObject *parent = nullptr);
     ~QFlickGesture();
 
     friend class QFlickGestureRecognizer;
diff --git a/src/widgets/util/qundostack_p.h b/src/widgets/util/qundostack_p.h
index 04bc381114..05c9e0d27e 100644
--- a/src/widgets/util/qundostack_p.h
+++ b/src/widgets/util/qundostack_p.h
@@ -80,7 +80,7 @@ class QUndoStackPrivate : public QObjectPrivate
 {
     Q_DECLARE_PUBLIC(QUndoStack)
 public:
-    QUndoStackPrivate() : index(0), clean_index(0), group(0), undo_limit(0) {}
+    QUndoStackPrivate() : index(0), clean_index(0), group(nullptr), undo_limit(0) {}
 
     QList<QUndoCommand*> command_list;
     QList<QUndoCommand*> macro_stack;
@@ -98,7 +98,7 @@ class QUndoAction : public QAction
 {
     Q_OBJECT
 public:
-    explicit QUndoAction(const QString &prefix, QObject *parent = 0);
+    explicit QUndoAction(const QString &prefix, QObject *parent = nullptr);
     void setTextFormat(const QString &textFormat, const QString &defaultText);
 public Q_SLOTS:
     void setPrefixedText(const QString &text);