Use nullptr here. Use QLatin1Char(...)

kcm/src/declarative/qmloutput.cpp

@@ -40,12 +40,12 @@ bool operator>(const QSize &sizeA, const QSize &sizeB)
 
 QMLOutput::QMLOutput(QQuickItem *parent):
     QQuickItem(parent),
-    m_screen(0),
-    m_cloneOf(0),
-    m_leftDock(0),
-    m_topDock(0),
-    m_rightDock(0),
-    m_bottomDock(0),
+    m_screen(nullptr),
+    m_cloneOf(nullptr),
+    m_leftDock(nullptr),
+    m_topDock(nullptr),
+    m_rightDock(nullptr),
+    m_bottomDock(nullptr),
     m_isCloneMode(false)
 {
     connect(this, &QMLOutput::xChanged,
@@ -91,7 +91,7 @@ QMLScreen *QMLOutput::screen() const
 
 void QMLOutput::setScreen(QMLScreen *screen)
 {
-    Q_ASSERT(m_screen == 0);
+    Q_ASSERT(m_screen == nullptr);
 
     m_screen = screen;
     Q_EMIT screenChanged();

kcm/src/declarative/qmlscreen.cpp

@@ -157,7 +157,7 @@ QMLOutput *QMLScreen::primaryOutput() const
         }
     }
 
-    return 0;
+    return nullptr;
 }
 
 QList<QMLOutput*> QMLScreen::outputs() const

kcm/src/scalingconfig.cpp

@@ -86,7 +86,7 @@ void ScalingConfig::accept()
 
     QString screenFactors;
     foreach (const KScreen::OutputPtr &output, m_outputList) {
-        screenFactors.append(output->name() + '=' + QString::number(scalingFactor) + ';');
+        screenFactors.append(output->name() + QLatin1Char('=') + QString::number(scalingFactor) + QLatin1Char(';'));
     }
     config->group("KScreen").writeEntry("ScreenScaleFactors", screenFactors);
 

kded/device.h

@@ -49,7 +49,7 @@ Q_SIGNALS:
     void aboutToSuspend();
 
 private:
-    explicit Device(QObject* parent = 0);
+    explicit Device(QObject* parent = nullptr);
     virtual ~Device();
 
     void setReady();