diff --git a/activation.cpp b/activation.cpp
index f1259fef78..a92cd36db3 100644
--- a/activation.cpp
+++ b/activation.cpp
@@ -875,8 +875,8 @@ void Client::setActive( bool act )
     StackingUpdatesBlocker blocker( workspace());
     workspace()->updateClientLayer( this ); // active windows may get different layer
     ClientList mainclients = mainClients();
-    for( ClientList::ConstIterator it = mainclients.begin();
-         it != mainclients.end();
+    for( ClientList::ConstIterator it = mainclients.constBegin();
+         it != mainclients.constEnd();
          ++it )
         if( (*it)->isFullScreen()) // fullscreens go high even if their transient is active
             workspace()->updateClientLayer( *it );
diff --git a/client.cpp b/client.cpp
index ef8b3fba20..a4c664adfe 100644
--- a/client.cpp
+++ b/client.cpp
@@ -645,8 +645,8 @@ bool Client::isMinimizable() const
         { // #66868 - let other xmms windows be minimized when the mainwindow is minimized
         bool shown_mainwindow = false;
         ClientList mainclients = mainClients();
-        for( ClientList::ConstIterator it = mainclients.begin();
-             it != mainclients.end();
+        for( ClientList::ConstIterator it = mainclients.constBegin();
+             it != mainclients.constEnd();
              ++it )
             {
             if( (*it)->isShown( true ))
@@ -857,8 +857,8 @@ void Client::updateVisibility()
         return;
         }
     bool belongs_to_desktop = false;
-    for( ClientList::ConstIterator it = group()->members().begin();
-         it != group()->members().end();
+    for( ClientList::ConstIterator it = group()->members().constBegin();
+         it != group()->members().constEnd();
          ++it )
         if( (*it)->isDesktop())
             {
@@ -1508,8 +1508,8 @@ void Client::getIcons()
     if( icon_pix.isNull() && isTransient())
         { // then mainclients
         ClientList mainclients = mainClients();
-        for( ClientList::ConstIterator it = mainclients.begin();
-             it != mainclients.end() && icon_pix.isNull();
+        for( ClientList::ConstIterator it = mainclients.constBegin();
+             it != mainclients.constEnd() && icon_pix.isNull();
              ++it )
             {
             icon_pix = (*it)->icon();
diff --git a/clients/plastik/config/config.cpp b/clients/plastik/config/config.cpp
index c1bf0a2b7b..dcde498d9b 100644
--- a/clients/plastik/config/config.cpp
+++ b/clients/plastik/config/config.cpp
@@ -90,7 +90,7 @@ void PlastikConfig::save(KConfigGroup&)
     KConfigGroup cg(m_config, "General");
 
     QList<QRadioButton *> buttons = m_dialog->titleAlign->findChildren<QRadioButton *>();
-    for(QList<QRadioButton *>::ConstIterator it = buttons.begin(); it != buttons.end(); ++it)
+    for(QList<QRadioButton *>::ConstIterator it = buttons.constBegin(); it != buttons.constEnd(); ++it)
     {
         if((*it)->isChecked())
             cg.writeEntry("TitleAlignment", QString((*it)->objectName()));
diff --git a/composite.cpp b/composite.cpp
index 34a56367df..d5c9558c0c 100644
--- a/composite.cpp
+++ b/composite.cpp
@@ -248,8 +248,8 @@ void Workspace::finishCompositing()
     scene = NULL;
     compositeTimer.stop();
     repaints_region = QRegion();
-    for( ClientList::ConstIterator it = clients.begin();
-         it != clients.end();
+    for( ClientList::ConstIterator it = clients.constBegin();
+         it != clients.constEnd();
          ++it )
         { // forward all opacity values to the frame in case there'll be other CM running
         if( (*it)->opacity() != 1.0 )
diff --git a/data/update_default_rules.cpp b/data/update_default_rules.cpp
index 9341050525..5997816f10 100644
--- a/data/update_default_rules.cpp
+++ b/data/update_default_rules.cpp
@@ -58,8 +58,8 @@ int main( int argc, char* argv[] )
         ++pos;
         dest_cfg.deleteGroup( QString::number( pos ));
 		KConfigGroup dcg2 (&dest_cfg, QString::number( pos ));
-        for( QMap< QString, QString >::ConstIterator it = entries.begin();
-             it != entries.end();
+        for( QMap< QString, QString >::ConstIterator it = entries.constBegin();
+             it != entries.constEnd();
              ++it )
             dcg2.writeEntry( it.key(), *it );
         }
diff --git a/geometry.cpp b/geometry.cpp
index fa828070d0..57f17ff4ce 100644
--- a/geometry.cpp
+++ b/geometry.cpp
@@ -108,7 +108,7 @@ void Workspace::updateClientArea( bool force )
              iS ++ )
             new_sareas[ i ][ iS ] = screens[ iS ];
         }
-    for ( ClientList::ConstIterator it = clients.begin(); it != clients.end(); ++it)
+    for ( ClientList::ConstIterator it = clients.constBegin(); it != clients.constEnd(); ++it)
         {
         if( !(*it)->hasStrut())
             continue;
@@ -200,12 +200,12 @@ void Workspace::updateClientArea( bool force )
             }
 
         updateTopMenuGeometry();
-        for( ClientList::ConstIterator it = clients.begin();
-             it != clients.end();
+        for( ClientList::ConstIterator it = clients.constBegin();
+             it != clients.constEnd();
              ++it)
             (*it)->checkWorkspacePosition();
-        for( ClientList::ConstIterator it = desktops.begin();
-             it != desktops.end();
+        for( ClientList::ConstIterator it = desktops.constBegin();
+             it != desktops.constEnd();
              ++it)
             (*it)->checkWorkspacePosition();
         }
@@ -353,7 +353,7 @@ QPoint Workspace::adjustClientPosition( Client* c, QPoint pos, bool unrestricted
         if (snap)
             {
             QList<Client *>::ConstIterator l;
-            for (l = clients.begin();l != clients.end();++l )
+            for (l = clients.constBegin();l != clients.constEnd();++l )
                 {
                 if ((*l)->isOnDesktop(currentDesktop()) &&
                    !(*l)->isMinimized()
@@ -568,7 +568,7 @@ QRect Workspace::adjustClientSize( Client* c, QRect moveResizeGeom, int mode )
             deltaX = int(snap);
             deltaY = int(snap);
             QList<Client *>::ConstIterator l;
-            for (l = clients.begin();l != clients.end();++l )
+            for (l = clients.constBegin();l != clients.constEnd();++l )
                 {
                 if ((*l)->isOnDesktop(currentDesktop()) &&
                    !(*l)->isMinimized()
@@ -790,8 +790,8 @@ void Workspace::updateTopMenuGeometry( Client* c )
     area = clientArea( MaximizeFullArea, QPoint( 0, 0 ), 1 ); // HACK desktop ?
     area.setHeight( topMenuHeight());
     topmenu_space->setGeometry( area );
-    for( ClientList::ConstIterator it = topmenus.begin();
-         it != topmenus.end();
+    for( ClientList::ConstIterator it = topmenus.constBegin();
+         it != topmenus.constEnd();
          ++it )
         updateTopMenuGeometry( *it );
     }
diff --git a/group.cpp b/group.cpp
index 51d634e6c6..e7cf5628c9 100644
--- a/group.cpp
+++ b/group.cpp
@@ -65,8 +65,8 @@ bool performTransiencyCheck()
     {
     bool ret = true;
     ClientList clients = Workspace::self()->clients;
-    for( ClientList::ConstIterator it1 = clients.begin();
-         it1 != clients.end();
+    for( ClientList::ConstIterator it1 = clients.constBegin();
+         it1 != clients.constEnd();
          ++it1 )
         {
         if( (*it1)->deleting )
@@ -92,8 +92,8 @@ bool performTransiencyCheck()
         else
             {
             ClientList mains = (*it1)->mainClients();
-            for( ClientList::ConstIterator it2 = mains.begin();
-                 it2 != mains.end();
+            for( ClientList::ConstIterator it2 = mains.constBegin();
+                 it2 != mains.constEnd();
                  ++it2 )
                 {
                 if( transiencyCheckNonExistent
@@ -113,8 +113,8 @@ bool performTransiencyCheck()
                 }
             }
         ClientList trans = (*it1)->transients_list;
-        for( ClientList::ConstIterator it2 = trans.begin();
-             it2 != trans.end();
+        for( ClientList::ConstIterator it2 = trans.constBegin();
+             it2 != trans.constEnd();
              ++it2 )
             {
             if( transiencyCheckNonExistent
@@ -134,13 +134,13 @@ bool performTransiencyCheck()
             }
         }
     GroupList groups = Workspace::self()->groups;
-    for( GroupList::ConstIterator it1 = groups.begin();
-         it1 != groups.end();
+    for( GroupList::ConstIterator it1 = groups.constBegin();
+         it1 != groups.constEnd();
          ++it1 )
         {
         ClientList members = (*it1)->members();
-        for( ClientList::ConstIterator it2 = members.begin();
-             it2 != members.end();
+        for( ClientList::ConstIterator it2 = members.constBegin();
+             it2 != members.constEnd();
              ++it2 )
             {
             if( (*it2)->in_group != *it1 )
@@ -329,8 +329,8 @@ void Group::getIcons()
 Group* Workspace::findGroup( Window leader ) const
     {
     assert( leader != None );
-    for( GroupList::ConstIterator it = groups.begin();
-         it != groups.end();
+    for( GroupList::ConstIterator it = groups.constBegin();
+         it != groups.constEnd();
          ++it )
         if( (*it)->leader() == leader )
             return *it;
@@ -343,8 +343,8 @@ Group* Workspace::findClientLeaderGroup( const Client* c ) const
     {
     TRANSIENCY_CHECK( c );
     Group* ret = NULL;
-    for( ClientList::ConstIterator it = clients.begin();
-         it != clients.end();
+    for( ClientList::ConstIterator it = clients.constBegin();
+         it != clients.constEnd();
          ++it )
         {
         if( *it == c )
@@ -380,8 +380,8 @@ void Workspace::updateMinimizedOfTransients( Client* c )
     // if mainwindow is minimized or shaded, minimize transients too
     if ( c->isMinimized() || c->isShade() )
         {
-        for( ClientList::ConstIterator it = c->transients().begin();
-             it != c->transients().end();
+        for( ClientList::ConstIterator it = c->transients().constBegin();
+             it != c->transients().constEnd();
              ++it )
             {
             if( !(*it)->isMinimized()
@@ -394,8 +394,8 @@ void Workspace::updateMinimizedOfTransients( Client* c )
         }
     else
         { // else unmiminize the transients
-        for( ClientList::ConstIterator it = c->transients().begin();
-             it != c->transients().end();
+        for( ClientList::ConstIterator it = c->transients().constBegin();
+             it != c->transients().constEnd();
              ++it )
             {
             if( (*it)->isMinimized()
@@ -414,8 +414,8 @@ void Workspace::updateMinimizedOfTransients( Client* c )
  */
 void Workspace::updateOnAllDesktopsOfTransients( Client* c )
     {
-    for( ClientList::ConstIterator it = c->transients().begin();
-         it != c->transients().end();
+    for( ClientList::ConstIterator it = c->transients().constBegin();
+         it != c->transients().constEnd();
          ++it)
         {
         if( (*it)->isOnAllDesktops() != c->isOnAllDesktops())
@@ -427,8 +427,8 @@ void Workspace::updateOnAllDesktopsOfTransients( Client* c )
 void Workspace::checkTransients( Window w )
     {
     TRANSIENCY_CHECK( NULL );
-    for( ClientList::ConstIterator it = clients.begin();
-         it != clients.end();
+    for( ClientList::ConstIterator it = clients.constBegin();
+         it != clients.constEnd();
          ++it )
         (*it)->checkTransient( w );
     }
@@ -639,8 +639,8 @@ void Client::removeFromMainClients()
         transientFor()->removeTransient( this );
     if( groupTransient())
         {
-        for( ClientList::ConstIterator it = group()->members().begin();
-             it != group()->members().end();
+        for( ClientList::ConstIterator it = group()->members().constBegin();
+             it != group()->members().constEnd();
              ++it )
             (*it)->removeTransient( this );
         }
@@ -675,14 +675,14 @@ void Client::cleanGrouping()
 //         it != mains.end();
 //         ++it )
 //        kDebug() << "MN2:" << *it;
-    for( ClientList::ConstIterator it = transients_list.begin();
-         it != transients_list.end();
+    for( ClientList::ConstIterator it = transients_list.constBegin();
+         it != transients_list.constEnd();
          )
         {
         if( (*it)->transientFor() == this )
             {
             removeTransient( *it );
-            it = transients_list.begin(); // restart, just in case something more has changed with the list
+            it = transients_list.constBegin(); // restart, just in case something more has changed with the list
             }
         else
             ++it;
@@ -705,8 +705,8 @@ void Client::cleanGrouping()
     ClientList group_members = group()->members();
     group()->removeMember( this );
     in_group = NULL;
-    for( ClientList::ConstIterator it = group_members.begin();
-         it != group_members.end();
+    for( ClientList::ConstIterator it = group_members.constBegin();
+         it != group_members.constEnd();
          ++it )
         (*it)->removeTransient( this );
 //    kDebug() << "CLEANGROUPING4:" << this;
@@ -723,14 +723,14 @@ void Client::cleanGrouping()
 void Client::checkGroupTransients()
     {
     TRANSIENCY_CHECK( this );
-    for( ClientList::ConstIterator it1 = group()->members().begin();
-         it1 != group()->members().end();
+    for( ClientList::ConstIterator it1 = group()->members().constBegin();
+         it1 != group()->members().constEnd();
          ++it1 )
         {
         if( !(*it1)->groupTransient()) // check all group transients in the group
             continue;                  // TODO optimize to check only the changed ones?
-        for( ClientList::ConstIterator it2 = group()->members().begin();
-             it2 != group()->members().end();
+        for( ClientList::ConstIterator it2 = group()->members().constBegin();
+             it2 != group()->members().constEnd();
              ++it2 ) // group transients can be transient only for others in the group,
             {        // so don't make them transient for the ones that are transient for it
             if( *it1 == *it2 )
@@ -756,8 +756,8 @@ void Client::checkGroupTransients()
             // transient for it - the indirect transiency actually shouldn't break anything,
             // but it can lead to exponentially expensive operations (#95231)
             // TODO this is pretty slow as well
-            for( ClientList::ConstIterator it3 = group()->members().begin();
-                 it3 != group()->members().end();
+            for( ClientList::ConstIterator it3 = group()->members().constBegin();
+                 it3 != group()->members().constEnd();
                  ++it3 )
                 {
                 if( *it1 == *it2 || *it2 == *it3 || *it1 == *it3 )
@@ -928,8 +928,8 @@ bool Client::hasTransientInternal( const Client* cl, bool indirect, ConstClientL
     if( set.contains( this ))
         return false;
     set.append( this );
-    for( ClientList::ConstIterator it = transients().begin();
-         it != transients().end();
+    for( ClientList::ConstIterator it = transients().constBegin();
+         it != transients().constEnd();
          ++it )
         if( (*it)->hasTransientInternal( cl, indirect, set ))
             return true;
@@ -943,8 +943,8 @@ ClientList Client::mainClients() const
     if( transientFor() != NULL )
         return ClientList() << const_cast< Client* >( transientFor());
     ClientList result;
-    for( ClientList::ConstIterator it = group()->members().begin();
-         it != group()->members().end();
+    for( ClientList::ConstIterator it = group()->members().constBegin();
+         it != group()->members().constEnd();
          ++it )
         if((*it)->hasTransient( this, false ))
             result.append( *it );
@@ -961,8 +961,8 @@ ClientList Client::allMainClients() const
 
 Client* Client::findModal( bool allow_itself )
     {
-    for( ClientList::ConstIterator it = transients().begin();
-         it != transients().end();
+    for( ClientList::ConstIterator it = transients().constBegin();
+         it != transients().constEnd();
          ++it )
         if( Client* ret = (*it)->findModal( true ))
             return ret;
@@ -1071,14 +1071,14 @@ void Client::checkGroup( Group* set_group, bool force )
             // no longer transient for ones in the old group
             if( old_group != NULL )
                 {
-                for( ClientList::ConstIterator it = old_group->members().begin();
-                     it != old_group->members().end();
+                for( ClientList::ConstIterator it = old_group->members().constBegin();
+                     it != old_group->members().constEnd();
                      ++it )
                     (*it)->removeTransient( this );
                 }
             // and make transient for all in the new group
-            for( ClientList::ConstIterator it = group()->members().begin();
-                 it != group()->members().end();
+            for( ClientList::ConstIterator it = group()->members().constBegin();
+                 it != group()->members().constEnd();
                  ++it )
                 {
                 if( *it == this )
@@ -1088,8 +1088,8 @@ void Client::checkGroup( Group* set_group, bool force )
             }
         // group transient splashscreens should be transient even for windows
         // in group mapped later
-        for( ClientList::ConstIterator it = group()->members().begin();
-             it != group()->members().end();
+        for( ClientList::ConstIterator it = group()->members().constBegin();
+             it != group()->members().constEnd();
              ++it )
             {
             if( !(*it)->isSplash())
diff --git a/kcmkwin/kwindecoration/buttons.cpp b/kcmkwin/kwindecoration/buttons.cpp
index f09067f90d..2ace9ae2d6 100644
--- a/kcmkwin/kwindecoration/buttons.cpp
+++ b/kcmkwin/kwindecoration/buttons.cpp
@@ -516,7 +516,7 @@ void ButtonDropSite::recalcItemGeometry()
 
 	// update the geometry of the items in the left button list
 	int offset = r.left();
-	for (ButtonList::const_iterator it = buttonsLeft.begin(); it != buttonsLeft.end(); ++it) {
+	for (ButtonList::const_iterator it = buttonsLeft.constBegin(); it != buttonsLeft.constEnd(); ++it) {
 		int w = (*it)->width();
 		(*it)->rect = QRect(offset, r.top(), w, (*it)->height() );
 		offset += w;
@@ -524,7 +524,7 @@ void ButtonDropSite::recalcItemGeometry()
 
 	// the right button list...
 	offset = r.right() - calcButtonListWidth(buttonsRight);
-	for (ButtonList::const_iterator it = buttonsRight.begin(); it != buttonsRight.end(); ++it) {
+	for (ButtonList::const_iterator it = buttonsRight.constBegin(); it != buttonsRight.constEnd(); ++it) {
 		int w = (*it)->width();
 		(*it)->rect = QRect(offset, r.top(), w, (*it)->height() );
 		offset += w;
@@ -533,14 +533,14 @@ void ButtonDropSite::recalcItemGeometry()
 
 ButtonDropSiteItem *ButtonDropSite::buttonAt(QPoint p) {
 	// try to find the item in the left button list
-	for (ButtonList::const_iterator it = buttonsLeft.begin(); it != buttonsLeft.end(); ++it) {
+	for (ButtonList::const_iterator it = buttonsLeft.constBegin(); it != buttonsLeft.constEnd(); ++it) {
 		if ( (*it)->rect.contains(p) ) {
 			return *it;
 		}
 	}
 
 	// try to find the item in the right button list
-	for (ButtonList::const_iterator it = buttonsRight.begin(); it != buttonsRight.end(); ++it) {
+	for (ButtonList::const_iterator it = buttonsRight.constBegin(); it != buttonsRight.constEnd(); ++it) {
 		if ( (*it)->rect.contains(p) ) {
 			return *it;
 		}
@@ -569,7 +569,7 @@ bool ButtonDropSite::removeButton(ButtonDropSiteItem *item) {
 int ButtonDropSite::calcButtonListWidth(const ButtonList& btns)
 {
 	int w = 0;
-	for (ButtonList::const_iterator it = btns.begin(); it != btns.end(); ++it) {
+	for (ButtonList::const_iterator it = btns.constBegin(); it != btns.constEnd(); ++it) {
 		w += (*it)->width();
 	}
 
@@ -593,7 +593,7 @@ bool ButtonDropSite::removeSelectedButton()
 
 void ButtonDropSite::drawButtonList(QPainter *p, const ButtonList& btns, int offset)
 {
-	for (ButtonList::const_iterator it = btns.begin(); it != btns.end(); ++it) {
+	for (ButtonList::const_iterator it = btns.constBegin(); it != btns.constEnd(); ++it) {
 		QRect itemRect = (*it)->rect;
 		if (itemRect.isValid() ) {
 			(*it)->draw(p, palette(), itemRect);
@@ -847,7 +847,7 @@ QString ButtonPositionWidget::buttonsLeft() const
 {
 	ButtonList btns = m_dropSite->buttonsLeft;
 	QString btnString = "";
-	for (ButtonList::const_iterator it = btns.begin(); it != btns.end(); ++it) {
+	for (ButtonList::const_iterator it = btns.constBegin(); it != btns.constEnd(); ++it) {
 		btnString.append( (*it)->button().type );
 	}
 	return btnString;
@@ -857,7 +857,7 @@ QString ButtonPositionWidget::buttonsRight() const
 {
 	ButtonList btns = m_dropSite->buttonsRight;
 	QString btnString = "";
-	for (ButtonList::const_iterator it = btns.begin(); it != btns.end(); ++it) {
+	for (ButtonList::const_iterator it = btns.constBegin(); it != btns.constEnd(); ++it) {
 		btnString.append( (*it)->button().type );
 	}
 	return btnString;
diff --git a/kcmkwin/kwindecoration/kwindecoration.cpp b/kcmkwin/kwindecoration/kwindecoration.cpp
index ebe79bfc92..8337b4bde6 100644
--- a/kcmkwin/kwindecoration/kwindecoration.cpp
+++ b/kcmkwin/kwindecoration/kwindecoration.cpp
@@ -217,10 +217,10 @@ KWinDecorationModule::~KWinDecorationModule()
 // And insert these into a DecorationInfo structure
 void KWinDecorationModule::findDecorations()
 {
-	QStringList dirList = KGlobal::dirs()->findDirs("data", "kwin");
+	const QStringList dirList = KGlobal::dirs()->findDirs("data", "kwin");
 	QStringList::ConstIterator it;
 
-	for (it = dirList.begin(); it != dirList.end(); ++it)
+	for (it = dirList.constBegin(); it != dirList.constEnd(); ++it)
 	{
 		QDir d(*it);
 		if (d.exists())
@@ -253,7 +253,7 @@ void KWinDecorationModule::createDecorationList()
 	// Sync with kwin hardcoded KDE2 style which has no desktop item
     QStringList decorationNames;
 //	decorationNames.append( i18n("KDE 2") );
-	for (it = decorations.begin(); it != decorations.end(); ++it)
+	for (it = decorations.constBegin(); it != decorations.constEnd(); ++it)
 	{
 		decorationNames.append((*it).name);
 	}
@@ -293,8 +293,8 @@ static const char* const border_names[ KDecorationDefines::BordersCount ] =
 int KWinDecorationModule::borderSizeToIndex( BorderSize size, QList< BorderSize > sizes )
 {
         int pos = 0;
-        for( QList< BorderSize >::ConstIterator it = sizes.begin();
-             it != sizes.end();
+        for( QList< BorderSize >::ConstIterator it = sizes.constBegin();
+             it != sizes.constEnd();
              ++it, ++pos )
             if( size <= *it )
                 break;
@@ -304,9 +304,9 @@ int KWinDecorationModule::borderSizeToIndex( BorderSize size, QList< BorderSize
 KDecorationDefines::BorderSize KWinDecorationModule::indexToBorderSize( int index,
     QList< BorderSize > sizes )
 {
-        QList< BorderSize >::ConstIterator it = sizes.begin();
+        QList< BorderSize >::ConstIterator it = sizes.constBegin();
         for(;
-             it != sizes.end();
+             it != sizes.constEnd();
              ++it, --index )
             if( index == 0 )
                 break;
@@ -576,7 +576,7 @@ void KWinDecorationModule::checkSupportedBorderSizes()
 		cBorder->hide();
 	} else {
 		cBorder->clear();
-		for (QList<BorderSize>::const_iterator it = sizes.begin(); it != sizes.end(); ++it) {
+		for (QList<BorderSize>::const_iterator it = sizes.constBegin(); it != sizes.constEnd(); ++it) {
 			BorderSize size = *it;
 			cBorder->addItem(i18n(border_names[size]), borderSizeToIndex(size,sizes) );
 		}
diff --git a/kcmkwin/kwinrules/main.cpp b/kcmkwin/kwinrules/main.cpp
index 24c3833ad2..31e60b4175 100644
--- a/kcmkwin/kwinrules/main.cpp
+++ b/kcmkwin/kwinrules/main.cpp
@@ -51,14 +51,14 @@ static void saveRules( const QList< Rules* >& rules )
     {
     KConfig cfg( "kwinrulesrc" );
     QStringList groups = cfg.groupList();
-    for( QStringList::ConstIterator it = groups.begin();
-         it != groups.end();
+    for( QStringList::ConstIterator it = groups.constBegin();
+         it != groups.constEnd();
          ++it )
         cfg.deleteGroup( *it );
     cfg.group("General").writeEntry( "count", rules.count());
     int i = 1;
-    for( QList< Rules* >::ConstIterator it = rules.begin();
-         it != rules.end();
+    for( QList< Rules* >::ConstIterator it = rules.constBegin();
+         it != rules.constEnd();
          ++it )
         {
             KConfigGroup cg( &cfg, QString::number( i ));
@@ -85,8 +85,8 @@ static Rules* findRule( const QList< Rules* >& rules, Window wid, bool whole_app
     QByteArray machine = info.clientMachine().toLower();
     Rules* best_match = NULL;
     int match_quality = 0;
-    for( QList< Rules* >::ConstIterator it = rules.begin();
-         it != rules.end();
+    for( QList< Rules* >::ConstIterator it = rules.constBegin();
+         it != rules.constEnd();
          ++it )
         {
         // try to find an exact match, i.e. not a generic rule
diff --git a/kcmkwin/kwinrules/ruleslist.cpp b/kcmkwin/kwinrules/ruleslist.cpp
index 8156e47318..028ad185f7 100644
--- a/kcmkwin/kwinrules/ruleslist.cpp
+++ b/kcmkwin/kwinrules/ruleslist.cpp
@@ -178,14 +178,14 @@ void KCMRulesList::save()
     {
     KConfig cfg( QLatin1String("kwinrulesrc") );
     QStringList groups = cfg.groupList();
-    for( QStringList::ConstIterator it = groups.begin();
-         it != groups.end();
+    for( QStringList::ConstIterator it = groups.constBegin();
+         it != groups.constEnd();
          ++it )
         cfg.deleteGroup( *it );
     cfg.group("General").writeEntry( "count", rules.count());
     int i = 1;
-    for( QVector< Rules* >::ConstIterator it = rules.begin();
-         it != rules.end();
+    for( QVector< Rules* >::ConstIterator it = rules.constBegin();
+         it != rules.constEnd();
          ++it )
         {
             KConfigGroup cg( &cfg, QString::number( i ));
diff --git a/layers.cpp b/layers.cpp
index ad02fbff67..31aaa40e7c 100644
--- a/layers.cpp
+++ b/layers.cpp
@@ -101,8 +101,8 @@ void Workspace::updateClientLayer( Client* c )
         return;
     StackingUpdatesBlocker blocker( this );
     c->invalidateLayer(); // invalidate, will be updated when doing restacking
-    for( ClientList::ConstIterator it = c->transients().begin();
-         it != c->transients().end();
+    for( ClientList::ConstIterator it = c->transients().constBegin();
+         it != c->transients().constEnd();
          ++it )
         updateClientLayer( *it );
     }
@@ -202,9 +202,9 @@ void Workspace::propagateClients( bool propagate_new_clients )
         cl = new Window[ desktops.count() + clients.count()];
         pos = 0;
 	// TODO this is still not completely in the map order
-        for ( ClientList::ConstIterator it = desktops.begin(); it != desktops.end(); ++it )
+        for ( ClientList::ConstIterator it = desktops.constBegin(); it != desktops.constEnd(); ++it )
             cl[pos++] =  (*it)->window();
-        for ( ClientList::ConstIterator it = clients.begin(); it != clients.end(); ++it )
+        for ( ClientList::ConstIterator it = clients.constBegin(); it != clients.constEnd(); ++it )
             cl[pos++] =  (*it)->window();
         rootInfo->setClientList( cl, pos );
         delete [] cl;
@@ -212,7 +212,7 @@ void Workspace::propagateClients( bool propagate_new_clients )
 
     cl = new Window[ stacking_order.count()];
     pos = 0;
-    for ( ClientList::ConstIterator it = stacking_order.begin(); it != stacking_order.end(); ++it)
+    for ( ClientList::ConstIterator it = stacking_order.constBegin(); it != stacking_order.constEnd(); ++it)
         cl[pos++] =  (*it)->window();
     rootInfo->setClientListStacking( cl, pos );
     delete [] cl;
@@ -571,8 +571,8 @@ ClientList Workspace::constrainedStackingOrder()
 #endif
     // build the order from layers
     QHash< Group*, Layer > minimum_layer;
-    for( ClientList::ConstIterator it = unconstrained_stacking_order.begin();
-         it != unconstrained_stacking_order.end();
+    for( ClientList::ConstIterator it = unconstrained_stacking_order.constBegin();
+         it != unconstrained_stacking_order.constEnd();
          ++it )
         {
         Layer l = (*it)->layer();
@@ -693,8 +693,8 @@ ClientList Workspace::ensureStackingOrder( const ClientList& list ) const
         return list;
     // TODO is this worth optimizing?
     ClientList result = list;
-    for( ClientList::ConstIterator it = stacking_order.begin();
-         it != stacking_order.end();
+    for( ClientList::ConstIterator it = stacking_order.constBegin();
+         it != stacking_order.constEnd();
          ++it )
         if( result.removeAll( *it ) != 0 )
             result.append( *it );
diff --git a/lib/kdecoration_p.cpp b/lib/kdecoration_p.cpp
index e36180221a..964d0dbf1e 100644
--- a/lib/kdecoration_p.cpp
+++ b/lib/kdecoration_p.cpp
@@ -223,8 +223,8 @@ unsigned long KDecorationOptionsPrivate::updateSettings( KConfig* config )
 KDecorationDefines::BorderSize KDecorationOptionsPrivate::findPreferredBorderSize( BorderSize size,
     QList< BorderSize > sizes ) const
     {
-    for( QList< BorderSize >::ConstIterator it = sizes.begin();
-         it != sizes.end();
+    for( QList< BorderSize >::ConstIterator it = sizes.constBegin();
+         it != sizes.constEnd();
          ++it )
         if( size <= *it ) // size is either a supported size, or *it is the closest larger supported
             return *it;
diff --git a/lib/kdecorationfactory.cpp b/lib/kdecorationfactory.cpp
index a5314b98c8..90de5b233e 100644
--- a/lib/kdecorationfactory.cpp
+++ b/lib/kdecorationfactory.cpp
@@ -68,8 +68,8 @@ void KDecorationFactory::removeDecoration( KDecoration* deco )
 
 void KDecorationFactory::resetDecorations( unsigned long changed )
     {
-    for( QList< KDecoration* >::ConstIterator it = _decorations.begin();
-         it != _decorations.end();
+    for( QList< KDecoration* >::ConstIterator it = _decorations.constBegin();
+         it != _decorations.constEnd();
          ++it )
         (*it)->reset( changed );
     }
diff --git a/manage.cpp b/manage.cpp
index 76cc179043..832fc4fd44 100644
--- a/manage.cpp
+++ b/manage.cpp
@@ -169,8 +169,8 @@ bool Client::manage( Window w, bool isMapped )
             bool on_current = false;
             Client* maincl = NULL;
             // this is slightly duplicated from Placement::placeOnMainWindow()
-            for( ClientList::ConstIterator it = mainclients.begin();
-                 it != mainclients.end();
+            for( ClientList::ConstIterator it = mainclients.constBegin();
+                 it != mainclients.constEnd();
                  ++it )
                 {
                 if( mainclients.count() > 1 && (*it)->isSpecialWindow())
@@ -338,8 +338,8 @@ bool Client::manage( Window w, bool isMapped )
     if( init_minimize && isTransient())
         {
         ClientList mainclients = mainClients();
-        for( ClientList::ConstIterator it = mainclients.begin();
-             it != mainclients.end();
+        for( ClientList::ConstIterator it = mainclients.constBegin();
+             it != mainclients.constEnd();
              ++it )
             if( (*it)->isShown( true ))
                 init_minimize = false; // SELI even e.g. for NET::Utility?
@@ -351,8 +351,8 @@ bool Client::manage( Window w, bool isMapped )
         // use allMainClients(), to include also main clients of group transients
         // that have been optimized out in Client::checkGroupTransients()
         ClientList mainclients = allMainClients();
-        for( ClientList::ConstIterator it = mainclients.begin();
-             it != mainclients.end();
+        for( ClientList::ConstIterator it = mainclients.constBegin();
+             it != mainclients.constEnd();
              ++it )
             if( (*it)->isShown( true ))
                 visible_parent = true;
@@ -492,8 +492,8 @@ bool Client::manage( Window w, bool isMapped )
             workspace()->setCurrentDesktop( desktop());
 
         bool belongs_to_desktop = false;
-        for( ClientList::ConstIterator it = group()->members().begin();
-             it != group()->members().end();
+        for( ClientList::ConstIterator it = group()->members().constBegin();
+             it != group()->members().constEnd();
              ++it )
             if( (*it)->isDesktop())
                 {
diff --git a/placement.cpp b/placement.cpp
index a947c587a9..d44924dc41 100644
--- a/placement.cpp
+++ b/placement.cpp
@@ -187,7 +187,7 @@ void Placement::placeSmart(Client* c, const QRect& area, Policy /*next*/ )
             cxl = x; cxr = x + cw;
             cyt = y; cyb = y + ch;
             ClientList::ConstIterator l;
-            for(l = m_WorkspacePtr->stackingOrder().begin(); l != m_WorkspacePtr->stackingOrder().end() ; ++l) 
+            for(l = m_WorkspacePtr->stackingOrder().constBegin(); l != m_WorkspacePtr->stackingOrder().constEnd() ; ++l) 
                 {
                 if((*l)->isOnDesktop(desktop) &&
                    (*l)->isShown( false ) && (*l) != c) 
@@ -243,7 +243,7 @@ void Placement::placeSmart(Client* c, const QRect& area, Policy /*next*/ )
 
             // compare to the position of each client on the same desk
             ClientList::ConstIterator l;
-            for(l = m_WorkspacePtr->stackingOrder().begin(); l != m_WorkspacePtr->stackingOrder().end() ; ++l) 
+            for(l = m_WorkspacePtr->stackingOrder().constBegin(); l != m_WorkspacePtr->stackingOrder().constEnd() ; ++l) 
                 {
 
                 if ((*l)->isOnDesktop(desktop) &&
@@ -278,7 +278,7 @@ void Placement::placeSmart(Client* c, const QRect& area, Policy /*next*/ )
 
             //test the position of each window on the desk
             ClientList::ConstIterator l;
-            for(l = m_WorkspacePtr->stackingOrder().begin(); l != m_WorkspacePtr->stackingOrder().end() ; ++l) 
+            for(l = m_WorkspacePtr->stackingOrder().constBegin(); l != m_WorkspacePtr->stackingOrder().constEnd() ; ++l) 
                 {
                 if((*l)->isOnDesktop(desktop) &&
                     (*l) != c   &&  c->isShown( false )) 
@@ -481,8 +481,8 @@ void Placement::placeOnMainWindow(Client* c, QRect& area, Policy nextPlacement )
     Client* place_on = NULL;
     Client* place_on2 = NULL;
     int mains_count = 0;
-    for( ClientList::ConstIterator it = mainwindows.begin();
-         it != mainwindows.end();
+    for( ClientList::ConstIterator it = mainwindows.constBegin();
+         it != mainwindows.constEnd();
          ++it )
         {
         if( mainwindows.count() > 1 && (*it)->isSpecialWindow())
@@ -727,8 +727,8 @@ int Workspace::packPositionLeft( const Client* cl, int oldx, bool left_edge ) co
             QPoint( cl->geometry().left() - 1, cl->geometry().center().y()), cl->desktop()).left();
     if( oldx <= newx )
         return oldx;
-    for( ClientList::ConstIterator it = clients.begin();
-         it != clients.end();
+    for( ClientList::ConstIterator it = clients.constBegin();
+         it != clients.constEnd();
          ++it)
         {
         if( !(*it)->isShown( false ) || !(*it)->isOnDesktop( active_client->desktop()))
@@ -750,8 +750,8 @@ int Workspace::packPositionRight( const Client* cl, int oldx, bool right_edge )
             QPoint( cl->geometry().right() + 1, cl->geometry().center().y()), cl->desktop()).right();
     if( oldx >= newx )
         return oldx;
-    for( ClientList::ConstIterator it = clients.begin();
-         it != clients.end();
+    for( ClientList::ConstIterator it = clients.constBegin();
+         it != clients.constEnd();
          ++it)
         {
         if( !(*it)->isShown( false ) || !(*it)->isOnDesktop( cl->desktop()))
@@ -773,8 +773,8 @@ int Workspace::packPositionUp( const Client* cl, int oldy, bool top_edge ) const
             QPoint( cl->geometry().center().x(), cl->geometry().top() - 1 ), cl->desktop()).top();
     if( oldy <= newy )
         return oldy;
-    for( ClientList::ConstIterator it = clients.begin();
-         it != clients.end();
+    for( ClientList::ConstIterator it = clients.constBegin();
+         it != clients.constEnd();
          ++it)
         {
         if( !(*it)->isShown( false ) || !(*it)->isOnDesktop( cl->desktop()))
@@ -796,8 +796,8 @@ int Workspace::packPositionDown( const Client* cl, int oldy, bool bottom_edge )
             QPoint( cl->geometry().center().x(), cl->geometry().bottom() + 1 ), cl->desktop()).bottom();
     if( oldy >= newy )
         return oldy;
-    for( ClientList::ConstIterator it = clients.begin();
-         it != clients.end();
+    for( ClientList::ConstIterator it = clients.constBegin();
+         it != clients.constEnd();
          ++it)
         {
         if( !(*it)->isShown( false ) || !(*it)->isOnDesktop( cl->desktop()))
diff --git a/rules.cpp b/rules.cpp
index bf4bdfba90..d34ec8eec5 100644
--- a/rules.cpp
+++ b/rules.cpp
@@ -709,8 +709,8 @@ void WindowRules::discardTemporary()
 void WindowRules::update( Client* c )
     {
     bool updated = false;
-    for( QVector< Rules* >::ConstIterator it = rules.begin();
-         it != rules.end();
+    for( QVector< Rules* >::ConstIterator it = rules.constBegin();
+         it != rules.constEnd();
          ++it )
         if( (*it)->update( c )) // no short-circuiting here
             updated = true;
@@ -724,8 +724,8 @@ type WindowRules::check##rule( type arg, bool init ) const \
     if( rules.count() == 0 ) \
         return arg; \
     type ret = arg; \
-    for( QVector< Rules* >::ConstIterator it = rules.begin(); \
-         it != rules.end(); \
+    for( QVector< Rules* >::ConstIterator it = rules.constBegin(); \
+         it != rules.constEnd(); \
          ++it ) \
         { \
         if( (*it)->apply##rule( ret, init )) \
@@ -935,14 +935,14 @@ void Workspace::writeWindowRules()
     rulesUpdatedTimer.stop();
     KConfig cfg( "kwinrulesrc", KConfig::NoGlobals );
     QStringList groups = cfg.groupList();
-    for( QStringList::ConstIterator it = groups.begin();
-         it != groups.end();
+    for( QStringList::ConstIterator it = groups.constBegin();
+         it != groups.constEnd();
          ++it )
         cfg.deleteGroup( *it );
     cfg.group("General").writeEntry( "count", rules.count());
     int i = 1;
-    for( QList< Rules* >::ConstIterator it = rules.begin();
-         it != rules.end();
+    for( QList< Rules* >::ConstIterator it = rules.constBegin();
+         it != rules.constEnd();
          ++it )
         {
         if( (*it)->isTemporary())
@@ -956,8 +956,8 @@ void Workspace::writeWindowRules()
 void Workspace::gotTemporaryRulesMessage( const QString& message )
     {
     bool was_temporary = false;
-    for( QList< Rules* >::ConstIterator it = rules.begin();
-         it != rules.end();
+    for( QList< Rules* >::ConstIterator it = rules.constBegin();
+         it != rules.constEnd();
          ++it )
         if( (*it)->isTemporary())
             was_temporary = true;
diff --git a/scene_basic.cpp b/scene_basic.cpp
index 32ba2d6f32..0513a8ddb8 100644
--- a/scene_basic.cpp
+++ b/scene_basic.cpp
@@ -50,8 +50,8 @@ void SceneBasic::paint( QRegion, ToplevelList windows )
     val.subwindow_mode = IncludeInferiors;
     GC gc = XCreateGC( display(), composite_pixmap, GCForeground | GCSubwindowMode, &val );
     XFillRectangle( display(), composite_pixmap, gc, 0, 0, displayWidth(), displayHeight());
-    for( ToplevelList::ConstIterator it = windows.begin();
-         it != windows.end();
+    for( ToplevelList::ConstIterator it = windows.constBegin();
+         it != windows.constEnd();
          ++it )
         {
         QRect r = (*it)->geometry().intersected( QRect( 0, 0, displayWidth(), displayHeight()));
diff --git a/tabbox.cpp b/tabbox.cpp
index da66143c97..5d1a1739a5 100644
--- a/tabbox.cpp
+++ b/tabbox.cpp
@@ -208,7 +208,7 @@ void TabBox::reset( bool partial_reset )
 
         // calculate maximum caption width
         cw = fontMetrics().width(no_tasks)+20;
-        for (ClientList::ConstIterator it = clients.begin(); it != clients.end(); ++it)
+        for (ClientList::ConstIterator it = clients.constBegin(); it != clients.constEnd(); ++it)
           {
           cw = fontMetrics().width( (*it)->caption() );
           if ( cw > wmax ) wmax = cw;
@@ -460,7 +460,7 @@ void TabBox::paintEvent( QPaintEvent* e )
             }
         else
             {
-            for (ClientList::ConstIterator it = clients.begin(); it != clients.end(); ++it)
+            for (ClientList::ConstIterator it = clients.constBegin(); it != clients.constEnd(); ++it)
               {
               if ( workspace()->hasClient( *it ) )  // safety
                   {
@@ -719,8 +719,8 @@ void TabBox::handleMouseEvent( XEvent* e )
 
     if( mode() == TabBoxWindowsMode )
         {
-        for( ClientList::ConstIterator it = clients.begin();
-             it != clients.end();
+        for( ClientList::ConstIterator it = clients.constBegin();
+             it != clients.constEnd();
              ++it)
             {
             if( workspace()->hasClient( *it ) && (num == 0) ) // safety
diff --git a/useractions.cpp b/useractions.cpp
index 25357e6613..8a26b88d71 100644
--- a/useractions.cpp
+++ b/useractions.cpp
@@ -1227,8 +1227,8 @@ void Client::setShortcut( const QString& _cut )
         }
     QList< KShortcut > keys;
     QStringList groups = cut.split( ' ');
-    for( QStringList::ConstIterator it = groups.begin();
-         it != groups.end();
+    for( QStringList::ConstIterator it = groups.constBegin();
+         it != groups.constEnd();
          ++it )
         {
         QRegExp reg( "(.*\\+)\\((.*)\\)" );
@@ -1246,15 +1246,15 @@ void Client::setShortcut( const QString& _cut )
                 }
             }
         }
-    for( QList< KShortcut >::ConstIterator it = keys.begin();
-         it != keys.end();
+    for( QList< KShortcut >::ConstIterator it = keys.constBegin();
+         it != keys.constEnd();
          ++it )
         {
         if( _shortcut == *it ) // current one is in the list
             return;
         }
-    for( QList< KShortcut >::ConstIterator it = keys.begin();
-         it != keys.end();
+    for( QList< KShortcut >::ConstIterator it = keys.constBegin();
+         it != keys.constEnd();
          ++it )
         {
         if( workspace()->shortcutAvailable( *it, this ))
@@ -1290,8 +1290,8 @@ void Client::delayedSetShortcut()
 bool Workspace::shortcutAvailable( const KShortcut& cut, Client* ignore ) const
     {
     // TODO check global shortcuts etc.
-    for( ClientList::ConstIterator it = clients.begin();
-         it != clients.end();
+    for( ClientList::ConstIterator it = clients.constBegin();
+         it != clients.constEnd();
          ++it )
         {
         if( (*it) != ignore && (*it)->shortcut() == cut )
diff --git a/workspace.cpp b/workspace.cpp
index 2f118bd3b7..9dbdd2154f 100644
--- a/workspace.cpp
+++ b/workspace.cpp
@@ -443,8 +443,8 @@ Workspace::~Workspace()
     blockStackingUpdates( true );
 // TODO    grabXServer();
     // use stacking_order, so that kwin --replace keeps stacking order
-    for( ClientList::ConstIterator it = stacking_order.begin();
-         it != stacking_order.end();
+    for( ClientList::ConstIterator it = stacking_order.constBegin();
+         it != stacking_order.constEnd();
          ++it )
         {
 	// only release the window
@@ -455,8 +455,8 @@ Workspace::~Workspace()
         clients.removeAll( *it );
         desktops.removeAll( *it );
         }
-    for( UnmanagedList::ConstIterator it = unmanaged.begin();
-         it != unmanaged.end();
+    for( UnmanagedList::ConstIterator it = unmanaged.constBegin();
+         it != unmanaged.constEnd();
          ++it )
         (*it)->release();
     delete tab_box;
@@ -760,8 +760,8 @@ void Workspace::updateCurrentTopMenu()
             {
             if( menu_client->isFullScreen())
                 block_desktop_menubar = true;
-            for( ClientList::ConstIterator it = menu_client->transients().begin();
-                 it != menu_client->transients().end();
+            for( ClientList::ConstIterator it = menu_client->transients().constBegin();
+                 it != menu_client->transients().constEnd();
                  ++it )
                 if( (*it)->isTopMenu())
                     {
@@ -776,8 +776,8 @@ void Workspace::updateCurrentTopMenu()
             }
         if( !menubar )
             { // try to find any topmenu from the application (#72113)
-            for( ClientList::ConstIterator it = active_client->group()->members().begin();
-                 it != active_client->group()->members().end();
+            for( ClientList::ConstIterator it = active_client->group()->members().constBegin();
+                 it != active_client->group()->members().constEnd();
                  ++it )
                 if( (*it)->isTopMenu())
                     {
@@ -792,8 +792,8 @@ void Workspace::updateCurrentTopMenu()
         Client* desktop = findDesktop( true, currentDesktop());
         if( desktop != NULL )
             {
-            for( ClientList::ConstIterator it = desktop->transients().begin();
-                 it != desktop->transients().end();
+            for( ClientList::ConstIterator it = desktop->transients().constBegin();
+                 it != desktop->transients().constEnd();
                  ++it )
                 if( (*it)->isTopMenu())
                     {
@@ -806,8 +806,8 @@ void Workspace::updateCurrentTopMenu()
         // thus the topmenu is not transient for it :-/.
         if( menubar == NULL )
             {
-            for( ClientList::ConstIterator it = topmenus.begin();
-                 it != topmenus.end();
+            for( ClientList::ConstIterator it = topmenus.constBegin();
+                 it != topmenus.constEnd();
                  ++it )
                 if( (*it)->wasOriginallyGroupTransient()) // kdesktop's topmenu has WM_TRANSIENT_FOR
                     {                                     // set pointing to the root window
@@ -836,7 +836,7 @@ void Workspace::updateCurrentTopMenu()
         }
 
     // ... then hide the other ones. Avoids flickers.
-    for ( ClientList::ConstIterator it = clients.begin(); it != clients.end(); ++it)
+    for ( ClientList::ConstIterator it = clients.constBegin(); it != clients.constEnd(); ++it)
         {
         if( (*it)->isTopMenu() && (*it) != menubar )
             (*it)->hideClient( true );
@@ -849,8 +849,8 @@ void Workspace::updateToolWindows( bool also_hide )
     // TODO what if Client's transiency/group changes? should this be called too? (I'm paranoid, am I not?)
     if( !options->hideUtilityWindowsForInactive )
         {
-        for( ClientList::ConstIterator it = clients.begin();
-             it != clients.end();
+        for( ClientList::ConstIterator it = clients.constBegin();
+             it != clients.constEnd();
              ++it )
             (*it)->hideClient( false );
         return;
@@ -875,8 +875,8 @@ void Workspace::updateToolWindows( bool also_hide )
 
     // SELI but maybe it should - what if a new client has been added that's not in stacking order yet?
     ClientList to_show, to_hide;
-    for( ClientList::ConstIterator it = stacking_order.begin();
-         it != stacking_order.end();
+    for( ClientList::ConstIterator it = stacking_order.constBegin();
+         it != stacking_order.constEnd();
          ++it )
         {
         if( (*it)->isUtility() || (*it)->isMenu() || (*it)->isToolbar())
@@ -907,8 +907,8 @@ void Workspace::updateToolWindows( bool also_hide )
                 // have e.g. kicker as mainwindow
                 if( mainclients.isEmpty())
                     show = true;
-                for( ClientList::ConstIterator it2 = mainclients.begin();
-                     it2 != mainclients.end();
+                for( ClientList::ConstIterator it2 = mainclients.constBegin();
+                     it2 != mainclients.constEnd();
                      ++it2 )
                     {
                     if( (*it2)->isSpecialWindow())
@@ -928,8 +928,8 @@ void Workspace::updateToolWindows( bool also_hide )
             to_show.at( i )->hideClient( false );
     if( also_hide )
         {
-        for( ClientList::ConstIterator it = to_hide.begin();
-             it != to_hide.end();
+        for( ClientList::ConstIterator it = to_hide.constBegin();
+             it != to_hide.constEnd();
              ++it ) // from bottommost
             (*it)->hideClient( true );
         updateToolWindowsTimer.stop();
@@ -1020,8 +1020,8 @@ void Workspace::slotReconfigure()
         curtain.setGeometry( QApplication::desktop()->geometry() );
         curtain.show();
 #endif
-        for( ClientList::ConstIterator it = clients.begin();
-                it != clients.end();
+        for( ClientList::ConstIterator it = clients.constBegin();
+                it != clients.constEnd();
                 ++it )
             {
             (*it)->updateDecoration( true, true );
@@ -1269,8 +1269,8 @@ void ObscuringWindows::create( Client* c )
 ObscuringWindows::~ObscuringWindows()
     {
     max_cache_size = qMax( ( int )max_cache_size, obscuring_windows.count() + 4 ) - 1;
-    for( QList<Window>::ConstIterator it = obscuring_windows.begin();
-         it != obscuring_windows.end();
+    for( QList<Window>::ConstIterator it = obscuring_windows.constBegin();
+         it != obscuring_windows.constEnd();
          ++it )
         {
         XUnmapWindow( display(), *it );
@@ -1312,7 +1312,7 @@ bool Workspace::setCurrentDesktop( int new_desktop )
 
         current_desktop = new_desktop; // change the desktop (so that Client::updateVisibility() works)
 
-        for ( ClientList::ConstIterator it = stacking_order.begin(); it != stacking_order.end(); ++it)
+        for ( ClientList::ConstIterator it = stacking_order.constBegin(); it != stacking_order.constEnd(); ++it)
             if ( !(*it)->isOnDesktop( new_desktop ) && (*it) != movingClient )
                 {
                 if( (*it)->isShown( true ) && (*it)->isOnDesktop( old_desktop ))
@@ -1581,8 +1581,8 @@ void Workspace::setNumberOfDesktops( int n )
     // windows that would be hidden to the last visible desktop
     if( old_number_of_desktops > number_of_desktops )
         {
-        for( ClientList::ConstIterator it = clients.begin();
-              it != clients.end();
+        for( ClientList::ConstIterator it = clients.constBegin();
+              it != clients.constEnd();
               ++it)
             {
             if( !(*it)->isOnAllDesktops() && (*it)->desktop() > numberOfDesktops())
@@ -1635,8 +1635,8 @@ void Workspace::sendClientToDesktop( Client* c, int desk, bool dont_activate )
         }
 
     ClientList transients_stacking_order = ensureStackingOrder( c->transients());
-    for( ClientList::ConstIterator it = transients_stacking_order.begin();
-         it != transients_stacking_order.end();
+    for( ClientList::ConstIterator it = transients_stacking_order.constBegin();
+         it != transients_stacking_order.constEnd();
          ++it )
         sendClientToDesktop( *it, desk, dont_activate );
     updateClientArea();
@@ -1708,8 +1708,8 @@ void Workspace::sendClientToScreen( Client* c, int screen )
         c->size().width(), c->size().height());
     c->checkWorkspacePosition();
     ClientList transients_stacking_order = ensureStackingOrder( c->transients());
-    for( ClientList::ConstIterator it = transients_stacking_order.begin();
-         it != transients_stacking_order.end();
+    for( ClientList::ConstIterator it = transients_stacking_order.constBegin();
+         it != transients_stacking_order.constEnd();
          ++it )
         sendClientToScreen( *it, screen );
     if( c->isActive())
@@ -2374,8 +2374,8 @@ void Workspace::lostTopMenuSelection()
     delete topmenu_space;
     topmenu_space = NULL;
     updateClientArea();
-    for( ClientList::ConstIterator it = topmenus.begin();
-         it != topmenus.end();
+    for( ClientList::ConstIterator it = topmenus.constBegin();
+         it != topmenus.constEnd();
          ++it )
         (*it)->checkWorkspacePosition();
     }
@@ -2523,15 +2523,15 @@ void Workspace::setShowingDesktop( bool showing )
         ClientList cls = stackingOrder();
         // find them first, then minimize, otherwise transients may get minimized with the window
         // they're transient for
-        for( ClientList::ConstIterator it = cls.begin();
-             it != cls.end();
+        for( ClientList::ConstIterator it = cls.constBegin();
+             it != cls.constEnd();
              ++it )
             {
             if( (*it)->isOnCurrentDesktop() && (*it)->isShown( true ) && !(*it)->isSpecialWindow())
                 showing_desktop_clients.prepend( *it ); // topmost first to reduce flicker
             }
-        for( ClientList::ConstIterator it = showing_desktop_clients.begin();
-             it != showing_desktop_clients.end();
+        for( ClientList::ConstIterator it = showing_desktop_clients.constBegin();
+             it != showing_desktop_clients.constEnd();
              ++it )
             (*it)->minimize();
         --block_focus;
@@ -2540,8 +2540,8 @@ void Workspace::setShowingDesktop( bool showing )
         }
     else
         {
-        for( ClientList::ConstIterator it = showing_desktop_clients.begin();
-             it != showing_desktop_clients.end();
+        for( ClientList::ConstIterator it = showing_desktop_clients.constBegin();
+             it != showing_desktop_clients.constEnd();
              ++it )
             (*it)->unminimize();
         if( showing_desktop_clients.count() > 0 )
@@ -2569,8 +2569,8 @@ void Workspace::resetShowingDesktop( bool keep_hidden )
     ++block_showing_desktop;
     if( !keep_hidden )
         {
-        for( ClientList::ConstIterator it = showing_desktop_clients.begin();
-             it != showing_desktop_clients.end();
+        for( ClientList::ConstIterator it = showing_desktop_clients.constBegin();
+             it != showing_desktop_clients.constEnd();
              ++it )
             (*it)->unminimize();
         }
@@ -2627,8 +2627,8 @@ void Workspace::slotBlockShortcuts( int data )
         global_shortcuts_disabled_for_client = false;
         }
     // update also Alt+LMB actions etc.
-    for( ClientList::ConstIterator it = clients.begin();
-         it != clients.end();
+    for( ClientList::ConstIterator it = clients.constBegin();
+         it != clients.constEnd();
          ++it )
         (*it)->updateMouseGrab();
     }
diff --git a/workspace.h b/workspace.h
index 9203c601fd..32a928ddff 100644
--- a/workspace.h
+++ b/workspace.h
@@ -944,10 +944,10 @@ inline Client* Workspace::findClient( T predicate ) const
 template< typename T1, typename T2 >
 inline void Workspace::forEachClient( T1 procedure, T2 predicate )
     {
-    for ( ClientList::ConstIterator it = clients.begin(); it != clients.end(); ++it)
+    for ( ClientList::ConstIterator it = clients.constBegin(); it != clients.constEnd(); ++it)
         if ( predicate( const_cast< const Client* >( *it)))
             procedure( *it );
-    for ( ClientList::ConstIterator it = desktops.begin(); it != desktops.end(); ++it)
+    for ( ClientList::ConstIterator it = desktops.constBegin(); it != desktops.constEnd(); ++it)
         if ( predicate( const_cast< const Client* >( *it)))
             procedure( *it );
     }
@@ -967,7 +967,7 @@ inline Unmanaged* Workspace::findUnmanaged( T predicate ) const
 template< typename T1, typename T2 >
 inline void Workspace::forEachUnmanaged( T1 procedure, T2 predicate )
     {
-    for ( UnmanagedList::ConstIterator it = unmanaged.begin(); it != unmanaged.end(); ++it)
+    for ( UnmanagedList::ConstIterator it = unmanaged.constBegin(); it != unmanaged.constEnd(); ++it)
         if ( predicate( const_cast< const Unmanaged* >( *it)))
             procedure( *it );
     }