diff --git a/src/core/layertree/qgslayertreemodel.cpp b/src/core/layertree/qgslayertreemodel.cpp
index b3223fa7d68..00f375f75a0 100644
--- a/src/core/layertree/qgslayertreemodel.cpp
+++ b/src/core/layertree/qgslayertreemodel.cpp
@@ -614,7 +614,8 @@ void QgsLayerTreeModel::setLegendFilterByScale( double scale )
 
   // this could be later done in more efficient way
   // by just updating active legend nodes, without refreshing original legend nodes
-  Q_FOREACH ( QgsLayerTreeLayer *nodeLayer, mRootNode->findLayers() )
+  const auto constFindLayers = mRootNode->findLayers();
+  for ( QgsLayerTreeLayer *nodeLayer : constFindLayers )
     refreshLayerLegend( nodeLayer );
 }
 
@@ -634,7 +635,8 @@ void QgsLayerTreeModel::setLegendFilter( const QgsMapSettings *settings, bool us
     // collect expression filters
     if ( useExpressions )
     {
-      Q_FOREACH ( QgsLayerTreeLayer *nodeLayer, mRootNode->findLayers() )
+      const auto constFindLayers = mRootNode->findLayers();
+      for ( QgsLayerTreeLayer *nodeLayer : constFindLayers )
       {
         bool enabled;
         QString expr = QgsLayerTreeUtils::legendFilterByExpression( *nodeLayer, &enabled );
@@ -670,7 +672,8 @@ void QgsLayerTreeModel::setLegendFilter( const QgsMapSettings *settings, bool us
 
   // this could be later done in more efficient way
   // by just updating active legend nodes, without refreshing original legend nodes
-  Q_FOREACH ( QgsLayerTreeLayer *nodeLayer, mRootNode->findLayers() )
+  const auto constFindLayers = mRootNode->findLayers();
+  for ( QgsLayerTreeLayer *nodeLayer : constFindLayers )
     refreshLayerLegend( nodeLayer );
 
   setAutoCollapseLegendNodes( bkAutoCollapse );
@@ -902,7 +905,8 @@ void QgsLayerTreeModel::connectToLayer( QgsLayerTreeLayer *nodeLayer )
 static int _numLayerCount( QgsLayerTreeGroup *group, const QString &layerId )
 {
   int count = 0;
-  Q_FOREACH ( QgsLayerTreeNode *child, group->children() )
+  const auto constChildren = group->children();
+  for ( QgsLayerTreeNode *child : constChildren )
   {
     if ( QgsLayerTree::isLayer( child ) )
     {
@@ -938,7 +942,8 @@ void QgsLayerTreeModel::disconnectFromLayer( QgsLayerTreeLayer *nodeLayer )
 
 void QgsLayerTreeModel::connectToLayers( QgsLayerTreeGroup *parentGroup )
 {
-  Q_FOREACH ( QgsLayerTreeNode *node, parentGroup->children() )
+  const auto constChildren = parentGroup->children();
+  for ( QgsLayerTreeNode *node : constChildren )
   {
     if ( QgsLayerTree::isGroup( node ) )
       connectToLayers( QgsLayerTree::toGroup( node ) );
@@ -949,7 +954,8 @@ void QgsLayerTreeModel::connectToLayers( QgsLayerTreeGroup *parentGroup )
 
 void QgsLayerTreeModel::disconnectFromLayers( QgsLayerTreeGroup *parentGroup )
 {
-  Q_FOREACH ( QgsLayerTreeNode *node, parentGroup->children() )
+  const auto constChildren = parentGroup->children();
+  for ( QgsLayerTreeNode *node : constChildren )
   {
     if ( QgsLayerTree::isGroup( node ) )
       disconnectFromLayers( QgsLayerTree::toGroup( node ) );
diff --git a/src/core/layertree/qgslayertreenode.cpp b/src/core/layertree/qgslayertreenode.cpp
index 60daad9ddd5..5118645065e 100644
--- a/src/core/layertree/qgslayertreenode.cpp
+++ b/src/core/layertree/qgslayertreenode.cpp
@@ -142,7 +142,8 @@ void fetchCheckedLayers( const QgsLayerTreeNode *node, QList<QgsMapLayer *> &lay
       layers << nodeLayer->layer();
   }
 
-  Q_FOREACH ( QgsLayerTreeNode *child, node->children() )
+  const auto constChildren = node->children();
+  for ( QgsLayerTreeNode *child : constChildren )
     fetchCheckedLayers( child, layers );
 }
 
diff --git a/src/core/layertree/qgslayertreeutils.cpp b/src/core/layertree/qgslayertreeutils.cpp
index c259a53654f..d2168cd9215 100644
--- a/src/core/layertree/qgslayertreeutils.cpp
+++ b/src/core/layertree/qgslayertreeutils.cpp
@@ -154,7 +154,8 @@ static QDomElement _writeOldLegendGroup( QDomDocument &doc, QgsLayerTreeGroup *n
 
 static void _writeOldLegendGroupChildren( QDomDocument &doc, QDomElement &groupElem, QgsLayerTreeGroup *nodeGroup, bool hasCustomOrder, const QList<QgsMapLayer *> &order )
 {
-  Q_FOREACH ( QgsLayerTreeNode *node, nodeGroup->children() )
+  const auto constChildren = nodeGroup->children();
+  for ( QgsLayerTreeNode *node : constChildren )
   {
     if ( QgsLayerTree::isGroup( node ) )
     {
@@ -294,7 +295,8 @@ bool QgsLayerTreeUtils::layersModified( const QList<QgsLayerTreeLayer *> &layerN
 void QgsLayerTreeUtils::removeInvalidLayers( QgsLayerTreeGroup *group )
 {
   QList<QgsLayerTreeNode *> nodesToRemove;
-  Q_FOREACH ( QgsLayerTreeNode *node, group->children() )
+  const auto constChildren = group->children();
+  for ( QgsLayerTreeNode *node : constChildren )
   {
     if ( QgsLayerTree::isGroup( node ) )
       removeInvalidLayers( QgsLayerTree::toGroup( node ) );
@@ -382,7 +384,8 @@ QStringList QgsLayerTreeUtils::invisibleLayerList( QgsLayerTreeNode *node )
 
 void QgsLayerTreeUtils::replaceChildrenOfEmbeddedGroups( QgsLayerTreeGroup *group )
 {
-  Q_FOREACH ( QgsLayerTreeNode *child, group->children() )
+  const auto constChildren = group->children();
+  for ( QgsLayerTreeNode *child : constChildren )
   {
     if ( QgsLayerTree::isGroup( child ) )
     {
@@ -402,7 +405,8 @@ void QgsLayerTreeUtils::replaceChildrenOfEmbeddedGroups( QgsLayerTreeGroup *grou
 
 void QgsLayerTreeUtils::updateEmbeddedGroupsProjectPath( QgsLayerTreeGroup *group, const QgsProject *project )
 {
-  Q_FOREACH ( QgsLayerTreeNode *node, group->children() )
+  const auto constChildren = group->children();
+  for ( QgsLayerTreeNode *node : constChildren )
   {
     if ( !node->customProperty( QStringLiteral( "embedded_project" ) ).toString().isEmpty() )
     {
@@ -433,7 +437,8 @@ QString QgsLayerTreeUtils::legendFilterByExpression( const QgsLayerTreeLayer &la
 
 bool QgsLayerTreeUtils::hasLegendFilterExpression( const QgsLayerTreeGroup &group )
 {
-  Q_FOREACH ( QgsLayerTreeLayer *l, group.findLayers() )
+  const auto constFindLayers = group.findLayers();
+  for ( QgsLayerTreeLayer *l : constFindLayers )
   {
     bool exprEnabled;
     QString expr = legendFilterByExpression( *l, &exprEnabled );
@@ -453,7 +458,8 @@ QgsLayerTreeLayer *QgsLayerTreeUtils::insertLayerBelow( QgsLayerTreeGroup *group
     return nullptr;
 
   int idx = 0;
-  Q_FOREACH ( QgsLayerTreeNode *vl, inTree->parent()->children() )
+  const auto constChildren = inTree->parent()->children();
+  for ( QgsLayerTreeNode *vl : constChildren )
   {
     if ( vl->nodeType() == QgsLayerTreeNode::NodeLayer && static_cast<QgsLayerTreeLayer *>( vl )->layer() == refLayer )
     {
diff --git a/src/core/layout/qgslayoutitemlegend.cpp b/src/core/layout/qgslayoutitemlegend.cpp
index dee7f7e91e8..4f5f2f4f408 100644
--- a/src/core/layout/qgslayoutitemlegend.cpp
+++ b/src/core/layout/qgslayoutitemlegend.cpp
@@ -744,7 +744,8 @@ void QgsLayoutItemLegend::mapLayerStyleOverridesChanged()
   {
     mLegendModel->setLayerStyleOverrides( mMap->layerStyleOverrides() );
 
-    Q_FOREACH ( QgsLayerTreeLayer *nodeLayer, mLegendModel->rootGroup()->findLayers() )
+    const auto constFindLayers = mLegendModel->rootGroup()->findLayers();
+    for ( QgsLayerTreeLayer *nodeLayer : constFindLayers )
       mLegendModel->refreshLayerLegend( nodeLayer );
   }
 
diff --git a/src/core/metadata/qgslayermetadatavalidator.cpp b/src/core/metadata/qgslayermetadatavalidator.cpp
index ac51664610e..1708fb4438d 100644
--- a/src/core/metadata/qgslayermetadatavalidator.cpp
+++ b/src/core/metadata/qgslayermetadatavalidator.cpp
@@ -94,7 +94,8 @@ bool QgsNativeMetadataBaseValidator::validate( const QgsAbstractMetadataBase *me
 
   // validate contacts
   index = 0;
-  Q_FOREACH ( const QgsAbstractMetadataBase::Contact &contact, metadata->contacts() )
+  const auto constContacts = metadata->contacts();
+  for ( const QgsAbstractMetadataBase::Contact &contact : constContacts )
   {
     if ( contact.name.isEmpty() )
     {
@@ -106,7 +107,8 @@ bool QgsNativeMetadataBaseValidator::validate( const QgsAbstractMetadataBase *me
 
   // validate links
   index = 0;
-  Q_FOREACH ( const QgsAbstractMetadataBase::Link &link, metadata->links() )
+  const auto constLinks = metadata->links();
+  for ( const QgsAbstractMetadataBase::Link &link : constLinks )
   {
     if ( link.name.isEmpty() )
     {
@@ -158,7 +160,8 @@ bool QgsNativeMetadataValidator::validate( const QgsAbstractMetadataBase *baseMe
   }
 
   int index = 0;
-  Q_FOREACH ( const QgsLayerMetadata::SpatialExtent &extent, metadata->extent().spatialExtents() )
+  const auto constSpatialExtents = metadata->extent().spatialExtents();
+  for ( const QgsLayerMetadata::SpatialExtent &extent : constSpatialExtents )
   {
     if ( !extent.extentCrs.isValid() )
     {
diff --git a/src/core/processing/models/qgsprocessingmodelalgorithm.cpp b/src/core/processing/models/qgsprocessingmodelalgorithm.cpp
index 185a349a6fc..b43a53097aa 100644
--- a/src/core/processing/models/qgsprocessingmodelalgorithm.cpp
+++ b/src/core/processing/models/qgsprocessingmodelalgorithm.cpp
@@ -99,7 +99,8 @@ QgsProcessingAlgorithm::Flags QgsProcessingModelAlgorithm::flags() const
 QVariantMap QgsProcessingModelAlgorithm::parametersForChildAlgorithm( const QgsProcessingModelChildAlgorithm &child, const QVariantMap &modelParameters, const QVariantMap &results, const QgsExpressionContext &expressionContext ) const
 {
   QVariantMap childParams;
-  Q_FOREACH ( const QgsProcessingParameterDefinition *def, child.algorithm()->parameterDefinitions() )
+  const auto constParameterDefinitions = child.algorithm()->parameterDefinitions();
+  for ( const QgsProcessingParameterDefinition *def : constParameterDefinitions )
   {
     if ( !def->isDestination() )
     {
@@ -219,7 +220,8 @@ bool QgsProcessingModelAlgorithm::childOutputIsRequired( const QString &childId,
     QMap<QString, QgsProcessingModelChildParameterSources>::const_iterator childParamIt = candidateChildParams.constBegin();
     for ( ; childParamIt != candidateChildParams.constEnd(); ++childParamIt )
     {
-      Q_FOREACH ( const QgsProcessingModelChildParameterSource &source, childParamIt.value() )
+      const auto constValue = childParamIt.value();
+      for ( const QgsProcessingModelChildParameterSource &source : constValue )
       {
         if ( source.source() == QgsProcessingModelChildParameterSource::ChildOutput
              && source.outputChildId() == childId
@@ -869,7 +871,8 @@ QgsProcessingModelChildParameterSources QgsProcessingModelAlgorithm::availableSo
             continue;
 
           bool ok = sourceDef->dataTypes().isEmpty();
-          Q_FOREACH ( int type, sourceDef->dataTypes() )
+          const auto constDataTypes = sourceDef->dataTypes();
+          for ( int type : constDataTypes )
           {
             if ( dataTypes.contains( type ) || type == QgsProcessing::TypeMapLayer || type == QgsProcessing::TypeVector || type == QgsProcessing::TypeVectorAnyGeometry )
             {
@@ -905,7 +908,8 @@ QgsProcessingModelChildParameterSources QgsProcessingModelAlgorithm::availableSo
     if ( !alg )
       continue;
 
-    Q_FOREACH ( const QgsProcessingOutputDefinition *out, alg->outputDefinitions() )
+    const auto constOutputDefinitions = alg->outputDefinitions();
+    for ( const QgsProcessingOutputDefinition *out : constOutputDefinitions )
     {
       if ( outputTypes.contains( out->type() ) )
       {
@@ -1283,7 +1287,8 @@ bool QgsProcessingModelAlgorithm::childAlgorithmsDependOnParameter( const QStrin
     QMap<QString, QgsProcessingModelChildParameterSources>::const_iterator paramIt = childParams.constBegin();
     for ( ; paramIt != childParams.constEnd(); ++paramIt )
     {
-      Q_FOREACH ( const QgsProcessingModelChildParameterSource &source, paramIt.value() )
+      const auto constValue = paramIt.value();
+      for ( const QgsProcessingModelChildParameterSource &source : constValue )
       {
         if ( source.source() == QgsProcessingModelChildParameterSource::ModelParameter
              && source.parameterName() == name )
@@ -1336,7 +1341,8 @@ void QgsProcessingModelAlgorithm::dependentChildAlgorithmsRecursive( const QStri
     QMap<QString, QgsProcessingModelChildParameterSources>::const_iterator paramIt = childParams.constBegin();
     for ( ; paramIt != childParams.constEnd(); ++paramIt )
     {
-      Q_FOREACH ( const QgsProcessingModelChildParameterSource &source, paramIt.value() )
+      const auto constValue = paramIt.value();
+      for ( const QgsProcessingModelChildParameterSource &source : constValue )
       {
         if ( source.source() == QgsProcessingModelChildParameterSource::ChildOutput
              && source.outputChildId() == childId )
@@ -1372,7 +1378,8 @@ void QgsProcessingModelAlgorithm::dependsOnChildAlgorithmsRecursive( const QStri
   const QgsProcessingModelChildAlgorithm &alg = mChildAlgorithms.value( childId );
 
   // add direct dependencies
-  Q_FOREACH ( const QString &c, alg.dependencies() )
+  const auto constDependencies = alg.dependencies();
+  for ( const QString &c : constDependencies )
   {
     if ( !depends.contains( c ) )
     {
@@ -1386,7 +1393,8 @@ void QgsProcessingModelAlgorithm::dependsOnChildAlgorithmsRecursive( const QStri
   QMap<QString, QgsProcessingModelChildParameterSources>::const_iterator paramIt = childParams.constBegin();
   for ( ; paramIt != childParams.constEnd(); ++paramIt )
   {
-    Q_FOREACH ( const QgsProcessingModelChildParameterSource &source, paramIt.value() )
+    const auto constValue = paramIt.value();
+    for ( const QgsProcessingModelChildParameterSource &source : constValue )
     {
       if ( source.source() == QgsProcessingModelChildParameterSource::ChildOutput && !depends.contains( source.outputChildId() ) )
       {
diff --git a/src/core/processing/models/qgsprocessingmodelchildalgorithm.cpp b/src/core/processing/models/qgsprocessingmodelchildalgorithm.cpp
index 207499a8c3a..e2eebec6be8 100644
--- a/src/core/processing/models/qgsprocessingmodelchildalgorithm.cpp
+++ b/src/core/processing/models/qgsprocessingmodelchildalgorithm.cpp
@@ -98,7 +98,8 @@ QVariant QgsProcessingModelChildAlgorithm::toVariant() const
   for ( ; paramIt != mParams.constEnd(); ++paramIt )
   {
     QVariantList sources;
-    Q_FOREACH ( const QgsProcessingModelChildParameterSource &source, paramIt.value() )
+    const auto constValue = paramIt.value();
+    for ( const QgsProcessingModelChildParameterSource &source : constValue )
     {
       sources << source.toVariant();
     }
@@ -137,7 +138,8 @@ bool QgsProcessingModelChildAlgorithm::loadVariant( const QVariant &child )
   for ( ; paramIt != paramMap.constEnd(); ++paramIt )
   {
     QgsProcessingModelChildParameterSources sources;
-    Q_FOREACH ( const QVariant &sourceVar, paramIt->toList() )
+    const auto constToList = paramIt->toList();
+    for ( const QVariant &sourceVar : constToList )
     {
       QgsProcessingModelChildParameterSource param;
       if ( !param.loadVariant( sourceVar.toMap() ) )
diff --git a/src/core/processing/qgsprocessingparameters.cpp b/src/core/processing/qgsprocessingparameters.cpp
index 4715eae1d74..524c94da6f6 100644
--- a/src/core/processing/qgsprocessingparameters.cpp
+++ b/src/core/processing/qgsprocessingparameters.cpp
@@ -287,7 +287,8 @@ QList<int> QgsProcessingParameters::parameterAsEnums( const QgsProcessingParamet
     resultList << val.value< QgsProperty >().valueAsString( context.expressionContext(), definition->defaultValue().toString() );
   else if ( val.type() == QVariant::List )
   {
-    Q_FOREACH ( const QVariant &var, val.toList() )
+    const auto constToList = val.toList();
+    for ( const QVariant &var : constToList )
       resultList << var;
   }
   else if ( val.type() == QVariant::String )
@@ -307,7 +308,8 @@ QList<int> QgsProcessingParameters::parameterAsEnums( const QgsProcessingParamet
     // check default
     if ( definition->defaultValue().type() == QVariant::List )
     {
-      Q_FOREACH ( const QVariant &var, definition->defaultValue().toList() )
+      const auto constToList = definition->defaultValue().toList();
+      for ( const QVariant &var : constToList )
         resultList << var;
     }
     else if ( definition->defaultValue().type() == QVariant::String )
@@ -1313,14 +1315,16 @@ QList<QgsMapLayer *> QgsProcessingParameters::parameterAsLayerList( const QgsPro
   {
     if ( var.type() == QVariant::List )
     {
-      Q_FOREACH ( const QVariant &listVar, var.toList() )
+      const auto constToList = var.toList();
+      for ( const QVariant &listVar : constToList )
       {
         processVariant( listVar );
       }
     }
     else if ( var.type() == QVariant::StringList )
     {
-      Q_FOREACH ( const QString &s, var.toStringList() )
+      const auto constToStringList = var.toStringList();
+      for ( const QString &s : constToStringList )
       {
         processVariant( s );
       }
@@ -1360,7 +1364,8 @@ QList<QgsMapLayer *> QgsProcessingParameters::parameterAsLayerList( const QgsPro
     }
     else if ( definition->defaultValue().type() == QVariant::List )
     {
-      Q_FOREACH ( const QVariant &var, definition->defaultValue().toList() )
+      const auto constToList = definition->defaultValue().toList();
+      for ( const QVariant &var : constToList )
       {
         if ( QgsMapLayer *layer = qobject_cast< QgsMapLayer * >( qvariant_cast<QObject *>( var ) ) )
         {
@@ -1398,7 +1403,8 @@ QList<double> QgsProcessingParameters::parameterAsRange( const QgsProcessingPara
     resultStringList << val.value< QgsProperty >().valueAsString( context.expressionContext(), definition->defaultValue().toString() );
   else if ( val.type() == QVariant::List )
   {
-    Q_FOREACH ( const QVariant &var, val.toList() )
+    const auto constToList = val.toList();
+    for ( const QVariant &var : constToList )
       resultStringList << var.toString();
   }
   else
@@ -1410,7 +1416,8 @@ QList<double> QgsProcessingParameters::parameterAsRange( const QgsProcessingPara
     // check default
     if ( definition->defaultValue().type() == QVariant::List )
     {
-      Q_FOREACH ( const QVariant &var, definition->defaultValue().toList() )
+      const auto constToList = definition->defaultValue().toList();
+      for ( const QVariant &var : constToList )
         resultStringList << var.toString();
     }
     else
@@ -1450,7 +1457,8 @@ QStringList QgsProcessingParameters::parameterAsFields( const QgsProcessingParam
       resultStringList << val.value< QgsProperty >().valueAsString( context.expressionContext(), definition->defaultValue().toString() );
     else if ( val.type() == QVariant::List )
     {
-      Q_FOREACH ( const QVariant &var, val.toList() )
+      const auto constToList = val.toList();
+      for ( const QVariant &var : constToList )
         resultStringList << var.toString();
     }
     else
@@ -1465,7 +1473,8 @@ QStringList QgsProcessingParameters::parameterAsFields( const QgsProcessingParam
     {
       if ( definition->defaultValue().type() == QVariant::List )
       {
-        Q_FOREACH ( const QVariant &var, definition->defaultValue().toList() )
+        const auto constToList = definition->defaultValue().toList();
+        for ( const QVariant &var : constToList )
           resultStringList << var.toString();
       }
       else
@@ -2353,7 +2362,8 @@ QString QgsProcessingParameterMatrix::valueAsPythonString( const QVariant &value
     if ( v.type() == QVariant::List )
     {
       QStringList parts2;
-      Q_FOREACH ( const QVariant &v2, v.toList() )
+      const auto constToList = v.toList();
+      for ( const QVariant &v2 : constToList )
       {
         if ( v2.isNull() || !v2.isValid() )
           parts2 << QStringLiteral( "None" );
@@ -2503,7 +2513,8 @@ bool QgsProcessingParameterMultipleLayers::checkValueIsAcceptable( const QVarian
     if ( !context )
       return true;
 
-    Q_FOREACH ( const QVariant &v, input.toList() )
+    const auto constToList = input.toList();
+    for ( const QVariant &v : constToList )
     {
       if ( qobject_cast< QgsMapLayer * >( qvariant_cast<QObject *>( v ) ) )
         continue;
@@ -2524,7 +2535,8 @@ bool QgsProcessingParameterMultipleLayers::checkValueIsAcceptable( const QVarian
     if ( !context )
       return true;
 
-    Q_FOREACH ( const QString &v, input.toStringList() )
+    const auto constToStringList = input.toStringList();
+    for ( const QString &v : constToStringList )
     {
       if ( !QgsProcessingUtils::mapLayerFromString( v, *context ) )
         return false;
@@ -2582,7 +2594,8 @@ QString QgsProcessingParameterMultipleLayers::asScriptCode() const
   if ( mDefault.type() == QVariant::List )
   {
     QStringList parts;
-    Q_FOREACH ( const QVariant &var, mDefault.toList() )
+    const auto constToList = mDefault.toList();
+    for ( const QVariant &var : constToList )
     {
       parts << var.toString();
     }
@@ -3097,7 +3110,8 @@ QString QgsProcessingParameterEnum::valueAsPythonString( const QVariant &value,
   if ( value.type() == QVariant::List )
   {
     QStringList parts;
-    Q_FOREACH ( const QVariant &val, value.toList() )
+    const auto constToList = value.toList();
+    for ( const QVariant &val : constToList )
     {
       parts << QString::number( static_cast< int >( val.toDouble() ) );
     }
@@ -3723,7 +3737,8 @@ QString QgsProcessingParameterField::valueAsPythonString( const QVariant &value,
   if ( value.type() == QVariant::List )
   {
     QStringList parts;
-    Q_FOREACH ( const QVariant &val, value.toList() )
+    const auto constToList = value.toList();
+    for ( const QVariant &val : constToList )
     {
       parts << QgsProcessingUtils::stringToPythonLiteral( val.toString() );
     }
@@ -3732,7 +3747,8 @@ QString QgsProcessingParameterField::valueAsPythonString( const QVariant &value,
   else if ( value.type() == QVariant::StringList )
   {
     QStringList parts;
-    Q_FOREACH ( QString s, value.toStringList() )
+    const auto constToStringList = value.toStringList();
+    for ( QString s : constToStringList )
     {
       parts << QgsProcessingUtils::stringToPythonLiteral( s );
     }
diff --git a/src/core/processing/qgsprocessingregistry.cpp b/src/core/processing/qgsprocessingregistry.cpp
index 9de9992d667..1ae5028d92a 100644
--- a/src/core/processing/qgsprocessingregistry.cpp
+++ b/src/core/processing/qgsprocessingregistry.cpp
@@ -138,7 +138,8 @@ const QgsProcessingAlgorithm *QgsProcessingRegistry::algorithmById( const QStrin
   QMap<QString, QgsProcessingProvider *>::const_iterator it = mProviders.constBegin();
   for ( ; it != mProviders.constEnd(); ++it )
   {
-    Q_FOREACH ( const QgsProcessingAlgorithm *alg, it.value()->algorithms() )
+    const auto constAlgorithms = it.value()->algorithms();
+    for ( const QgsProcessingAlgorithm *alg : constAlgorithms )
       if ( alg->id() == id )
         return alg;
   }
diff --git a/src/core/qgsblockingnetworkrequest.cpp b/src/core/qgsblockingnetworkrequest.cpp
index 6dc09cf7037..c0921b3d4c9 100644
--- a/src/core/qgsblockingnetworkrequest.cpp
+++ b/src/core/qgsblockingnetworkrequest.cpp
@@ -333,7 +333,8 @@ void QgsBlockingNetworkRequest::replyFinished()
           QNetworkCacheMetaData cmd = nam->cache()->metaData( mReply->request().url() );
 
           QNetworkCacheMetaData::RawHeaderList hl;
-          Q_FOREACH ( const QNetworkCacheMetaData::RawHeader &h, cmd.rawHeaders() )
+          const auto constRawHeaders = cmd.rawHeaders();
+          for ( const QNetworkCacheMetaData::RawHeader &h : constRawHeaders )
           {
             if ( h.first != "Cache-Control" )
               hl.append( h );
diff --git a/src/core/qgsbrowsermodel.cpp b/src/core/qgsbrowsermodel.cpp
index e4b05b061d6..46c2717290b 100644
--- a/src/core/qgsbrowsermodel.cpp
+++ b/src/core/qgsbrowsermodel.cpp
@@ -147,7 +147,8 @@ void QgsBrowserModel::addRootItems()
   }
 
   // add as sorted groups by QgsDataProvider::DataCapability enum
-  Q_FOREACH ( int key, providerMap.uniqueKeys() )
+  const auto constUniqueKeys = providerMap.uniqueKeys();
+  for ( int key : constUniqueKeys )
   {
     QList<QgsDataItem *> providerGroup = providerMap.values( key );
     if ( providerGroup.size() > 1 )
diff --git a/src/core/qgsdatasourceuri.cpp b/src/core/qgsdatasourceuri.cpp
index 0829e63330b..2625349d680 100644
--- a/src/core/qgsdatasourceuri.cpp
+++ b/src/core/qgsdatasourceuri.cpp
@@ -588,8 +588,9 @@ void QgsDataSourceUri::setEncodedUri( const QByteArray &uri )
   mParams.clear();
   QUrl url;
   url.setEncodedQuery( uri );
-  QPair<QString, QString> item;
-  Q_FOREACH ( item, url.queryItems() )
+
+  const auto constQueryItems = url.queryItems();
+  for ( const QPair<QString, QString> &item : constQueryItems )
   {
     mParams.insertMulti( item.first, item.second );
   }
diff --git a/src/core/qgsdiagramrenderer.cpp b/src/core/qgsdiagramrenderer.cpp
index f97cfba5e10..7faa128c91b 100644
--- a/src/core/qgsdiagramrenderer.cpp
+++ b/src/core/qgsdiagramrenderer.cpp
@@ -474,7 +474,8 @@ QSet<QString> QgsDiagramRenderer::referencedFields( const QgsExpressionContext &
   Q_FOREACH ( const QString &att, diagramAttributes() )
   {
     QgsExpression *expression = mDiagram->getExpression( att, context );
-    Q_FOREACH ( const QString &field, expression->referencedColumns() )
+    const auto constReferencedColumns = expression->referencedColumns();
+    for ( const QString &field : constReferencedColumns )
     {
       referenced << field;
     }
@@ -632,7 +633,8 @@ QSet<QString> QgsLinearlyInterpolatedDiagramRenderer::referencedFields( const Qg
   if ( mInterpolationSettings.classificationAttributeIsExpression )
   {
     QgsExpression *expression = mDiagram->getExpression( mInterpolationSettings.classificationAttributeExpression, context );
-    Q_FOREACH ( const QString &field, expression->referencedColumns() )
+    const auto constReferencedColumns = expression->referencedColumns();
+    for ( const QString &field : constReferencedColumns )
     {
       referenced << field;
     }
@@ -786,7 +788,8 @@ QList< QgsLayerTreeModelLegendNode * > QgsLinearlyInterpolatedDiagramRenderer::l
     else
     {
       // manual classes need to get size scaled because the QgsSizeScaleTransformer is not used in diagrams :-(
-      Q_FOREACH ( const QgsDataDefinedSizeLegend::SizeClass &sc, ddSizeLegend.classes() )
+      const auto constClasses = ddSizeLegend.classes();
+      for ( const QgsDataDefinedSizeLegend::SizeClass &sc : constClasses )
       {
         double size = mDiagram->legendSize( sc.size, mSettings, mInterpolationSettings );
         sizeClasses << QgsDataDefinedSizeLegend::SizeClass( size, sc.label );
@@ -794,7 +797,8 @@ QList< QgsLayerTreeModelLegendNode * > QgsLinearlyInterpolatedDiagramRenderer::l
     }
     ddSizeLegend.setClasses( sizeClasses );
 
-    Q_FOREACH ( const QgsLegendSymbolItem &si, ddSizeLegend.legendSymbolList() )
+    const auto constLegendSymbolList = ddSizeLegend.legendSymbolList();
+    for ( const QgsLegendSymbolItem &si : constLegendSymbolList )
     {
       if ( si.dataDefinedSizeLegendSettings() )
         nodes << new QgsDataDefinedSizeLegendNode( nodeLayer, *si.dataDefinedSizeLegendSettings() );
diff --git a/src/core/qgsfeature.cpp b/src/core/qgsfeature.cpp
index e28ff53f4da..b7186bf609c 100644
--- a/src/core/qgsfeature.cpp
+++ b/src/core/qgsfeature.cpp
@@ -319,7 +319,8 @@ QDataStream &operator>>( QDataStream &in, QgsFeature &feature )
 uint qHash( const QgsFeature &key, uint seed )
 {
   uint hash = seed;
-  Q_FOREACH ( const QVariant &attr, key.attributes() )
+  const auto constAttributes = key.attributes();
+  for ( const QVariant &attr : constAttributes )
   {
     hash ^= qHash( attr.toString() );
   }
diff --git a/src/core/qgsinterval.cpp b/src/core/qgsinterval.cpp
index 120f14fe458..447e58b9898 100644
--- a/src/core/qgsinterval.cpp
+++ b/src/core/qgsinterval.cpp
@@ -81,7 +81,8 @@ QgsInterval QgsInterval::fromString( const QString &string )
     for ( ; it != map.constEnd(); ++it )
     {
       int duration = it.key();
-      Q_FOREACH ( const QString &name, it.value() )
+      const auto constValue = it.value();
+      for ( const QString &name : constValue )
       {
         if ( match.contains( name, Qt::CaseInsensitive ) )
         {
diff --git a/src/core/qgsjsonutils.cpp b/src/core/qgsjsonutils.cpp
index e03cfecf9fe..ff4bac83680 100644
--- a/src/core/qgsjsonutils.cpp
+++ b/src/core/qgsjsonutils.cpp
@@ -340,7 +340,8 @@ QVariantList QgsJsonUtils::parseArray( const QString &json, QVariant::Type type
     QgsLogger::warning( QStringLiteral( "Cannot parse json (%1) as array: %2" ).arg( error.errorString(), json ) );
     return result;
   }
-  Q_FOREACH ( const QJsonValue &cur, jsonDoc.array() )
+  const auto constArray = jsonDoc.array();
+  for ( const QJsonValue &cur : constArray )
   {
     QVariant curVariant = cur.toVariant();
     if ( curVariant.convert( type ) )
diff --git a/src/core/qgslegendrenderer.cpp b/src/core/qgslegendrenderer.cpp
index 4bd8f7c9cf6..9dac15e83e9 100644
--- a/src/core/qgslegendrenderer.cpp
+++ b/src/core/qgslegendrenderer.cpp
@@ -236,7 +236,8 @@ QList<QgsLegendRenderer::Atom> QgsLegendRenderer::createAtomList( QgsLayerTreeGr
 
   if ( !parentGroup ) return atoms;
 
-  Q_FOREACH ( QgsLayerTreeNode *node, parentGroup->children() )
+  const auto constChildren = parentGroup->children();
+  for ( QgsLayerTreeNode *node : constChildren )
   {
     if ( QgsLayerTree::isGroup( node ) )
     {
diff --git a/src/core/qgsmaphittest.cpp b/src/core/qgsmaphittest.cpp
index 3779aa5ad09..f31d564df04 100644
--- a/src/core/qgsmaphittest.cpp
+++ b/src/core/qgsmaphittest.cpp
@@ -56,7 +56,8 @@ void QgsMapHitTest::run()
   QgsRenderContext context = QgsRenderContext::fromMapSettings( mSettings );
   context.setPainter( &painter ); // we are not going to draw anything, but we still need a working painter
 
-  Q_FOREACH ( QgsMapLayer *layer, mSettings.layers() )
+  const auto constLayers = mSettings.layers();
+  for ( QgsMapLayer *layer : constLayers )
   {
     QgsVectorLayer *vl = qobject_cast<QgsVectorLayer *>( layer );
     if ( !vl || !vl->renderer() )
diff --git a/src/core/qgsmaplayer.cpp b/src/core/qgsmaplayer.cpp
index aca4f3893bc..0864a5d1e5f 100644
--- a/src/core/qgsmaplayer.cpp
+++ b/src/core/qgsmaplayer.cpp
@@ -110,7 +110,8 @@ void QgsMapLayer::clone( QgsMapLayer *layer ) const
 {
   layer->setBlendMode( blendMode() );
 
-  Q_FOREACH ( const QString &s, styleManager()->styles() )
+  const auto constStyles = styleManager()->styles();
+  for ( const QString &s : constStyles )
   {
     layer->styleManager()->addStyle( s, styleManager()->style( s ) );
   }
@@ -1830,7 +1831,8 @@ static QList<const QgsMapLayer *> _depOutEdges( const QgsMapLayer *vl, const Qgs
   }
   else
   {
-    Q_FOREACH ( const QgsMapLayerDependency &dep, vl->dependencies() )
+    const auto constDependencies = vl->dependencies();
+    for ( const QgsMapLayerDependency &dep : constDependencies )
     {
       if ( const QgsMapLayer *l = QgsProject::instance()->mapLayer( dep.layerId() ) )
         lst << l;
diff --git a/src/core/qgsmaplayerlegend.cpp b/src/core/qgsmaplayerlegend.cpp
index 14e9e1d8499..8dda0da876a 100644
--- a/src/core/qgsmaplayerlegend.cpp
+++ b/src/core/qgsmaplayerlegend.cpp
@@ -216,7 +216,8 @@ QList<QgsLayerTreeModelLegendNode *> QgsDefaultVectorLayerLegend::createLayerTre
     nodes.append( new QgsSimpleLegendNode( nodeLayer, r->legendClassificationAttribute() ) );
   }
 
-  Q_FOREACH ( const QgsLegendSymbolItem &i, r->legendSymbolItems() )
+  const auto constLegendSymbolItems = r->legendSymbolItems();
+  for ( const QgsLegendSymbolItem &i : constLegendSymbolItems )
   {
     if ( i.dataDefinedSizeLegendSettings() )
       nodes << new QgsDataDefinedSizeLegendNode( nodeLayer, *i.dataDefinedSizeLegendSettings() );
diff --git a/src/core/qgsmaprendererjob.cpp b/src/core/qgsmaprendererjob.cpp
index 46eaba33837..f5ce9dc9e5c 100644
--- a/src/core/qgsmaprendererjob.cpp
+++ b/src/core/qgsmaprendererjob.cpp
@@ -419,7 +419,8 @@ void QgsMapRendererJob::cleanupJobs( LayerRenderJobs &jobs )
 
     if ( job.renderer )
     {
-      Q_FOREACH ( const QString &message, job.renderer->errors() )
+      const auto constErrors = job.renderer->errors();
+      for ( const QString &message : constErrors )
         mErrors.append( Error( job.renderer->layerId(), message ) );
 
       delete job.renderer;
diff --git a/src/core/qgsmapsettingsutils.cpp b/src/core/qgsmapsettingsutils.cpp
index 53d65526eed..6ba20f9c99d 100644
--- a/src/core/qgsmapsettingsutils.cpp
+++ b/src/core/qgsmapsettingsutils.cpp
@@ -28,7 +28,8 @@ const QStringList QgsMapSettingsUtils::containsAdvancedEffects( const QgsMapSett
   QSet< QString > layers;
 
   QgsTextFormat layerFormat;
-  Q_FOREACH ( QgsMapLayer *layer, mapSettings.layers() )
+  const auto constLayers = mapSettings.layers();
+  for ( QgsMapLayer *layer : constLayers )
   {
     if ( layer )
     {
diff --git a/src/core/qgsmapthemecollection.cpp b/src/core/qgsmapthemecollection.cpp
index efadcb08431..23f1b6c467d 100644
--- a/src/core/qgsmapthemecollection.cpp
+++ b/src/core/qgsmapthemecollection.cpp
@@ -78,7 +78,8 @@ static QString _groupId( QgsLayerTreeNode *node )
 
 void QgsMapThemeCollection::createThemeFromCurrentState( QgsLayerTreeGroup *parent, QgsLayerTreeModel *model, QgsMapThemeCollection::MapThemeRecord &rec )
 {
-  Q_FOREACH ( QgsLayerTreeNode *node, parent->children() )
+  const auto constChildren = parent->children();
+  for ( QgsLayerTreeNode *node : constChildren )
   {
     if ( QgsLayerTree::isGroup( node ) )
     {
@@ -170,7 +171,8 @@ void QgsMapThemeCollection::applyThemeToLayer( QgsLayerTreeLayer *nodeLayer, Qgs
 
 void QgsMapThemeCollection::applyThemeToGroup( QgsLayerTreeGroup *parent, QgsLayerTreeModel *model, const QgsMapThemeCollection::MapThemeRecord &rec )
 {
-  Q_FOREACH ( QgsLayerTreeNode *node, parent->children() )
+  const auto constChildren = parent->children();
+  for ( QgsLayerTreeNode *node : constChildren )
   {
     if ( QgsLayerTree::isGroup( node ) )
     {
@@ -344,7 +346,8 @@ void QgsMapThemeCollection::applyMapThemeCheckedLegendNodesToLayer( const MapThe
 
   bool someNodesUnchecked = layerRec.usingLegendItems;
 
-  Q_FOREACH ( const QgsLegendSymbolItem &item, vlayer->renderer()->legendSymbolItems() )
+  const auto constLegendSymbolItems = vlayer->renderer()->legendSymbolItems();
+  for ( const QgsLegendSymbolItem &item : constLegendSymbolItems )
   {
     bool checked = renderer->legendSymbolItemChecked( item.ruleKey() );
     bool shouldBeChecked = someNodesUnchecked ? layerRec.checkedLegendItems.contains( item.ruleKey() ) : true;
diff --git a/src/core/qgsnetworkaccessmanager.cpp b/src/core/qgsnetworkaccessmanager.cpp
index 75149606f53..9134854c19a 100644
--- a/src/core/qgsnetworkaccessmanager.cpp
+++ b/src/core/qgsnetworkaccessmanager.cpp
@@ -58,7 +58,8 @@ class QgsNetworkProxyFactory : public QNetworkProxyFactory
       QgsNetworkAccessManager *nam = QgsNetworkAccessManager::instance();
 
       // iterate proxies factories and take first non empty list
-      Q_FOREACH ( QNetworkProxyFactory *f, nam->proxyFactories() )
+      const auto constProxyFactories = nam->proxyFactories();
+      for ( QNetworkProxyFactory *f : constProxyFactories )
       {
         QList<QNetworkProxy> systemproxies = f->systemProxyForQuery( query );
         if ( !systemproxies.isEmpty() )
@@ -75,7 +76,8 @@ class QgsNetworkProxyFactory : public QNetworkProxyFactory
 
       QString url = query.url().toString();
 
-      Q_FOREACH ( const QString &exclude, nam->excludeList() )
+      const auto constExcludeList = nam->excludeList();
+      for ( const QString &exclude : constExcludeList )
       {
         if ( !exclude.trimmed().isEmpty() && url.startsWith( exclude ) )
         {
diff --git a/src/core/qgsnetworkreplyparser.cpp b/src/core/qgsnetworkreplyparser.cpp
index 592ba3607e6..ec760bf3b44 100644
--- a/src/core/qgsnetworkreplyparser.cpp
+++ b/src/core/qgsnetworkreplyparser.cpp
@@ -38,7 +38,8 @@ QgsNetworkReplyParser::QgsNetworkReplyParser( QNetworkReply *reply )
   {
     // reply is not multipart, copy body and headers
     QMap<QByteArray, QByteArray> headers;
-    Q_FOREACH ( QByteArray h, mReply->rawHeaderList() )
+    const auto constRawHeaderList = mReply->rawHeaderList();
+    for ( QByteArray h : constRawHeaderList )
     {
       headers.insert( h, mReply->rawHeader( h ) );
     }
diff --git a/src/core/qgsobjectcustomproperties.cpp b/src/core/qgsobjectcustomproperties.cpp
index 6e7e401c50c..1f8a9890cf3 100644
--- a/src/core/qgsobjectcustomproperties.cpp
+++ b/src/core/qgsobjectcustomproperties.cpp
@@ -128,7 +128,8 @@ void QgsObjectCustomProperties::writeXml( QDomNode &parentNode, QDomDocument &do
     }
     else if ( it.value().canConvert<QStringList>() )
     {
-      Q_FOREACH ( const QString &value, it.value().toStringList() )
+      const auto constToStringList = it.value().toStringList();
+      for ( const QString &value : constToStringList )
       {
         QDomElement itemElement = doc.createElement( QStringLiteral( "value" ) );
         itemElement.appendChild( doc.createTextNode( value ) );
diff --git a/src/core/qgsogcutils.cpp b/src/core/qgsogcutils.cpp
index 426c27431f3..f8251ef81e1 100644
--- a/src/core/qgsogcutils.cpp
+++ b/src/core/qgsogcutils.cpp
@@ -2112,7 +2112,8 @@ QDomElement QgsOgcUtilsExprToFilter::expressionInOperatorToOgcFilter( const QgsE
   QDomElement orElem = mDoc.createElement( mFilterPrefix + ":Or" );
   QDomElement leftNode = expressionNodeToOgcFilter( node->node(), expression, context );
 
-  Q_FOREACH ( QgsExpressionNode *n, node->list()->list() )
+  const auto constList = node->list()->list();
+  for ( QgsExpressionNode *n : constList )
   {
     QDomElement listNode = expressionNodeToOgcFilter( n, expression, context );
     if ( !mErrorMessage.isEmpty() )
@@ -2317,7 +2318,8 @@ QDomElement QgsOgcUtilsExprToFilter::expressionFunctionToOgcFilter( const QgsExp
   // this is somehow wrong - we are just hoping that the other side supports the same functions as we do...
   QDomElement funcElem = mDoc.createElement( mFilterPrefix + ":Function" );
   funcElem.setAttribute( QStringLiteral( "name" ), fd->name() );
-  Q_FOREACH ( QgsExpressionNode *n, node->args()->list() )
+  const auto constList = node->args()->list();
+  for ( QgsExpressionNode *n : constList )
   {
     QDomElement childElem = expressionNodeToOgcFilter( n, expression, context );
     if ( !mErrorMessage.isEmpty() )
@@ -2563,7 +2565,8 @@ QDomElement QgsOgcUtilsSQLStatementToFilter::toOgcFilter( const QgsSQLStatement:
   QDomElement orElem = mDoc.createElement( mFilterPrefix + ":Or" );
   QDomElement leftNode = toOgcFilter( node->node() );
 
-  Q_FOREACH ( QgsSQLStatement::Node *n, node->list()->list() )
+  const auto constList = node->list()->list();
+  for ( QgsSQLStatement::Node *n : constList )
   {
     QDomElement listNode = toOgcFilter( n );
     if ( !mErrorMessage.isEmpty() )
@@ -2975,7 +2978,8 @@ QDomElement QgsOgcUtilsSQLStatementToFilter::toOgcFilter( const QgsSQLStatement:
   // Other function
   QDomElement funcElem = mDoc.createElement( mFilterPrefix + ":Function" );
   funcElem.setAttribute( QStringLiteral( "name" ), node->name() );
-  Q_FOREACH ( QgsSQLStatement::Node *n, node->args()->list() )
+  const auto constList = node->args()->list();
+  for ( QgsSQLStatement::Node *n : constList )
   {
     QDomElement childElem = toOgcFilter( n );
     if ( !mErrorMessage.isEmpty() )
@@ -2996,7 +3000,8 @@ QDomElement QgsOgcUtilsSQLStatementToFilter::toOgcFilter( const QgsSQLStatement:
   }
 
   QList<QDomElement> listElem;
-  Q_FOREACH ( const QString &columnName, node->usingColumns() )
+  const auto constUsingColumns = node->usingColumns();
+  for ( const QString &columnName : constUsingColumns )
   {
     QDomElement eqElem = mDoc.createElement( mFilterPrefix + ":PropertyIsEqualTo" );
     QDomElement propElem1 = mDoc.createElement( mFilterPrefix + ":" + mPropertyName );
@@ -3050,11 +3055,13 @@ QDomElement QgsOgcUtilsSQLStatementToFilter::toOgcFilter( const QgsSQLStatement:
   }
 
   // Register all table name aliases
-  Q_FOREACH ( QgsSQLStatement::NodeTableDef *table, node->tables() )
+  const auto constTables = node->tables();
+  for ( QgsSQLStatement::NodeTableDef *table : constTables )
   {
     visit( table );
   }
-  Q_FOREACH ( QgsSQLStatement::NodeJoin *join, node->joins() )
+  const auto constJoins = node->joins();
+  for ( QgsSQLStatement::NodeJoin *join : constJoins )
   {
     visit( join->tableDef() );
   }
@@ -3062,7 +3069,7 @@ QDomElement QgsOgcUtilsSQLStatementToFilter::toOgcFilter( const QgsSQLStatement:
   // Process JOIN conditions
   QList< QgsSQLStatement::NodeTableDef *> nodeTables = node->tables();
   QString leftTable = nodeTables.at( nodeTables.length() - 1 )->name();
-  Q_FOREACH ( QgsSQLStatement::NodeJoin *join, node->joins() )
+  for ( QgsSQLStatement::NodeJoin *join : constJoins )
   {
     QDomElement joinElem = toOgcFilter( join, leftTable );
     if ( !mErrorMessage.isEmpty() )
diff --git a/src/core/qgsproject.cpp b/src/core/qgsproject.cpp
index 1c9dee35af7..45dadca80da 100644
--- a/src/core/qgsproject.cpp
+++ b/src/core/qgsproject.cpp
@@ -1435,7 +1435,8 @@ bool QgsProject::readProjectFile( const QString &filename )
 void QgsProject::loadEmbeddedNodes( QgsLayerTreeGroup *group )
 {
 
-  Q_FOREACH ( QgsLayerTreeNode *child, group->children() )
+  const auto constChildren = group->children();
+  for ( QgsLayerTreeNode *child : constChildren )
   {
     if ( QgsLayerTree::isGroup( child ) )
     {
@@ -1449,7 +1450,8 @@ void QgsProject::loadEmbeddedNodes( QgsLayerTreeGroup *group )
         if ( newGroup )
         {
           QList<QgsLayerTreeNode *> clonedChildren;
-          Q_FOREACH ( QgsLayerTreeNode *newGroupChild, newGroup->children() )
+          const auto constChildren = newGroup->children();
+          for ( QgsLayerTreeNode *newGroupChild : constChildren )
             clonedChildren << newGroupChild->clone();
           delete newGroup;
 
@@ -1865,7 +1867,8 @@ bool QgsProject::writeProjectFile( const QString &filename )
   qgisNode.appendChild( projectLayersNode );
 
   QDomElement layerOrderNode = doc->createElement( QStringLiteral( "layerorder" ) );
-  Q_FOREACH ( QgsMapLayer *layer, mRootGroup->customLayerOrder() )
+  const auto constCustomLayerOrder = mRootGroup->customLayerOrder();
+  for ( QgsMapLayer *layer : constCustomLayerOrder )
   {
     QDomElement mapLayerElem = doc->createElement( QStringLiteral( "layer" ) );
     mapLayerElem.setAttribute( QStringLiteral( "id" ), layer->id() );
@@ -2393,7 +2396,8 @@ QgsLayerTreeGroup *QgsProject::createEmbeddedGroup( const QString &groupName, co
   mLayerTreeRegistryBridge->setEnabled( true );
 
   // consider the layers might be identify disabled in its project
-  Q_FOREACH ( const QString &layerId, newGroup->findLayerIds() )
+  const auto constFindLayerIds = newGroup->findLayerIds();
+  for ( const QString &layerId : constFindLayerIds )
   {
     QgsLayerTreeLayer *layer = newGroup->findLayer( layerId );
     if ( layer )
@@ -2408,7 +2412,8 @@ QgsLayerTreeGroup *QgsProject::createEmbeddedGroup( const QString &groupName, co
 
 void QgsProject::initializeEmbeddedSubtree( const QString &projectFilePath, QgsLayerTreeGroup *group )
 {
-  Q_FOREACH ( QgsLayerTreeNode *child, group->children() )
+  const auto constChildren = group->children();
+  for ( QgsLayerTreeNode *child : constChildren )
   {
     // all nodes in the subtree will have "embedded" custom property set
     child->setCustomProperty( QStringLiteral( "embedded" ), 1 );
diff --git a/src/core/qgsproviderregistry.cpp b/src/core/qgsproviderregistry.cpp
index c32e4350974..6a142123e02 100644
--- a/src/core/qgsproviderregistry.cpp
+++ b/src/core/qgsproviderregistry.cpp
@@ -125,7 +125,8 @@ void QgsProviderRegistry::init()
     fileRegexp.setPattern( filePattern );
   }
 
-  Q_FOREACH ( const QFileInfo &fi, mLibraryDirectory.entryInfoList() )
+  const auto constEntryInfoList = mLibraryDirectory.entryInfoList();
+  for ( const QFileInfo &fi : constEntryInfoList )
   {
     if ( !fileRegexp.isEmpty() )
     {
diff --git a/src/core/qgsrelationmanager.cpp b/src/core/qgsrelationmanager.cpp
index 6957faae757..eed084b5af1 100644
--- a/src/core/qgsrelationmanager.cpp
+++ b/src/core/qgsrelationmanager.cpp
@@ -126,7 +126,8 @@ QList<QgsRelation> QgsRelationManager::referencingRelations( const QgsVectorLaye
       if ( fieldIdx != -2 )
       {
         bool containsField = false;
-        Q_FOREACH ( const QgsRelation::FieldPair &fp, rel.fieldPairs() )
+        const auto constFieldPairs = rel.fieldPairs();
+        for ( const QgsRelation::FieldPair &fp : constFieldPairs )
         {
           if ( fieldIdx == layer->fields().lookupField( fp.referencingField() ) )
           {
diff --git a/src/core/qgssnappingconfig.cpp b/src/core/qgssnappingconfig.cpp
index e646d222205..ed03c16bb26 100644
--- a/src/core/qgssnappingconfig.cpp
+++ b/src/core/qgssnappingconfig.cpp
@@ -148,7 +148,8 @@ void QgsSnappingConfig::reset()
 
   // set advanced config
   mIndividualLayerSettings = QHash<QgsVectorLayer *, IndividualLayerSettings>();
-  Q_FOREACH ( QgsMapLayer *ml, mProject->mapLayers() )
+  const auto constMapLayers = mProject->mapLayers();
+  for ( QgsMapLayer *ml : constMapLayers )
   {
     QgsVectorLayer *vl = dynamic_cast<QgsVectorLayer *>( ml );
     if ( vl )
diff --git a/src/core/qgssnappingutils.cpp b/src/core/qgssnappingutils.cpp
index aea1bd43b5a..cd99ea655b2 100644
--- a/src/core/qgssnappingutils.cpp
+++ b/src/core/qgssnappingutils.cpp
@@ -124,7 +124,8 @@ static QgsPointLocator::Match _findClosestSegmentIntersection( const QgsPointXY
   QList<QgsPointXY> newPoints;
   if ( g.wkbType() == QgsWkbTypes::LineString )
   {
-    Q_FOREACH ( const QgsPointXY &p, g.asPolyline() )
+    const auto constAsPolyline = g.asPolyline();
+    for ( const QgsPointXY &p : constAsPolyline )
     {
       if ( !endpoints.contains( p ) )
         newPoints << p;
@@ -132,7 +133,8 @@ static QgsPointLocator::Match _findClosestSegmentIntersection( const QgsPointXY
   }
   if ( g.wkbType() == QgsWkbTypes::MultiLineString )
   {
-    Q_FOREACH ( const QgsPolylineXY &pl, g.asMultiPolyline() )
+    const auto constAsMultiPolyline = g.asMultiPolyline();
+    for ( const QgsPolylineXY &pl : constAsMultiPolyline )
     {
       const auto constPl = pl;
       for ( const QgsPointXY &p : constPl )
@@ -306,7 +308,8 @@ QgsPointLocator::Match QgsSnappingUtils::snapToMap( const QgsPointXY &pointMap,
     QgsRectangle aoi = _areaOfInterest( pointMap, tolerance );
 
     QList<LayerAndAreaOfInterest> layers;
-    Q_FOREACH ( QgsMapLayer *layer, mMapSettings.layers() )
+    const auto constLayers = mMapSettings.layers();
+    for ( QgsMapLayer *layer : constLayers )
       if ( QgsVectorLayer *vl = qobject_cast<QgsVectorLayer *>( layer ) )
         layers << qMakePair( vl, aoi );
     prepareIndex( layers );
@@ -314,8 +317,7 @@ QgsPointLocator::Match QgsSnappingUtils::snapToMap( const QgsPointXY &pointMap,
     QgsPointLocator::MatchList edges; // for snap on intersection
     QgsPointLocator::Match bestMatch;
 
-    const auto constLayers = layers;
-    for ( const LayerAndAreaOfInterest &entry : constLayers )
+    for ( const LayerAndAreaOfInterest &entry : qgis::as_const( layers ) )
     {
       QgsVectorLayer *vl = entry.first;
       if ( QgsPointLocator *loc = locatorForLayerUsingStrategy( vl, pointMap, tolerance ) )
@@ -525,7 +527,8 @@ QString QgsSnappingUtils::dump()
   }
   else if ( mSnappingConfig.mode() == QgsSnappingConfig::AllLayers )
   {
-    Q_FOREACH ( QgsMapLayer *layer, mMapSettings.layers() )
+    const auto constLayers = mMapSettings.layers();
+    for ( QgsMapLayer *layer : constLayers )
     {
       if ( QgsVectorLayer *vl = qobject_cast<QgsVectorLayer *>( layer ) )
         layers << LayerConfig( vl, _snappingTypeToPointLocatorType( mSnappingConfig.type() ), mSnappingConfig.tolerance(), mSnappingConfig.units() );
diff --git a/src/core/qgssqlexpressioncompiler.cpp b/src/core/qgssqlexpressioncompiler.cpp
index 39854eb7960..65f408e6bbb 100644
--- a/src/core/qgssqlexpressioncompiler.cpp
+++ b/src/core/qgssqlexpressioncompiler.cpp
@@ -340,7 +340,8 @@ QgsSqlExpressionCompiler::Result QgsSqlExpressionCompiler::compileNode( const Qg
       QStringList list;
 
       Result inResult = Complete;
-      Q_FOREACH ( const QgsExpressionNode *ln, n->list()->list() )
+      const auto constList = n->list()->list();
+      for ( const QgsExpressionNode *ln : constList )
       {
         QString s;
         Result r = compileNode( ln, s );
@@ -377,7 +378,8 @@ QgsSqlExpressionCompiler::Result QgsSqlExpressionCompiler::compileNode( const Qg
       // compile arguments
       QStringList args;
       Result inResult = Complete;
-      Q_FOREACH ( const QgsExpressionNode *ln, n->args()->list() )
+      const auto constList = n->args()->list();
+      for ( const QgsExpressionNode *ln : constList )
       {
         QString s;
         Result r = compileNode( ln, s );
diff --git a/src/core/qgssqlstatement.cpp b/src/core/qgssqlstatement.cpp
index c2154d73bf3..e6eba72fcaa 100644
--- a/src/core/qgssqlstatement.cpp
+++ b/src/core/qgssqlstatement.cpp
@@ -160,22 +160,26 @@ const QgsSQLStatement::Node *QgsSQLStatement::rootNode() const
 
 void QgsSQLStatement::RecursiveVisitor::visit( const QgsSQLStatement::NodeSelect &n )
 {
-  Q_FOREACH ( QgsSQLStatement::NodeTableDef *table, n.tables() )
+  const auto constTables = n.tables();
+  for ( QgsSQLStatement::NodeTableDef *table : constTables )
   {
     table->accept( *this );
   }
-  Q_FOREACH ( QgsSQLStatement::NodeSelectedColumn *column, n.columns() )
+  const auto constColumns = n.columns();
+  for ( QgsSQLStatement::NodeSelectedColumn *column : constColumns )
   {
     column->accept( *this );
   }
-  Q_FOREACH ( QgsSQLStatement::NodeJoin *join, n.joins() )
+  const auto constJoins = n.joins();
+  for ( QgsSQLStatement::NodeJoin *join : constJoins )
   {
     join->accept( *this );
   }
   QgsSQLStatement::Node *where = n.where();
   if ( where )
     where->accept( *this );
-  Q_FOREACH ( QgsSQLStatement::NodeColumnSorted *column, n.orderBy() )
+  const auto constOrderBy = n.orderBy();
+  for ( QgsSQLStatement::NodeColumnSorted *column : constOrderBy )
   {
     column->accept( *this );
   }
diff --git a/src/core/qgstracer.cpp b/src/core/qgstracer.cpp
index 7fc57de5924..50f22079023 100644
--- a/src/core/qgstracer.cpp
+++ b/src/core/qgstracer.cpp
@@ -434,22 +434,31 @@ void extractLinework( const QgsGeometry &g, QgsMultiPolylineXY &mpl )
       break;
 
     case QgsWkbTypes::Polygon:
-      Q_FOREACH ( const QgsPolylineXY &ring, geom.asPolygon() )
+    {
+      const auto polygon = geom.asPolygon();
+      for ( const QgsPolylineXY &ring : polygon )
         mpl << ring;
-      break;
+    }
+    break;
 
     case QgsWkbTypes::MultiLineString:
-      Q_FOREACH ( const QgsPolylineXY &linestring, geom.asMultiPolyline() )
+    {
+      const auto multiPolyline = geom.asMultiPolyline();
+      for ( const QgsPolylineXY &linestring : multiPolyline )
         mpl << linestring;
-      break;
+    }
+    break;
 
     case QgsWkbTypes::MultiPolygon:
-      Q_FOREACH ( const QgsPolygonXY &polygon, geom.asMultiPolygon() )
+    {
+      const auto multiPolygon = geom.asMultiPolygon();
+      for ( const QgsPolygonXY &polygon : multiPolygon )
       {
         for ( const QgsPolylineXY &ring : polygon )
           mpl << ring;
       }
-      break;
+    }
+    break;
 
     default:
       break;  // unknown type - do nothing
diff --git a/src/core/qgsvectorlayer.cpp b/src/core/qgsvectorlayer.cpp
index fa4ee2e3bbc..a41c80eb68b 100644
--- a/src/core/qgsvectorlayer.cpp
+++ b/src/core/qgsvectorlayer.cpp
@@ -233,7 +233,8 @@ QgsVectorLayer *QgsVectorLayer::clone() const
   layer->setOpacity( opacity() );
   layer->setReadExtentFromXml( readExtentFromXml() );
 
-  Q_FOREACH ( const QgsAction &action, actions()->actions() )
+  const auto constActions = actions()->actions();
+  for ( const QgsAction &action : constActions )
   {
     layer->actions()->addAction( action );
   }
diff --git a/src/core/qgsvectorlayercache.cpp b/src/core/qgsvectorlayercache.cpp
index 5264ece4684..3b9ecd0f26c 100644
--- a/src/core/qgsvectorlayercache.cpp
+++ b/src/core/qgsvectorlayercache.cpp
@@ -243,7 +243,8 @@ void QgsVectorLayerCache::onJoinAttributeValueChanged( QgsFeatureId fid, int fie
 {
   const QgsVectorLayer *joinLayer = qobject_cast<const QgsVectorLayer *>( sender() );
 
-  Q_FOREACH ( const QgsVectorLayerJoinInfo &info, mLayer->vectorJoins() )
+  const auto constVectorJoins = mLayer->vectorJoins();
+  for ( const QgsVectorLayerJoinInfo &info : constVectorJoins )
   {
     if ( joinLayer == info.joinLayer() )
     {
@@ -455,7 +456,8 @@ bool QgsVectorLayerCache::checkInformationCovered( const QgsFeatureRequest &feat
 
 void QgsVectorLayerCache::connectJoinedLayers() const
 {
-  Q_FOREACH ( const QgsVectorLayerJoinInfo &info, mLayer->vectorJoins() )
+  const auto constVectorJoins = mLayer->vectorJoins();
+  for ( const QgsVectorLayerJoinInfo &info : constVectorJoins )
   {
     const QgsVectorLayer *vl = info.joinLayer();
     if ( vl )
diff --git a/src/core/qgsvectorlayereditbuffer.cpp b/src/core/qgsvectorlayereditbuffer.cpp
index 3acab86d891..9c9265223d6 100644
--- a/src/core/qgsvectorlayereditbuffer.cpp
+++ b/src/core/qgsvectorlayereditbuffer.cpp
@@ -549,10 +549,12 @@ bool QgsVectorLayerEditBuffer::commitChanges( QStringList &commitErrors )
           commitErrors << tr( "ERROR: %n attribute value change(s) not applied.", "not changed attribute values count", mChangedAttributeValues.size() );
 #if 0
           QString list = "ERROR: pending changes:";
-          Q_FOREACH ( QgsFeatureId id, mChangedAttributeValues.keys() )
+          const auto constKeys = mChangedAttributeValues.keys();
+          for ( QgsFeatureId id : constKeys )
           {
             list.append( "\n  " + FID_TO_STRING( id ) + '[' );
-            Q_FOREACH ( int idx, mChangedAttributeValues[ id ].keys() )
+            const auto constKeys = mChangedAttributeValues[ id ].keys();
+            for ( int idx : constKeys )
             {
               list.append( QString( " %1:%2" ).arg( L->fields().at( idx ).name() ).arg( mChangedAttributeValues[id][idx].toString() ) );
             }
@@ -680,7 +682,8 @@ bool QgsVectorLayerEditBuffer::commitChanges( QStringList &commitErrors )
   if ( !success && provider->hasErrors() )
   {
     commitErrors << tr( "\n  Provider errors:" );
-    Q_FOREACH ( QString e, provider->errors() )
+    const auto constErrors = provider->errors();
+    for ( QString e : constErrors )
     {
       commitErrors << "    " + e.replace( '\n', QLatin1String( "\n    " ) );
     }
diff --git a/src/core/qgsvectorlayerfeatureiterator.cpp b/src/core/qgsvectorlayerfeatureiterator.cpp
index ebac783bc5c..d3833c4e1cf 100644
--- a/src/core/qgsvectorlayerfeatureiterator.cpp
+++ b/src/core/qgsvectorlayerfeatureiterator.cpp
@@ -203,7 +203,8 @@ QgsVectorLayerFeatureIterator::QgsVectorLayerFeatureIterator( QgsVectorLayerFeat
   if ( mProviderRequest.filterType() == QgsFeatureRequest::FilterExpression )
   {
     const bool needsGeom = mProviderRequest.filterExpression()->needsGeometry();
-    Q_FOREACH ( const QString &field, mProviderRequest.filterExpression()->referencedColumns() )
+    const auto constReferencedColumns = mProviderRequest.filterExpression()->referencedColumns();
+    for ( const QString &field : constReferencedColumns )
     {
       int idx = source->mFields.lookupField( field );
 
@@ -628,7 +629,7 @@ void QgsVectorLayerFeatureIterator::prepareExpression( int fieldIdx )
   const QList<QgsExpressionFieldBuffer::ExpressionField> &exps = mSource->mExpressionFieldBuffer->expressions();
 
   int oi = mSource->mFields.fieldOriginIndex( fieldIdx );
-  QgsExpression *exp = new QgsExpression( exps[oi].cachedExpression );
+  std::unique_ptr<QgsExpression> exp = qgis::make_unique<QgsExpression>( exps[oi].cachedExpression );
 
   QgsDistanceArea da;
   da.setSourceCrs( mSource->mCrs, QgsProject::instance()->transformContext() );
@@ -638,18 +639,18 @@ void QgsVectorLayerFeatureIterator::prepareExpression( int fieldIdx )
   exp->setAreaUnits( QgsProject::instance()->areaUnits() );
 
   exp->prepare( mExpressionContext.get() );
-  Q_FOREACH ( const QString &col, exp->referencedColumns() )
+  const auto referencedColumns = exp->referencedColumns();
+  for ( const QString &col : referencedColumns )
   {
     if ( mSource->fields().lookupField( col ) == fieldIdx )
     {
       // circular reference - expression depends on column itself
-      delete exp;
       return;
     }
   }
-  mExpressionFieldInfo.insert( fieldIdx, exp );
+  mExpressionFieldInfo.insert( fieldIdx, exp.release() );
 
-  Q_FOREACH ( const QString &col, exp->referencedColumns() )
+  for ( const QString &col : referencedColumns )
   {
     int dependentFieldIdx = mSource->mFields.lookupField( col );
     if ( mRequest.flags() & QgsFeatureRequest::SubsetOfAttributes )
diff --git a/src/core/qgsvectorlayerjoinbuffer.cpp b/src/core/qgsvectorlayerjoinbuffer.cpp
index abf6c04b117..372056e1b7a 100644
--- a/src/core/qgsvectorlayerjoinbuffer.cpp
+++ b/src/core/qgsvectorlayerjoinbuffer.cpp
@@ -33,7 +33,8 @@ QgsVectorLayerJoinBuffer::QgsVectorLayerJoinBuffer( QgsVectorLayer *layer )
 static QList<QgsVectorLayer *> _outEdges( QgsVectorLayer *vl )
 {
   QList<QgsVectorLayer *> lst;
-  Q_FOREACH ( const QgsVectorLayerJoinInfo &info, vl->vectorJoins() )
+  const auto constVectorJoins = vl->vectorJoins();
+  for ( const QgsVectorLayerJoinInfo &info : constVectorJoins )
   {
     if ( QgsVectorLayer *joinVl = info.joinLayer() )
       lst << joinVl;
diff --git a/src/core/qgsvirtuallayerdefinitionutils.cpp b/src/core/qgsvirtuallayerdefinitionutils.cpp
index e59bd212120..3e6b43f2061 100644
--- a/src/core/qgsvirtuallayerdefinitionutils.cpp
+++ b/src/core/qgsvirtuallayerdefinitionutils.cpp
@@ -59,7 +59,8 @@ QgsVirtualLayerDefinition QgsVirtualLayerDefinitionUtils::fromJoinedLayer( QgsVe
   }
 
   int joinIdx = 0;
-  Q_FOREACH ( const QgsVectorLayerJoinInfo &join, layer->vectorJoins() )
+  const auto constVectorJoins = layer->vectorJoins();
+  for ( const QgsVectorLayerJoinInfo &join : constVectorJoins )
   {
     QString joinName = QStringLiteral( "j%1" ).arg( ++joinIdx );
     QgsVectorLayer *joinedLayer = join.joinLayer();
diff --git a/src/core/symbology/qgscptcityarchive.cpp b/src/core/symbology/qgscptcityarchive.cpp
index 581e3ab2061..cc365ce685e 100644
--- a/src/core/symbology/qgscptcityarchive.cpp
+++ b/src/core/symbology/qgscptcityarchive.cpp
@@ -1504,10 +1504,11 @@ QModelIndex QgsCptCityBrowserModel::findPath( const QString &path )
       // if we are using a selection collection, search for target in the mapping in this group
       if ( item->type() == QgsCptCityDataItem::Selection )
       {
-        const QgsCptCitySelectionItem *selItem = dynamic_cast<const QgsCptCitySelectionItem *>( item );
+        const QgsCptCitySelectionItem *selItem = qobject_cast<const QgsCptCitySelectionItem *>( item );
         if ( selItem )
         {
-          Q_FOREACH ( QString childPath, selItem->selectionsList() )
+          const auto constSelectionsList = selItem->selectionsList();
+          for ( QString childPath : constSelectionsList )
           {
             if ( childPath.endsWith( '/' ) )
               childPath.chop( 1 );
diff --git a/src/core/symbology/qgsrulebasedrenderer.cpp b/src/core/symbology/qgsrulebasedrenderer.cpp
index 812dcce5439..fbd47c78ec9 100644
--- a/src/core/symbology/qgsrulebasedrenderer.cpp
+++ b/src/core/symbology/qgsrulebasedrenderer.cpp
@@ -1163,7 +1163,8 @@ void QgsRuleBasedRenderer::refineRuleCategories( QgsRuleBasedRenderer::Rule *ini
     attr = QgsExpression::quotedColumnRef( attr );
   }
 
-  Q_FOREACH ( const QgsRendererCategory &cat, r->categories() )
+  const auto constCategories = r->categories();
+  for ( const QgsRendererCategory &cat : constCategories )
   {
     QString value;
     // not quoting numbers saves a type cast
@@ -1199,7 +1200,8 @@ void QgsRuleBasedRenderer::refineRuleRanges( QgsRuleBasedRenderer::Rule *initial
   }
 
   bool firstRange = true;
-  Q_FOREACH ( const QgsRendererRange &rng, r->ranges() )
+  const auto constRanges = r->ranges();
+  for ( const QgsRendererRange &rng : constRanges )
   {
     // due to the loss of precision in double->string conversion we may miss out values at the limit of the range
     // TODO: have a possibility to construct expressions directly as a parse tree to avoid loss of precision