diff --git a/python/core/geometry/qgsgeometry.sip b/python/core/geometry/qgsgeometry.sip
index c819c70c623..2dce2474e33 100644
--- a/python/core/geometry/qgsgeometry.sip
+++ b/python/core/geometry/qgsgeometry.sip
@@ -532,7 +532,7 @@ class QgsGeometry
       public:
         Error();
         Error( QString m );
-        Error( QString m, QgsPoint p );
+        Error( QString m, const QgsPoint& p );
 
         QString what();
         QgsPoint where();
diff --git a/python/core/qgslegendsettings.sip b/python/core/qgslegendsettings.sip
index fddbfa5dfac..7aa3e5f5193 100644
--- a/python/core/qgslegendsettings.sip
+++ b/python/core/qgslegendsettings.sip
@@ -47,10 +47,10 @@ class QgsLegendSettings
     int columnCount() const;
     void setColumnCount( int c );
 
-    int splitLayer() const;
+    bool splitLayer() const;
     void setSplitLayer( bool s );
 
-    int equalColumnWidth() const;
+    bool equalColumnWidth() const;
     void setEqualColumnWidth( bool s );
 
     QColor fontColor() const;
diff --git a/python/core/qgsvectorlayer.sip b/python/core/qgsvectorlayer.sip
index e515ebeaca7..6ad9e64c0a5 100644
--- a/python/core/qgsvectorlayer.sip
+++ b/python/core/qgsvectorlayer.sip
@@ -190,7 +190,7 @@ class QgsVectorLayer : QgsMapLayer
     struct RangeData
     {
       RangeData();
-      RangeData( QVariant theMin, QVariant theMax, QVariant theStep );
+      RangeData( const QVariant& theMin, const QVariant& theMax, const QVariant& theStep );
 
       QVariant mMin;
       QVariant mMax;
diff --git a/python/core/symbology-ng/qgsheatmaprenderer.sip b/python/core/symbology-ng/qgsheatmaprenderer.sip
index 170036a686e..a15b993213f 100644
--- a/python/core/symbology-ng/qgsheatmaprenderer.sip
+++ b/python/core/symbology-ng/qgsheatmaprenderer.sip
@@ -43,7 +43,8 @@ class QgsHeatmapRenderer : QgsFeatureRendererV2
      * @see setInvertRamp
      * @see colorRamp
     */
-    double invertRamp() const;
+    bool invertRamp() const;
+
     /** Sets whether the ramp is inverted
      * @param invert set to true to invert color ramp
      * @see invertRamp
diff --git a/python/core/symbology-ng/qgsrendererv2.sip b/python/core/symbology-ng/qgsrendererv2.sip
index 5996b33ce51..e4b6d8ec73f 100644
--- a/python/core/symbology-ng/qgsrendererv2.sip
+++ b/python/core/symbology-ng/qgsrendererv2.sip
@@ -274,7 +274,7 @@ class QgsFeatureRendererV2
                                   bool drawVertexMarker );
 
     //! render editing vertex marker at specified point
-    void renderVertexMarker( QPointF& pt, QgsRenderContext& context );
+    void renderVertexMarker( const QPointF& pt, QgsRenderContext& context );
     //! render editing vertex marker for a polyline
     void renderVertexMarkerPolyline( QPolygonF& pts, QgsRenderContext& context );
     //! render editing vertex marker for a polygon
diff --git a/python/core/symbology-ng/qgssymbollayerv2utils.sip b/python/core/symbology-ng/qgssymbollayerv2utils.sip
index fea6385091e..3a8796bcb69 100644
--- a/python/core/symbology-ng/qgssymbollayerv2utils.sip
+++ b/python/core/symbology-ng/qgssymbollayerv2utils.sip
@@ -169,7 +169,7 @@ class QgsSymbolLayerV2Utils
 
 
     static void labelTextToSld( QDomDocument &doc, QDomElement &element, QString label,
-                                QFont font, QColor color = QColor(), double size = -1 );
+                                const QFont& font, QColor color = QColor(), double size = -1 );
 
     /** Create ogr feature style string for pen */
     static QString ogrFeatureStylePen( double width, double mmScaleFactor, double mapUnitsScaleFactor, const QColor& c,
diff --git a/python/core/symbology-ng/qgssymbolv2.sip b/python/core/symbology-ng/qgssymbolv2.sip
index 8e6d78e6030..fae20dad91e 100644
--- a/python/core/symbology-ng/qgssymbolv2.sip
+++ b/python/core/symbology-ng/qgssymbolv2.sip
@@ -156,7 +156,7 @@ class QgsSymbolV2
      * @note added in QGIS 2.9
      * @see setClipFeaturesToExtent
      */
-    double clipFeaturesToExtent() const;
+    bool clipFeaturesToExtent() const;
 
     QSet<QString> usedAttributes() const;
 
diff --git a/src/analysis/raster/qgsrelief.cpp b/src/analysis/raster/qgsrelief.cpp
index 53a3abd0f07..efc496031c2 100644
--- a/src/analysis/raster/qgsrelief.cpp
+++ b/src/analysis/raster/qgsrelief.cpp
@@ -674,6 +674,7 @@ QList< QgsRelief::ReliefColor > QgsRelief::calculateOptimizedReliefClasses()
   colorList.push_back( QColor( 255, 133, 92 ) );
   colorList.push_back( QColor( 204, 204, 204 ) );
 
+  resultList.reserve( classBreaks.size() );
   for ( int i = 1; i < classBreaks.size(); ++i )
   {
     double minElevation = minMax[0] + classBreaks[i - 1] * frequencyClassRange;
diff --git a/src/analysis/vector/qgstransectsample.cpp b/src/analysis/vector/qgstransectsample.cpp
index 689ca8a48c2..41b08cedfe4 100644
--- a/src/analysis/vector/qgstransectsample.cpp
+++ b/src/analysis/vector/qgstransectsample.cpp
@@ -614,6 +614,7 @@ QgsGeometry* QgsTransectSample::clipBufferLine( const QgsGeometry* stratumGeom,
       }
 
       int size = bufferPolygon.size();
+      mpl.reserve( size );
       for ( int j = 0; j < size; ++j )
       {
         mpl.append( bufferPolygon[j] );
diff --git a/src/app/qgsattributetabledialog.cpp b/src/app/qgsattributetabledialog.cpp
index 20cb754293a..e67eb681c62 100644
--- a/src/app/qgsattributetabledialog.cpp
+++ b/src/app/qgsattributetabledialog.cpp
@@ -329,7 +329,7 @@ void QgsAttributeTableDialog::columnBoxInit()
 
   QList<QgsField> fields = mLayer->fields().toList();
 
-  Q_FOREACH ( const QgsField field, fields )
+  Q_FOREACH ( const QgsField& field, fields )
   {
     int idx = mLayer->fieldNameIndex( field.name() );
     if ( idx < 0 )
diff --git a/src/app/qgsconfigureshortcutsdialog.cpp b/src/app/qgsconfigureshortcutsdialog.cpp
index da7174a6a12..5b0c934fc9f 100644
--- a/src/app/qgsconfigureshortcutsdialog.cpp
+++ b/src/app/qgsconfigureshortcutsdialog.cpp
@@ -75,6 +75,7 @@ void QgsConfigureShortcutsDialog::populateActions()
   QList<QAction*> actions = QgsShortcutsManager::instance()->listActions();
 
   QList<QTreeWidgetItem *> items;
+  items.reserve( actions.count() );
   for ( int i = 0; i < actions.count(); ++i )
   {
     QString actionText = actions[i]->text();
diff --git a/src/app/qgsdiagramproperties.cpp b/src/app/qgsdiagramproperties.cpp
index 794de1e70ac..a78a5670013 100644
--- a/src/app/qgsdiagramproperties.cpp
+++ b/src/app/qgsdiagramproperties.cpp
@@ -683,6 +683,9 @@ void QgsDiagramProperties::apply()
   QList<QColor> categoryColors;
   QList<QString> categoryAttributes;
   QList<QString> categoryLabels;
+  categoryColors.reserve( mDiagramAttributesTreeWidget->topLevelItemCount() );
+  categoryAttributes.reserve( mDiagramAttributesTreeWidget->topLevelItemCount() );
+  categoryLabels.reserve( mDiagramAttributesTreeWidget->topLevelItemCount() );
   for ( int i = 0; i < mDiagramAttributesTreeWidget->topLevelItemCount(); ++i )
   {
     QColor color = mDiagramAttributesTreeWidget->topLevelItem( i )->background( 1 ).color();
diff --git a/src/app/qgslabeldialog.cpp b/src/app/qgslabeldialog.cpp
index 5478b9c83ee..43d668ce177 100644
--- a/src/app/qgslabeldialog.cpp
+++ b/src/app/qgslabeldialog.cpp
@@ -61,6 +61,7 @@ void QgsLabelDialog::init()
   const QgsFields& myFields = mLabel->fields();
   QStringList myFieldStringList;
   myFieldStringList.append( "" );
+  myFieldStringList.reserve( 1 + myFields.count() );
   for ( int i = 0; i < myFields.count(); ++i )
   {
     myFieldStringList.append( myFields[i].name() );
diff --git a/src/app/qgsmaptooladdfeature.cpp b/src/app/qgsmaptooladdfeature.cpp
index ccab8aace68..a09738ef9a9 100644
--- a/src/app/qgsmaptooladdfeature.cpp
+++ b/src/app/qgsmaptooladdfeature.cpp
@@ -223,7 +223,7 @@ void QgsMapToolAddFeature::cadCanvasReleaseEvent( QgsMapMouseEvent* e )
       QgsCurveV2* curveToAdd = 0;
       if ( hasCurvedSegments && providerSupportsCurvedSegments )
       {
-        curveToAdd = dynamic_cast<QgsCurveV2*>( captureCurve()->clone() );
+        curveToAdd = captureCurve()->clone();
       }
       else
       {
diff --git a/src/app/qgsmaptooladdpart.cpp b/src/app/qgsmaptooladdpart.cpp
index d46ef4a5c59..2973986a4cd 100644
--- a/src/app/qgsmaptooladdpart.cpp
+++ b/src/app/qgsmaptooladdpart.cpp
@@ -134,7 +134,7 @@ void QgsMapToolAddPart::cadCanvasReleaseEvent( QgsMapMouseEvent * e )
       QgsCurveV2* curveToAdd = 0;
       if ( hasCurvedSegments && providerSupportsCurvedSegments )
       {
-        curveToAdd = dynamic_cast<QgsCurveV2*>( captureCurve()->clone() );
+        curveToAdd = captureCurve()->clone();
       }
       else
       {
diff --git a/src/app/qgsmaptooladdring.cpp b/src/app/qgsmaptooladdring.cpp
index bcee74c99ef..0cd376d7884 100644
--- a/src/app/qgsmaptooladdring.cpp
+++ b/src/app/qgsmaptooladdring.cpp
@@ -92,7 +92,7 @@ void QgsMapToolAddRing::cadCanvasReleaseEvent( QgsMapMouseEvent * e )
     QgsCurveV2* curveToAdd = 0;
     if ( hasCurvedSegments && providerSupportsCurvedSegments )
     {
-      curveToAdd = dynamic_cast<QgsCurveV2*>( captureCurve()->clone() );
+      curveToAdd = captureCurve()->clone();
     }
     else
     {
diff --git a/src/app/qgsmergeattributesdialog.cpp b/src/app/qgsmergeattributesdialog.cpp
index 6e5aac20e77..acc56c439ba 100644
--- a/src/app/qgsmergeattributesdialog.cpp
+++ b/src/app/qgsmergeattributesdialog.cpp
@@ -449,6 +449,7 @@ QVariant QgsMergeAttributesDialog::sumAttribute( int col )
 QVariant QgsMergeAttributesDialog::concatenationAttribute( int col )
 {
   QStringList concatString;
+  concatString.reserve( mFeatureList.size() );
   for ( int i = 0; i < mFeatureList.size(); ++i )
   {
     concatString << mTableWidget->item( i + 1, col )->text();
diff --git a/src/app/qgsoptions.cpp b/src/app/qgsoptions.cpp
index 7bdadcec3f6..4410550f81c 100644
--- a/src/app/qgsoptions.cpp
+++ b/src/app/qgsoptions.cpp
@@ -1911,6 +1911,7 @@ void QgsOptions::on_pbnExportScales_clicked()
   }
 
   QStringList myScales;
+  myScales.reserve( mListGlobalScales->count() );
   for ( int i = 0; i < mListGlobalScales->count(); ++i )
   {
     myScales.append( mListGlobalScales->item( i )->text() );
diff --git a/src/app/qgsprojectproperties.cpp b/src/app/qgsprojectproperties.cpp
index 96dc4aaa6ae..bb41306955e 100644
--- a/src/app/qgsprojectproperties.cpp
+++ b/src/app/qgsprojectproperties.cpp
@@ -686,6 +686,7 @@ void QgsProjectProperties::apply()
 
   //save project scales
   QStringList myScales;
+  myScales.reserve( lstScales->count() );
   for ( int i = 0; i < lstScales->count(); ++i )
   {
     myScales.append( lstScales->item( i )->text() );
diff --git a/src/core/auth/qgsauthcertutils.cpp b/src/core/auth/qgsauthcertutils.cpp
index bf51d30a2d3..8159106d202 100644
--- a/src/core/auth/qgsauthcertutils.cpp
+++ b/src/core/auth/qgsauthcertutils.cpp
@@ -49,7 +49,7 @@ QString QgsAuthCertUtils::getSslProtocolName( QSsl::SslProtocol protocol )
 QMap<QString, QSslCertificate> QgsAuthCertUtils::mapDigestToCerts( QList<QSslCertificate> certs )
 {
   QMap<QString, QSslCertificate> digestmap;
-  Q_FOREACH ( QSslCertificate cert, certs )
+  Q_FOREACH ( const QSslCertificate& cert, certs )
   {
     digestmap.insert( shaHexForCert( cert ), cert );
   }
@@ -59,7 +59,7 @@ QMap<QString, QSslCertificate> QgsAuthCertUtils::mapDigestToCerts( QList<QSslCer
 QMap<QString, QList<QSslCertificate> > QgsAuthCertUtils::certsGroupedByOrg( QList<QSslCertificate> certs )
 {
   QMap< QString, QList<QSslCertificate> > orgcerts;
-  Q_FOREACH ( QSslCertificate cert, certs )
+  Q_FOREACH ( const QSslCertificate& cert, certs )
   {
     QString org( cert.subjectInfo( QSslCertificate::Organization ) );
     if ( org.isEmpty() )
@@ -73,7 +73,7 @@ QMap<QString, QList<QSslCertificate> > QgsAuthCertUtils::certsGroupedByOrg( QLis
 QMap<QString, QgsAuthConfigSslServer> QgsAuthCertUtils::mapDigestToSslConfigs( QList<QgsAuthConfigSslServer> configs )
 {
   QMap<QString, QgsAuthConfigSslServer> digestmap;
-  Q_FOREACH ( QgsAuthConfigSslServer config, configs )
+  Q_FOREACH ( const QgsAuthConfigSslServer& config, configs )
   {
     digestmap.insert( shaHexForCert( config.sslCertificate() ), config );
   }
@@ -83,7 +83,7 @@ QMap<QString, QgsAuthConfigSslServer> QgsAuthCertUtils::mapDigestToSslConfigs( Q
 QMap<QString, QList<QgsAuthConfigSslServer> > QgsAuthCertUtils::sslConfigsGroupedByOrg( QList<QgsAuthConfigSslServer> configs )
 {
   QMap< QString, QList<QgsAuthConfigSslServer> > orgconfigs;
-  Q_FOREACH ( QgsAuthConfigSslServer config, configs )
+  Q_FOREACH ( const QgsAuthConfigSslServer& config, configs )
   {
     QString org( config.sslCertificate().subjectInfo( QSslCertificate::Organization ) );
     if ( org.isEmpty() )
@@ -371,6 +371,7 @@ QString QgsAuthCertUtils::getColonDelimited( const QString &txt )
   // 64321c05b0ebab8e2b67ec0d7d9e2b6d4bc3c303
   //   -> 64:32:1c:05:b0:eb:ab:8e:2b:67:ec:0d:7d:9e:2b:6d:4b:c3:c3:03
   QStringList sl;
+  sl.reserve( txt.size() );
   for ( int i = 0; i < txt.size(); i += 2 )
   {
     sl << txt.mid( i, ( i + 2 > txt.size() ) ? -1 : 2 );
@@ -593,7 +594,7 @@ QList<QgsAuthCertUtils::CertUsageType> QgsAuthCertUtils::certificateUsageTypes(
   }
 
   QList<QCA::ConstraintType> certconsts = qcacert.constraints();
-  Q_FOREACH ( QCA::ConstraintType certconst, certconsts )
+  Q_FOREACH ( const QCA::ConstraintType& certconst, certconsts )
   {
     if ( certconst.known() == QCA::KeyCertificateSign )
     {
diff --git a/src/core/auth/qgsauthconfig.cpp b/src/core/auth/qgsauthconfig.cpp
index ed38aaf22ed..8c2b7c115a1 100644
--- a/src/core/auth/qgsauthconfig.cpp
+++ b/src/core/auth/qgsauthconfig.cpp
@@ -285,7 +285,7 @@ const QgsPkiBundle QgsPkiBundle::fromPkcs12Paths( const QString &bundlepath,
       if ( cert_chain.size() > 1 )
       {
         QList<QSslCertificate> ca_chain;
-        Q_FOREACH ( QCA::Certificate ca_cert, cert_chain )
+        Q_FOREACH ( const QCA::Certificate& ca_cert, cert_chain )
         {
           if ( ca_cert != cert_chain.primary() )
           {
diff --git a/src/core/auth/qgsauthmanager.cpp b/src/core/auth/qgsauthmanager.cpp
index 68a603c975d..c907dccba02 100644
--- a/src/core/auth/qgsauthmanager.cpp
+++ b/src/core/auth/qgsauthmanager.cpp
@@ -2328,7 +2328,7 @@ const QList<QSslCertificate> QgsAuthManager::getExtraFileCAs()
     filecerts = QgsAuthCertUtils::certsFromFile( cafile );
   }
   // only CAs or certs capable of signing other certs are allowed
-  Q_FOREACH ( QSslCertificate cert, filecerts )
+  Q_FOREACH ( const QSslCertificate& cert, filecerts )
   {
     if ( !allowinvalid.toBool() && !cert.isValid() )
     {
diff --git a/src/core/composer/qgscomposerlegend.cpp b/src/core/composer/qgscomposerlegend.cpp
index e0f2f888dc9..85a4943f72f 100644
--- a/src/core/composer/qgscomposerlegend.cpp
+++ b/src/core/composer/qgscomposerlegend.cpp
@@ -235,10 +235,10 @@ QString QgsComposerLegend::wrapChar() const {return mSettings.wrapChar(); }
 int QgsComposerLegend::columnCount() const { return mSettings.columnCount(); }
 void QgsComposerLegend::setColumnCount( int c ) { mSettings.setColumnCount( c ); }
 
-int QgsComposerLegend::splitLayer() const { return mSettings.splitLayer(); }
+bool QgsComposerLegend::splitLayer() const { return mSettings.splitLayer(); }
 void QgsComposerLegend::setSplitLayer( bool s ) { mSettings.setSplitLayer( s ); }
 
-int QgsComposerLegend::equalColumnWidth() const { return mSettings.equalColumnWidth(); }
+bool QgsComposerLegend::equalColumnWidth() const { return mSettings.equalColumnWidth(); }
 void QgsComposerLegend::setEqualColumnWidth( bool s ) { mSettings.setEqualColumnWidth( s ); }
 
 
diff --git a/src/core/composer/qgscomposerlegend.h b/src/core/composer/qgscomposerlegend.h
index 649f4d4d944..bc5d9fc471e 100644
--- a/src/core/composer/qgscomposerlegend.h
+++ b/src/core/composer/qgscomposerlegend.h
@@ -150,10 +150,10 @@ class CORE_EXPORT QgsComposerLegend : public QgsComposerItem
     int columnCount() const;
     void setColumnCount( int c );
 
-    int splitLayer() const;
+    bool splitLayer() const;
     void setSplitLayer( bool s );
 
-    int equalColumnWidth() const;
+    bool equalColumnWidth() const;
     void setEqualColumnWidth( bool s );
 
     void setComposerMap( const QgsComposerMap* map );
diff --git a/src/core/composer/qgscomposermap.cpp b/src/core/composer/qgscomposermap.cpp
index 5acd9c6a100..32bab16e90e 100644
--- a/src/core/composer/qgscomposermap.cpp
+++ b/src/core/composer/qgscomposermap.cpp
@@ -1425,6 +1425,7 @@ bool QgsComposerMap::readXML( const QDomElement& itemElem, const QDomDocument& d
   {
     QDomElement layerSetElem = layerSetNodeList.at( 0 ).toElement();
     QDomNodeList layerIdNodeList = layerSetElem.elementsByTagName( "Layer" );
+    layerSet.reserve( layerIdNodeList.size() );
     for ( int i = 0; i < layerIdNodeList.size(); ++i )
     {
       const QDomElement& layerIdElement = layerIdNodeList.at( i ).toElement();
diff --git a/src/core/dxf/qgsdxfexport.cpp b/src/core/dxf/qgsdxfexport.cpp
index bdc9d54191c..75b8971f6f7 100644
--- a/src/core/dxf/qgsdxfexport.cpp
+++ b/src/core/dxf/qgsdxfexport.cpp
@@ -4127,7 +4127,7 @@ QString QgsDxfExport::layerName( const QString &id, const QgsFeature &f ) const
 
 QString QgsDxfExport::dxfEncoding( const QString &name )
 {
-  Q_FOREACH ( QByteArray codec, QTextCodec::availableCodecs() )
+  Q_FOREACH ( const QByteArray& codec, QTextCodec::availableCodecs() )
   {
     if ( name != codec )
       continue;
diff --git a/src/core/geometry/qgscurvepolygonv2.cpp b/src/core/geometry/qgscurvepolygonv2.cpp
index e5039dd339d..9b523cc9678 100644
--- a/src/core/geometry/qgscurvepolygonv2.cpp
+++ b/src/core/geometry/qgscurvepolygonv2.cpp
@@ -358,7 +358,9 @@ QgsPolygonV2* QgsCurvePolygonV2::surfaceToPolygon() const
   QgsPolygonV2* polygon = new QgsPolygonV2();
   polygon->setExteriorRing( exteriorRing()->curveToLine() );
   QList<QgsCurveV2*> interiors;
-  for ( int i = 0, n = numInteriorRings(); i < n; ++i )
+  int n = numInteriorRings();
+  interiors.reserve( n );
+  for ( int i = 0; i < n; ++i )
   {
     interiors.append( interiorRing( i )->curveToLine() );
   }
@@ -681,6 +683,7 @@ double QgsCurvePolygonV2::vertexAngle( const QgsVertexId& vertex ) const
 {
   if ( !mExteriorRing || vertex.ring < 0 || vertex.ring >= 1 + mInteriorRings.size() )
   {
+    //makes no sense - conversion of false to double!
     return false;
   }
 
diff --git a/src/core/geometry/qgscurvepolygonv2.h b/src/core/geometry/qgscurvepolygonv2.h
index 5c94780701d..68471baf90c 100644
--- a/src/core/geometry/qgscurvepolygonv2.h
+++ b/src/core/geometry/qgscurvepolygonv2.h
@@ -100,7 +100,7 @@ class CORE_EXPORT QgsCurvePolygonV2: public QgsSurfaceV2
 
     virtual int vertexCount( int /*part*/ = 0, int ring = 0 ) const override;
     virtual int ringCount( int /*part*/ = 0 ) const override { return ( mExteriorRing != 0 ) + mInteriorRings.size(); }
-    virtual int partCount() const override { return ringCount() > 0; }
+    virtual int partCount() const override { return ringCount() > 0 ? 1 : 0; }
     virtual QgsPointV2 vertexAt( const QgsVertexId& id ) const override;
 
   protected:
diff --git a/src/core/geometry/qgscurvev2.h b/src/core/geometry/qgscurvev2.h
index e7fd9ce3aad..c6c15d2ba8c 100644
--- a/src/core/geometry/qgscurvev2.h
+++ b/src/core/geometry/qgscurvev2.h
@@ -92,8 +92,8 @@ class CORE_EXPORT QgsCurveV2: public QgsAbstractGeometryV2
     QgsAbstractGeometryV2* segmentize() const override;
 
     virtual int vertexCount( int /*part*/ = 0, int /*ring*/ = 0 ) const override { return numPoints(); }
-    virtual int ringCount( int /*part*/ = 0 ) const override { return numPoints() > 0; }
-    virtual int partCount() const override { return numPoints() > 0; }
+    virtual int ringCount( int /*part*/ = 0 ) const override { return numPoints() > 0 ? 1 : 0; }
+    virtual int partCount() const override { return numPoints() > 0 ? 1 : 0; }
     virtual QgsPointV2 vertexAt( const QgsVertexId& id ) const override;
 };
 
diff --git a/src/core/geometry/qgsgeometry.cpp b/src/core/geometry/qgsgeometry.cpp
index 77018b0750c..6331ceffed0 100644
--- a/src/core/geometry/qgsgeometry.cpp
+++ b/src/core/geometry/qgsgeometry.cpp
@@ -1415,6 +1415,7 @@ QList<QgsGeometry*> QgsGeometry::asGeometryCollection() const
   if ( gc )
   {
     int numGeom = gc->numGeometries();
+    geometryList.reserve( numGeom );
     for ( int i = 0; i < numGeom; ++i )
     {
       geometryList.append( new QgsGeometry( gc->geometryN( i )->clone() ) );
@@ -1683,7 +1684,7 @@ int QgsGeometry::vertexNrFromVertexId( const QgsVertexId& id ) const
 {
   if ( !d || !d->geometry )
   {
-    return false;
+    return -1;
   }
 
   QList< QList< QList< QgsPointV2 > > > coords;
@@ -1911,6 +1912,7 @@ QgsPolyline QgsGeometry::smoothLine( const QgsPolyline& polyline, const unsigned
   for ( unsigned int iteration = 0; iteration < iterations; ++iteration )
   {
     QgsPolyline outputLine = QgsPolyline();
+    outputLine.reserve( 2 * ( result.count() - 1 ) );
     for ( int i = 0; i < result.count() - 1; i++ )
     {
       const QgsPoint& p1 = result.at( i );
@@ -1933,6 +1935,7 @@ QgsPolygon QgsGeometry::smoothPolygon( const QgsPolygon& polygon, const unsigned
     for ( unsigned int iteration = 0; iteration < iterations; ++iteration )
     {
       QgsPolyline outputRing = QgsPolyline();
+      outputRing.reserve( 2 * ( resultRing.count() - 1 ) + 1 );
       for ( int i = 0; i < resultRing.count() - 1; ++i )
       {
         const QgsPoint& p1 = resultRing.at( i );
diff --git a/src/core/geometry/qgsgeometry.h b/src/core/geometry/qgsgeometry.h
index 996493e3930..9c03f495b95 100644
--- a/src/core/geometry/qgsgeometry.h
+++ b/src/core/geometry/qgsgeometry.h
@@ -575,7 +575,7 @@ class CORE_EXPORT QgsGeometry
       public:
         Error() : message( "none" ), hasLocation( false ) {}
         explicit Error( QString m ) : message( m ), hasLocation( false ) {}
-        Error( QString m, QgsPoint p ) : message( m ), location( p ), hasLocation( true ) {}
+        Error( QString m, const QgsPoint& p ) : message( m ), location( p ), hasLocation( true ) {}
 
         QString what() { return message; }
         QgsPoint where() { return location; }
diff --git a/src/core/geometry/qgsgeometryeditutils.cpp b/src/core/geometry/qgsgeometryeditutils.cpp
index 4aa9967d3e2..6ee1961427a 100644
--- a/src/core/geometry/qgsgeometryeditutils.cpp
+++ b/src/core/geometry/qgsgeometryeditutils.cpp
@@ -42,6 +42,7 @@ int QgsGeometryEditUtils::addRing( QgsAbstractGeometryV2* geom, QgsCurveV2* ring
   }
   else if ( multiGeom )
   {
+    polygonList.reserve( multiGeom->numGeometries() );
     for ( int i = 0; i < multiGeom->numGeometries(); ++i )
     {
       polygonList.append( dynamic_cast< QgsCurvePolygonV2* >( multiGeom->geometryN( i ) ) );
diff --git a/src/core/geometry/qgsgeos.cpp b/src/core/geometry/qgsgeos.cpp
index 74977c07c70..ddb7c3fe57c 100644
--- a/src/core/geometry/qgsgeos.cpp
+++ b/src/core/geometry/qgsgeos.cpp
@@ -561,6 +561,7 @@ int QgsGeos::splitLinearGeometry( GEOSGeometry* splitLine, QList<QgsAbstractGeom
   if ( splitType == GEOS_MULTILINESTRING )
   {
     int nGeoms = GEOSGetNumGeometries_r( geosinit.ctxt, splitGeom );
+    lineGeoms.reserve( nGeoms );
     for ( int i = 0; i < nGeoms; ++i )
       lineGeoms << GEOSGeom_clone_r( geosinit.ctxt, GEOSGetGeometryN_r( geosinit.ctxt, splitGeom, i ) );
 
@@ -930,6 +931,7 @@ QgsLineStringV2* QgsGeos::sequenceToLinestring( const GEOSGeometry* geos, bool h
   const GEOSCoordSequence* cs = GEOSGeom_getCoordSeq_r( geosinit.ctxt, geos );
   unsigned int nPoints;
   GEOSCoordSeq_getSize_r( geosinit.ctxt, cs, &nPoints );
+  pts.reserve( nPoints );
   for ( unsigned int i = 0; i < nPoints; ++i )
   {
     pts.push_back( coordSeqPoint( cs, i, hasZ, hasM ) );
diff --git a/src/core/geometry/qgspolygonv2.cpp b/src/core/geometry/qgspolygonv2.cpp
index 23f7431de80..163566c796b 100644
--- a/src/core/geometry/qgspolygonv2.cpp
+++ b/src/core/geometry/qgspolygonv2.cpp
@@ -107,5 +107,5 @@ unsigned char* QgsPolygonV2::asWkb( int& binarySize ) const
 
 QgsPolygonV2* QgsPolygonV2::surfaceToPolygon() const
 {
-  return dynamic_cast<QgsPolygonV2*>( clone() );
+  return clone();
 }
diff --git a/src/core/pal/rtree.hpp b/src/core/pal/rtree.hpp
index d12fad62065..b597f903ddd 100644
--- a/src/core/pal/rtree.hpp
+++ b/src/core/pal/rtree.hpp
@@ -970,7 +970,7 @@ namespace pal
   {
     ASSERT( a_node );
 
-    int firstTime = true;
+    bool firstTime = true;
     Rect rect;
     InitRect( &rect );
 
diff --git a/src/core/qgsconditionalstyle.cpp b/src/core/qgsconditionalstyle.cpp
index 9baa6b09a0d..54f0fd355eb 100644
--- a/src/core/qgsconditionalstyle.cpp
+++ b/src/core/qgsconditionalstyle.cpp
@@ -88,6 +88,7 @@ bool QgsConditionalLayerStyles::readXml( const QDomNode &node )
     QDomElement fieldel = nodelist.at( i ).toElement();
     QString fieldName = fieldel.attribute( "fieldname" );
     QDomNodeList stylenodelist = fieldel.toElement().elementsByTagName( "style" );
+    styles.reserve( stylenodelist.count() );
     for ( int i = 0;i < stylenodelist.count(); i++ )
     {
       QDomElement styleElm = stylenodelist.at( i ).toElement();
diff --git a/src/core/qgsdiagramrendererv2.cpp b/src/core/qgsdiagramrendererv2.cpp
index 8c5071d2b1c..5af2ce23d4a 100644
--- a/src/core/qgsdiagramrendererv2.cpp
+++ b/src/core/qgsdiagramrendererv2.cpp
@@ -548,6 +548,7 @@ void QgsLinearlyInterpolatedDiagramRenderer::writeXML( QDomElement& layerElem, Q
 QList< QgsLayerTreeModelLegendNode* > QgsDiagramSettings::legendItems( QgsLayerTreeLayer* nodeLayer ) const
 {
   QList< QgsLayerTreeModelLegendNode * > list;
+  list.reserve( categoryLabels.size() );
   for ( int i = 0 ; i < categoryLabels.size(); ++i )
   {
     QPixmap pix( 16, 16 );
diff --git a/src/core/qgsdistancearea.cpp b/src/core/qgsdistancearea.cpp
index de0d6307696..970a3194922 100644
--- a/src/core/qgsdistancearea.cpp
+++ b/src/core/qgsdistancearea.cpp
@@ -369,6 +369,7 @@ double QgsDistanceArea::measurePerimeter( const QgsGeometry* geometry ) const
   const QgsMultiSurfaceV2* multiSurf = dynamic_cast<const QgsMultiSurfaceV2*>( geomV2 );
   if ( multiSurf )
   {
+    surfaces.reserve(( surf ? 1 : 0 ) + multiSurf->numGeometries() );
     for ( int i = 0; i  < multiSurf->numGeometries(); ++i )
     {
       surfaces.append( static_cast<const QgsSurfaceV2*>( multiSurf->geometryN( i ) ) );
@@ -376,7 +377,6 @@ double QgsDistanceArea::measurePerimeter( const QgsGeometry* geometry ) const
   }
 
   double length = 0;
-  QList<QgsPointV2> pointList;
   QList<const QgsSurfaceV2*>::const_iterator surfaceIt = surfaces.constBegin();
   for ( ; surfaceIt != surfaces.constEnd(); ++surfaceIt )
   {
diff --git a/src/core/qgshistogram.cpp b/src/core/qgshistogram.cpp
index 250a148fa96..0bee53c301f 100644
--- a/src/core/qgshistogram.cpp
+++ b/src/core/qgshistogram.cpp
@@ -83,6 +83,7 @@ QList<double> QgsHistogram::binEdges( int bins ) const
   double binWidth = ( mMax - mMin ) / bins;
 
   QList<double> edges;
+  edges.reserve( bins + 1 );
   edges << mMin;
   double current = mMin;
   for ( int i = 0; i < bins; ++i )
diff --git a/src/core/qgslabelsearchtree.cpp b/src/core/qgslabelsearchtree.cpp
index 3dce5bd385f..ecb73e87a9f 100644
--- a/src/core/qgslabelsearchtree.cpp
+++ b/src/core/qgslabelsearchtree.cpp
@@ -79,6 +79,7 @@ bool QgsLabelSearchTree::insertLabel( LabelPosition* labelPos, int featureId, co
   labelPos->getBoundingBox( c_min, c_max );
 
   QVector<QgsPoint> cornerPoints;
+  cornerPoints.reserve( 4 );
   for ( int i = 0; i < 4; ++i )
   {
     cornerPoints.push_back( QgsPoint( labelPos->getX( i ), labelPos->getY( i ) ) );
diff --git a/src/core/qgslegendsettings.h b/src/core/qgslegendsettings.h
index 9b2d11bc029..675f68e3a41 100644
--- a/src/core/qgslegendsettings.h
+++ b/src/core/qgslegendsettings.h
@@ -70,10 +70,10 @@ class CORE_EXPORT QgsLegendSettings
     int columnCount() const { return mColumnCount; }
     void setColumnCount( int c ) { mColumnCount = c;}
 
-    int splitLayer() const { return mSplitLayer; }
+    bool splitLayer() const { return mSplitLayer; }
     void setSplitLayer( bool s ) { mSplitLayer = s;}
 
-    int equalColumnWidth() const { return mEqualColumnWidth; }
+    bool equalColumnWidth() const { return mEqualColumnWidth; }
     void setEqualColumnWidth( bool s ) { mEqualColumnWidth = s;}
 
     QColor fontColor() const {return mFontColor;}
diff --git a/src/core/qgsmaplayerlegend.cpp b/src/core/qgsmaplayerlegend.cpp
index b4b131a552d..ecf76231a78 100644
--- a/src/core/qgsmaplayerlegend.cpp
+++ b/src/core/qgsmaplayerlegend.cpp
@@ -79,6 +79,7 @@ static QList<int> _makeNodeOrder( QgsLayerTreeLayer* nodeLayer )
   int numNodes = _originalLegendNodeCount( nodeLayer );
 
   QList<int> order;
+  order.reserve( numNodes );
   for ( int i = 0; i < numNodes; ++i )
     order << i;
   return order;
@@ -287,7 +288,7 @@ QList<QgsLayerTreeModelLegendNode*> QgsDefaultPluginLayerLegend::createLayerTree
     return nodes;
 
   typedef QPair<QString, QPixmap> XY;
-  Q_FOREACH ( XY item, symbologyList )
+  Q_FOREACH ( const XY& item, symbologyList )
   {
     nodes << new QgsSimpleLegendNode( nodeLayer, item.first, QIcon( item.second ) );
   }
diff --git a/src/core/qgspoint.h b/src/core/qgspoint.h
index 38dfe5f9ade..7c1401a44ec 100644
--- a/src/core/qgspoint.h
+++ b/src/core/qgspoint.h
@@ -215,7 +215,7 @@ class CORE_EXPORT QgsPoint
     //! Assignment
     QgsPoint & operator=( const QgsPoint &other );
 
-    QgsVector operator-( QgsPoint p ) const { return QgsVector( m_x - p.m_x, m_y - p.m_y ); }
+    QgsVector operator-( const QgsPoint& p ) const { return QgsVector( m_x - p.m_x, m_y - p.m_y ); }
     QgsPoint &operator+=( const QgsVector &v ) { *this = *this + v; return *this; }
     QgsPoint &operator-=( const QgsVector &v ) { *this = *this - v; return *this; }
     QgsPoint operator+( const QgsVector &v ) const { return QgsPoint( m_x + v.x(), m_y + v.y() ); }
diff --git a/src/core/qgsvectorlayer.h b/src/core/qgsvectorlayer.h
index f0ff8281c95..f72947c21f4 100644
--- a/src/core/qgsvectorlayer.h
+++ b/src/core/qgsvectorlayer.h
@@ -678,7 +678,7 @@ class CORE_EXPORT QgsVectorLayer : public QgsMapLayer
     struct RangeData
     {
       RangeData() { mMin = QVariant( 0 ); mMax = QVariant( 5 ); mStep = QVariant( 1 );}
-      RangeData( QVariant theMin, QVariant theMax, QVariant theStep )
+      RangeData( const QVariant& theMin, const QVariant& theMax, const QVariant& theStep )
           : mMin( theMin ), mMax( theMax ), mStep( theStep ) {}
 
       QVariant mMin;
diff --git a/src/core/qgsvectorlayerimport.cpp b/src/core/qgsvectorlayerimport.cpp
index 882211ae2f9..36e1b3712f7 100644
--- a/src/core/qgsvectorlayerimport.cpp
+++ b/src/core/qgsvectorlayerimport.cpp
@@ -215,7 +215,7 @@ QgsVectorLayerImport::importLayer( QgsVectorLayer* layer,
 {
   const QgsCoordinateReferenceSystem* outputCRS;
   QgsCoordinateTransform* ct = 0;
-  int shallTransform = false;
+  bool shallTransform = false;
 
   if ( layer == NULL )
   {
diff --git a/src/core/raster/qgsrasterfilewriter.cpp b/src/core/raster/qgsrasterfilewriter.cpp
index 03b0e7e5f1b..14c4ac58651 100644
--- a/src/core/raster/qgsrasterfilewriter.cpp
+++ b/src/core/raster/qgsrasterfilewriter.cpp
@@ -335,6 +335,7 @@ QgsRasterFileWriter::WriterError QgsRasterFileWriter::writeDataRaster(
   int iterRows = 0;
 
   QList<QgsRasterBlock*> blockList;
+  blockList.reserve( nBands );
   for ( int i = 1; i <= nBands; ++i )
   {
     iter->startRasterRead( i, nCols, nRows, outputExtent );
diff --git a/src/core/raster/qgsrasterlayer.cpp b/src/core/raster/qgsrasterlayer.cpp
index c95b42faf16..c0c4a1670c8 100644
--- a/src/core/raster/qgsrasterlayer.cpp
+++ b/src/core/raster/qgsrasterlayer.cpp
@@ -1438,6 +1438,7 @@ bool QgsRasterLayer::readXml( const QDomNode& layer_node )
 
       QDomNodeList rangeList = bandElement.elementsByTagName( "noDataRange" );
 
+      myNoDataRangeList.reserve( rangeList.size() );
       for ( int j = 0; j < rangeList.size(); ++j )
       {
         QDomElement rangeElement = rangeList.at( j ).toElement();
diff --git a/src/core/raster/qgsrasterprojector.cpp b/src/core/raster/qgsrasterprojector.cpp
index cc0e23daf10..3d042db8924 100644
--- a/src/core/raster/qgsrasterprojector.cpp
+++ b/src/core/raster/qgsrasterprojector.cpp
@@ -692,7 +692,9 @@ void QgsRasterProjector::insertRows( const QgsCoordinateTransform* ct )
   {
     QList<QgsPoint> myRow;
     QList<bool> myLegalRow;
-    for ( int c = 0; c < mCPCols; c++ )
+    myRow.reserve( mCPCols );
+    myLegalRow.reserve( mCPCols );
+    for ( int c = 0; c < mCPCols; ++c )
     {
       myRow.append( QgsPoint() );
       myLegalRow.append( false );
diff --git a/src/core/raster/qgsrastershader.cpp b/src/core/raster/qgsrastershader.cpp
index f12f05f0832..cb708120104 100644
--- a/src/core/raster/qgsrastershader.cpp
+++ b/src/core/raster/qgsrastershader.cpp
@@ -178,6 +178,7 @@ void QgsRasterShader::readXML( const QDomElement& elem )
     QColor itemColor;
 
     QDomNodeList itemNodeList = colorRampShaderElem.elementsByTagName( "item" );
+    itemList.reserve( itemNodeList.size() );
     for ( int i = 0; i < itemNodeList.size(); ++i )
     {
       itemElem = itemNodeList.at( i ).toElement();
diff --git a/src/core/symbology-ng/qgscategorizedsymbolrendererv2.cpp b/src/core/symbology-ng/qgscategorizedsymbolrendererv2.cpp
index fa14e37ad61..ad218f8c297 100644
--- a/src/core/symbology-ng/qgscategorizedsymbolrendererv2.cpp
+++ b/src/core/symbology-ng/qgscategorizedsymbolrendererv2.cpp
@@ -522,6 +522,7 @@ QgsSymbolV2List QgsCategorizedSymbolRendererV2::symbols( QgsRenderContext &conte
 {
   Q_UNUSED( context );
   QgsSymbolV2List lst;
+  lst.reserve( mCategories.count() );
   for ( int i = 0; i < mCategories.count(); i++ )
     lst.append( mCategories[i].symbol() );
   return lst;
@@ -697,6 +698,7 @@ QgsLegendSymbologyList QgsCategorizedSymbolRendererV2::legendSymbologyItems( QSi
 {
   QgsLegendSymbologyList lst;
   int count = categories().count();
+  lst.reserve( count );
   for ( int i = 0; i < count; i++ )
   {
     const QgsRendererCategoryV2& cat = categories()[i];
diff --git a/src/core/symbology-ng/qgsellipsesymbollayerv2.cpp b/src/core/symbology-ng/qgsellipsesymbollayerv2.cpp
index f5485c69cc5..382f0e47528 100644
--- a/src/core/symbology-ng/qgsellipsesymbollayerv2.cpp
+++ b/src/core/symbology-ng/qgsellipsesymbollayerv2.cpp
@@ -683,6 +683,7 @@ bool QgsEllipseSymbolLayerV2::writeDxf( QgsDxfExport& e, double mmMapUnitScaleFa
     else
     {
       QgsPolyline line;
+      line.reserve( 40 );
       double stepsize = 2 * M_PI / 40;
       for ( int i = 0; i < 39; ++i )
       {
diff --git a/src/core/symbology-ng/qgsgraduatedsymbolrendererv2.cpp b/src/core/symbology-ng/qgsgraduatedsymbolrendererv2.cpp
index 35a2c39bdd2..af306d4b63a 100644
--- a/src/core/symbology-ng/qgsgraduatedsymbolrendererv2.cpp
+++ b/src/core/symbology-ng/qgsgraduatedsymbolrendererv2.cpp
@@ -549,6 +549,7 @@ QgsSymbolV2List QgsGraduatedSymbolRendererV2::symbols( QgsRenderContext &context
 {
   Q_UNUSED( context );
   QgsSymbolV2List lst;
+  lst.reserve( mRanges.count() );
   for ( int i = 0; i < mRanges.count(); i++ )
     lst.append( mRanges[i].symbol() );
   return lst;
@@ -566,6 +567,7 @@ static QList<double> _calcEqualIntervalBreaks( double minimum, double maximum, i
 
   QList<double> breaks;
   double value = minimum;
+  breaks.reserve( classes );
   for ( int i = 0; i < classes; i++ )
   {
     value += step;
@@ -601,6 +603,7 @@ static QList<double> _calcQuantileBreaks( QList<double> values, int classes )
   int n = values.count();
   double Xq = n > 0 ? values[0] : 0.0;
 
+  breaks.reserve( classes );
   for ( int i = 1; i < classes; i++ )
   {
     if ( n > 1 )
@@ -1167,6 +1170,7 @@ QgsLegendSymbologyList QgsGraduatedSymbolRendererV2::legendSymbologyItems( QSize
 {
   QgsLegendSymbologyList lst;
   int count = ranges().count();
+  lst.reserve( count );
   for ( int i = 0; i < count; i++ )
   {
     const QgsRendererRangeV2& range = ranges()[i];
diff --git a/src/core/symbology-ng/qgsheatmaprenderer.h b/src/core/symbology-ng/qgsheatmaprenderer.h
index 18799beaa1c..a2fab324a1d 100644
--- a/src/core/symbology-ng/qgsheatmaprenderer.h
+++ b/src/core/symbology-ng/qgsheatmaprenderer.h
@@ -72,7 +72,8 @@ class CORE_EXPORT QgsHeatmapRenderer : public QgsFeatureRendererV2
      * @see setInvertRamp
      * @see colorRamp
     */
-    double invertRamp() const { return mInvertRamp; }
+    bool invertRamp() const { return mInvertRamp; }
+
     /** Sets whether the ramp is inverted
      * @param invert set to true to invert color ramp
      * @see invertRamp
diff --git a/src/core/symbology-ng/qgsrendererv2.cpp b/src/core/symbology-ng/qgsrendererv2.cpp
index 82380896024..3bdf54b7d2b 100644
--- a/src/core/symbology-ng/qgsrendererv2.cpp
+++ b/src/core/symbology-ng/qgsrendererv2.cpp
@@ -699,7 +699,7 @@ bool QgsFeatureRendererV2::willRenderFeature( QgsFeature &feat, QgsRenderContext
   return symbolForFeature( feat, context ) != NULL;
 }
 
-void QgsFeatureRendererV2::renderVertexMarker( QPointF& pt, QgsRenderContext& context )
+void QgsFeatureRendererV2::renderVertexMarker( const QPointF &pt, QgsRenderContext& context )
 {
   QgsVectorLayer::drawVertexMarker( pt.x(), pt.y(), *context.painter(),
                                     ( QgsVectorLayer::VertexMarkerType ) mCurrentVertexMarkerType,
@@ -708,20 +708,20 @@ void QgsFeatureRendererV2::renderVertexMarker( QPointF& pt, QgsRenderContext& co
 
 void QgsFeatureRendererV2::renderVertexMarkerPolyline( QPolygonF& pts, QgsRenderContext& context )
 {
-  Q_FOREACH ( QPointF pt, pts )
+  Q_FOREACH ( const QPointF& pt, pts )
     renderVertexMarker( pt, context );
 }
 
 void QgsFeatureRendererV2::renderVertexMarkerPolygon( QPolygonF& pts, QList<QPolygonF>* rings, QgsRenderContext& context )
 {
-  Q_FOREACH ( QPointF pt, pts )
+  Q_FOREACH ( const QPointF& pt, pts )
     renderVertexMarker( pt, context );
 
   if ( rings )
   {
-    Q_FOREACH ( QPolygonF ring, *rings )
+    Q_FOREACH ( const QPolygonF& ring, *rings )
     {
-      Q_FOREACH ( QPointF pt, ring )
+      Q_FOREACH ( const QPointF& pt, ring )
         renderVertexMarker( pt, context );
     }
   }
diff --git a/src/core/symbology-ng/qgsrendererv2.h b/src/core/symbology-ng/qgsrendererv2.h
index bac4ff39ab1..abd60b6aa35 100644
--- a/src/core/symbology-ng/qgsrendererv2.h
+++ b/src/core/symbology-ng/qgsrendererv2.h
@@ -322,7 +322,7 @@ class CORE_EXPORT QgsFeatureRendererV2
                                   bool drawVertexMarker );
 
     //! render editing vertex marker at specified point
-    void renderVertexMarker( QPointF& pt, QgsRenderContext& context );
+    void renderVertexMarker( const QPointF& pt, QgsRenderContext& context );
     //! render editing vertex marker for a polyline
     void renderVertexMarkerPolyline( QPolygonF& pts, QgsRenderContext& context );
     //! render editing vertex marker for a polygon
diff --git a/src/core/symbology-ng/qgssymbollayerv2utils.cpp b/src/core/symbology-ng/qgssymbollayerv2utils.cpp
index 6b24e3b8bfe..3070f79da36 100644
--- a/src/core/symbology-ng/qgssymbollayerv2utils.cpp
+++ b/src/core/symbology-ng/qgssymbollayerv2utils.cpp
@@ -733,6 +733,7 @@ static QPolygonF makeOffsetGeometry( const QgsPolyline& polyline )
 static QList<QPolygonF> makeOffsetGeometry( const QgsPolygon& polygon )
 {
   QList<QPolygonF> resultGeom;
+  resultGeom.reserve( polygon.size() );
   for ( int ring = 0; ring < polygon.size(); ++ring )
     resultGeom.append( makeOffsetGeometry( polygon[ ring ] ) );
   return resultGeom;
@@ -793,7 +794,7 @@ QList<QPolygonF> offsetLine( QPolygonF polyline, double dist, QGis::GeometryType
       else if ( QGis::flatType( tempGeometry->wkbType() ) == QGis::WKBMultiLineString )
       {
         QgsMultiPolyline tempMPolyline = tempGeometry->asMultiPolyline();
-
+        resultLine.reserve( tempMPolyline.count() );
         for ( int part = 0; part < tempMPolyline.count(); ++part )
         {
           resultLine.append( makeOffsetGeometry( tempMPolyline[ part ] ) );
@@ -804,7 +805,7 @@ QList<QPolygonF> offsetLine( QPolygonF polyline, double dist, QGis::GeometryType
       else if ( QGis::flatType( tempGeometry->wkbType() ) == QGis::WKBMultiPolygon )
       {
         QgsMultiPolygon tempMPolygon = tempGeometry->asMultiPolygon();
-
+        resultLine.reserve( tempMPolygon.count() );
         for ( int part = 0; part < tempMPolygon.count(); ++part )
         {
           resultLine.append( makeOffsetGeometry( tempMPolygon[ part ] ) );
@@ -2316,7 +2317,7 @@ bool QgsSymbolLayerV2Utils::displacementFromSldElement( QDomElement &element, QP
 }
 
 void QgsSymbolLayerV2Utils::labelTextToSld( QDomDocument &doc, QDomElement &element,
-    QString label, QFont font,
+    QString label, const QFont& font,
     QColor color, double size )
 {
   QDomElement labelElem = doc.createElement( "se:Label" );
@@ -3967,6 +3968,7 @@ QList<double> QgsSymbolLayerV2Utils::prettyBreaks( double minimum, double maximu
   //double maximumBreak = end * unit;
   int count = end - start;
 
+  breaks.reserve( count );
   for ( int i = 1; i < count + 1; i++ )
   {
     breaks.append( minimumBreak + i * unit );
diff --git a/src/core/symbology-ng/qgssymbollayerv2utils.h b/src/core/symbology-ng/qgssymbollayerv2utils.h
index 639264e90fc..5795493b7ff 100644
--- a/src/core/symbology-ng/qgssymbollayerv2utils.h
+++ b/src/core/symbology-ng/qgssymbollayerv2utils.h
@@ -221,7 +221,7 @@ class CORE_EXPORT QgsSymbolLayerV2Utils
 
 
     static void labelTextToSld( QDomDocument &doc, QDomElement &element, QString label,
-                                QFont font, QColor color = QColor(), double size = -1 );
+                                const QFont &font, QColor color = QColor(), double size = -1 );
 
     /** Create ogr feature style string for pen */
     static QString ogrFeatureStylePen( double width, double mmScaleFactor, double mapUnitsScaleFactor, const QColor& c,
diff --git a/src/core/symbology-ng/qgssymbolv2.h b/src/core/symbology-ng/qgssymbolv2.h
index 5aee181755b..c8732062568 100644
--- a/src/core/symbology-ng/qgssymbolv2.h
+++ b/src/core/symbology-ng/qgssymbolv2.h
@@ -213,7 +213,7 @@ class CORE_EXPORT QgsSymbolV2
      * @note added in QGIS 2.9
      * @see setClipFeaturesToExtent
      */
-    double clipFeaturesToExtent() const { return mClipFeaturesToExtent; }
+    bool clipFeaturesToExtent() const { return mClipFeaturesToExtent; }
 
     QSet<QString> usedAttributes() const;
 
diff --git a/src/core/symbology-ng/qgsvectorcolorrampv2.cpp b/src/core/symbology-ng/qgsvectorcolorrampv2.cpp
index 3fce378f167..615e32694e0 100644
--- a/src/core/symbology-ng/qgsvectorcolorrampv2.cpp
+++ b/src/core/symbology-ng/qgsvectorcolorrampv2.cpp
@@ -340,7 +340,8 @@ QList<QColor> QgsVectorRandomColorRampV2::randomColors( int count,
   //start hue at random angle
   double currentHueAngle = 360.0 * ( double )qrand() / RAND_MAX;
 
-  for ( int i = 0; i < count; i++ )
+  colors.reserve( count );
+  for ( int i = 0; i < count; ++i )
   {
     //increment hue by golden ratio (approx 137.507 degrees)
     //as this minimises hue nearness as count increases
diff --git a/src/gui/attributetable/qgsattributetablemodel.cpp b/src/gui/attributetable/qgsattributetablemodel.cpp
index 6f517615cf8..57969b5afb3 100644
--- a/src/gui/attributetable/qgsattributetablemodel.cpp
+++ b/src/gui/attributetable/qgsattributetablemodel.cpp
@@ -450,7 +450,9 @@ QModelIndexList QgsAttributeTableModel::idToIndexList( QgsFeatureId id ) const
   QModelIndexList indexes;
 
   int row = idToRow( id );
-  for ( int column = 0; column < columnCount(); ++column )
+  int columns = columnCount();
+  indexes.reserve( columns );
+  for ( int column = 0; column < columns; ++column )
   {
     indexes.append( index( row, column ) );
   }
diff --git a/src/gui/attributetable/qgsfeatureselectionmodel.cpp b/src/gui/attributetable/qgsfeatureselectionmodel.cpp
index 27029aa95bb..af9e7cfb4b8 100644
--- a/src/gui/attributetable/qgsfeatureselectionmodel.cpp
+++ b/src/gui/attributetable/qgsfeatureselectionmodel.cpp
@@ -171,7 +171,9 @@ QModelIndexList QgsFeatureSelectionModel::expandIndexToRow( const QModelIndex& i
   if ( !model )
     return indexes;
 
-  for ( int column = 0; column < model->columnCount(); ++column )
+  int columns = model->columnCount();
+  indexes.reserve( columns );
+  for ( int column = 0; column < columns; ++column )
   {
     indexes.append( model->index( row, column ) );
   }
diff --git a/src/gui/auth/qgsauthauthoritieseditor.cpp b/src/gui/auth/qgsauthauthoritieseditor.cpp
index 00d3bb53794..71b1ed143a4 100644
--- a/src/gui/auth/qgsauthauthoritieseditor.cpp
+++ b/src/gui/auth/qgsauthauthoritieseditor.cpp
@@ -276,7 +276,7 @@ void QgsAuthAuthoritiesEditor::appendCertsToItem( QList<QSslCertificate> certs,
   QStringList untrustedids = mCertTrustCache.value( QgsAuthCertUtils::Untrusted );
 
   // Columns: Common Name, Serial #, Expiry Date
-  Q_FOREACH ( QSslCertificate cert, certs )
+  Q_FOREACH ( const QSslCertificate& cert, certs )
   {
     QString id( QgsAuthCertUtils::shaHexForCert( cert ) );
 
@@ -694,7 +694,7 @@ void QgsAuthAuthoritiesEditor::on_btnCaFile_clicked()
     if ( dlg->certTrustPolicy() != QgsAuthCertUtils::DefaultTrust )
     {
       QList<QSslCertificate> certs( QgsAuthManager::instance()->getExtraFileCAs() );
-      Q_FOREACH ( QSslCertificate cert, certs )
+      Q_FOREACH ( const QSslCertificate& cert, certs )
       {
         if ( !QgsAuthManager::instance()->storeCertTrustPolicy( cert, dlg->certTrustPolicy() ) )
         {
diff --git a/src/gui/auth/qgsauthcertificateinfo.cpp b/src/gui/auth/qgsauthcertificateinfo.cpp
index c01fce8527a..df0abd19fdb 100644
--- a/src/gui/auth/qgsauthcertificateinfo.cpp
+++ b/src/gui/auth/qgsauthcertificateinfo.cpp
@@ -774,7 +774,7 @@ void QgsAuthCertInfo::populateInfoDetailsSection()
   QStringList keyusage;
   QStringList extkeyusage;
   QList<QCA::ConstraintType> certconsts = mCurrentACert.constraints();
-  Q_FOREACH ( QCA::ConstraintType certconst, certconsts )
+  Q_FOREACH ( const QCA::ConstraintType& certconst, certconsts )
   {
     if ( certconst.section() == QCA::ConstraintType::KeyUsage )
     {
diff --git a/src/gui/auth/qgsauthidentitieseditor.cpp b/src/gui/auth/qgsauthidentitieseditor.cpp
index e0457865106..9273de091c3 100644
--- a/src/gui/auth/qgsauthidentitieseditor.cpp
+++ b/src/gui/auth/qgsauthidentitieseditor.cpp
@@ -195,7 +195,7 @@ void QgsAuthIdentitiesEditor::appendIdentitiesToItem( QList<QSslCertificate> cer
   QBrush redb( QgsAuthGuiUtils::redColor() );
 
   // Columns: Common Name, Serial #, Expiry Date
-  Q_FOREACH ( QSslCertificate cert, certs )
+  Q_FOREACH ( const QSslCertificate& cert, certs )
   {
     QString id( QgsAuthCertUtils::shaHexForCert( cert ) );
 
diff --git a/src/gui/auth/qgsauthimportidentitydialog.cpp b/src/gui/auth/qgsauthimportidentitydialog.cpp
index 894309cccd4..d7eb55cbf75 100644
--- a/src/gui/auth/qgsauthimportidentitydialog.cpp
+++ b/src/gui/auth/qgsauthimportidentitydialog.cpp
@@ -414,7 +414,7 @@ bool QgsAuthImportIdentityDialog::validatePkiPkcs12()
     QList<QSslCertificate> ca_certs;
     if ( cert_chain.size() > 1 )
     {
-      Q_FOREACH ( QCA::Certificate ca_cert, cert_chain )
+      Q_FOREACH ( const QCA::Certificate& ca_cert, cert_chain )
       {
         if ( ca_cert != cert_chain.primary() )
         {
diff --git a/src/gui/auth/qgsauthserverseditor.cpp b/src/gui/auth/qgsauthserverseditor.cpp
index f155cbd45a4..37203960d34 100644
--- a/src/gui/auth/qgsauthserverseditor.cpp
+++ b/src/gui/auth/qgsauthserverseditor.cpp
@@ -195,7 +195,7 @@ void QgsAuthServersEditor::appendSslConfigsToItem( QList<QgsAuthConfigSslServer>
   QBrush redb( QgsAuthGuiUtils::redColor() );
 
   // Columns: Common Name, Host, Expiry Date
-  Q_FOREACH ( QgsAuthConfigSslServer config, configs )
+  Q_FOREACH ( const QgsAuthConfigSslServer& config, configs )
   {
     QSslCertificate cert( config.sslCertificate() );
     QString id( QgsAuthCertUtils::shaHexForCert( cert ) );
diff --git a/src/gui/auth/qgsauthtrustedcasdialog.cpp b/src/gui/auth/qgsauthtrustedcasdialog.cpp
index 85eea121048..c9615165281 100644
--- a/src/gui/auth/qgsauthtrustedcasdialog.cpp
+++ b/src/gui/auth/qgsauthtrustedcasdialog.cpp
@@ -188,7 +188,7 @@ void QgsAuthTrustedCAsDialog::appendCertsToItem( QList<QSslCertificate> certs,
   QBrush redb( QgsAuthGuiUtils::redColor() );
 
   // Columns: Common Name, Serial #, Expiry Date
-  Q_FOREACH ( QSslCertificate cert, certs )
+  Q_FOREACH ( const QSslCertificate& cert, certs )
   {
     QString id( QgsAuthCertUtils::shaHexForCert( cert ) );
 
diff --git a/src/gui/editorwidgets/qgsrelationreferenceconfigdlg.cpp b/src/gui/editorwidgets/qgsrelationreferenceconfigdlg.cpp
index 46f7763cc51..25c47f20313 100644
--- a/src/gui/editorwidgets/qgsrelationreferenceconfigdlg.cpp
+++ b/src/gui/editorwidgets/qgsrelationreferenceconfigdlg.cpp
@@ -146,6 +146,7 @@ QgsEditorWidgetConfig QgsRelationReferenceConfigDlg::config()
   if ( mFilterGroupBox->isChecked() )
   {
     QStringList filterFields;
+    filterFields.reserve( mFilterFieldsList->count() );
     for ( int i = 0; i < mFilterFieldsList->count(); i++ )
     {
       filterFields << mFilterFieldsList->item( i )->data( Qt::UserRole ).toString();
diff --git a/src/gui/editorwidgets/qgsrelationreferencefactory.cpp b/src/gui/editorwidgets/qgsrelationreferencefactory.cpp
index 8f3b26d5fa9..1b7ed62e2a6 100644
--- a/src/gui/editorwidgets/qgsrelationreferencefactory.cpp
+++ b/src/gui/editorwidgets/qgsrelationreferencefactory.cpp
@@ -53,6 +53,7 @@ QgsEditorWidgetConfig QgsRelationReferenceFactory::readConfig( const QDomElement
   {
     QStringList filterFields;
     QDomNodeList fieldNodes = filterNode.toElement().elementsByTagName( "field" );
+    filterFields.reserve( fieldNodes.size() );
     for ( int i = 0; i < fieldNodes.size(); i++ )
     {
       QDomElement fieldElement = fieldNodes.at( i ).toElement();
diff --git a/src/gui/qgisgui.cpp b/src/gui/qgisgui.cpp
index b686f2284ce..fed9a1eb5a3 100644
--- a/src/gui/qgisgui.cpp
+++ b/src/gui/qgisgui.cpp
@@ -87,7 +87,7 @@ namespace QgisGui
   {
     // get a list of supported output image types
     QMap<QString, QString> filterMap;
-    Q_FOREACH ( QByteArray format, QImageWriter::supportedImageFormats() )
+    Q_FOREACH ( const QByteArray& format, QImageWriter::supportedImageFormats() )
     {
       //svg doesnt work so skip it
       if ( format ==  "svg" )
diff --git a/src/gui/qgscollapsiblegroupbox.cpp b/src/gui/qgscollapsiblegroupbox.cpp
index bb8657b4b41..ed636c7491b 100644
--- a/src/gui/qgscollapsiblegroupbox.cpp
+++ b/src/gui/qgscollapsiblegroupbox.cpp
@@ -274,7 +274,7 @@ void QgsCollapsibleGroupBoxBasic::toggleCollapsed()
       {
         if ( grpbox->syncGroup() == syncGroup() && grpbox->isEnabled() )
         {
-          if ( mShiftDown && grpbox == dynamic_cast<QgsCollapsibleGroupBoxBasic *>( this ) )
+          if ( mShiftDown && grpbox == this )
           {
             // expand current group box on shift-click
             setCollapsed( false );
diff --git a/src/gui/qgsdatadefinedbutton.cpp b/src/gui/qgsdatadefinedbutton.cpp
index 17dfe68b0ed..a6ed67f4521 100644
--- a/src/gui/qgsdatadefinedbutton.cpp
+++ b/src/gui/qgsdatadefinedbutton.cpp
@@ -643,6 +643,7 @@ void QgsDataDefinedButton::registerEnabledWidget( QWidget* wdgt )
 QList<QWidget*> QgsDataDefinedButton::registeredEnabledWidgets()
 {
   QList<QWidget*> wdgtList;
+  wdgtList.reserve( mEnabledWidgets.size() );
   for ( int i = 0; i < mEnabledWidgets.size(); ++i )
   {
     wdgtList << mEnabledWidgets.at( i );
@@ -678,6 +679,7 @@ void QgsDataDefinedButton::registerCheckedWidget( QWidget* wdgt )
 QList<QWidget*> QgsDataDefinedButton::registeredCheckedWidgets()
 {
   QList<QWidget*> wdgtList;
+  wdgtList.reserve( mCheckedWidgets.size() );
   for ( int i = 0; i < mCheckedWidgets.size(); ++i )
   {
     wdgtList << mCheckedWidgets.at( i );
diff --git a/src/gui/qgsexpressionbuilderwidget.cpp b/src/gui/qgsexpressionbuilderwidget.cpp
index be89cf1ee63..e6cdd34241d 100644
--- a/src/gui/qgsexpressionbuilderwidget.cpp
+++ b/src/gui/qgsexpressionbuilderwidget.cpp
@@ -285,6 +285,7 @@ void QgsExpressionBuilderWidget::loadFieldNames( const QgsFields& fields )
 
   QStringList fieldNames;
   //Q_FOREACH ( const QgsField& field, fields )
+  fieldNames.reserve( fields.count() );
   for ( int i = 0; i < fields.count(); ++i )
   {
     QString fieldName = fields[i].name();
diff --git a/src/gui/qgsmanageconnectionsdialog.cpp b/src/gui/qgsmanageconnectionsdialog.cpp
index 137666b6780..5b0c2395497 100644
--- a/src/gui/qgsmanageconnectionsdialog.cpp
+++ b/src/gui/qgsmanageconnectionsdialog.cpp
@@ -83,6 +83,7 @@ void QgsManageConnectionsDialog::doExportImport()
   }
 
   QStringList items;
+  items.reserve( selection.size() );
   for ( int i = 0; i < selection.size(); ++i )
   {
     items.append( selection.at( i )->text() );
diff --git a/src/gui/qgsmessagebar.cpp b/src/gui/qgsmessagebar.cpp
index 9431f51f6bd..5b1050799a2 100644
--- a/src/gui/qgsmessagebar.cpp
+++ b/src/gui/qgsmessagebar.cpp
@@ -130,7 +130,7 @@ void QgsMessageBar::popItem( QgsMessageBarItem *item )
   {
     if ( mCurrentItem )
     {
-      QWidget *widget = dynamic_cast<QWidget*>( mCurrentItem );
+      QWidget *widget = mCurrentItem;
       mLayout->removeWidget( widget );
       mCurrentItem->hide();
       disconnect( mCurrentItem, SIGNAL( styleChanged( QString ) ), this, SLOT( setStyleSheet( QString ) ) );
diff --git a/src/gui/qgsrasterlayersaveasdialog.cpp b/src/gui/qgsrasterlayersaveasdialog.cpp
index b138c2c6a5c..45a0e68b1ce 100644
--- a/src/gui/qgsrasterlayersaveasdialog.cpp
+++ b/src/gui/qgsrasterlayersaveasdialog.cpp
@@ -718,7 +718,9 @@ QgsRasterRangeList QgsRasterLayerSaveAsDialog::noData() const
   if ( ! mNoDataGroupBox->isChecked() )
     return noDataList;
 
-  for ( int r = 0 ; r < mNoDataTableWidget->rowCount(); r++ )
+  int rows = mNoDataTableWidget->rowCount();
+  noDataList.reserve( rows );
+  for ( int r = 0 ; r < rows; r++ )
   {
     QgsRasterRange noData( noDataCellValue( r, 0 ), noDataCellValue( r, 1 ) );
     noDataList.append( noData );
diff --git a/src/gui/qgsrelationmanagerdialog.cpp b/src/gui/qgsrelationmanagerdialog.cpp
index 9383f241c45..bb894f29a92 100644
--- a/src/gui/qgsrelationmanagerdialog.cpp
+++ b/src/gui/qgsrelationmanagerdialog.cpp
@@ -126,7 +126,9 @@ QList< QgsRelation > QgsRelationManagerDialog::relations()
 {
   QList< QgsRelation > relations;
 
-  for ( int i = 0; i < mRelationsTable->rowCount(); ++i )
+  int rows = mRelationsTable->rowCount();
+  relations.reserve( rows );
+  for ( int i = 0; i < rows; ++i )
   {
     QgsRelation relation = mRelationsTable->item( i, 0 )->data( Qt::UserRole ).value<QgsRelation>();
     // The name can be editted in the table, so apply this one
diff --git a/src/gui/raster/qgssinglebandpseudocolorrendererwidget.cpp b/src/gui/raster/qgssinglebandpseudocolorrendererwidget.cpp
index d1b3e732122..1b0e7e6c2d1 100644
--- a/src/gui/raster/qgssinglebandpseudocolorrendererwidget.cpp
+++ b/src/gui/raster/qgssinglebandpseudocolorrendererwidget.cpp
@@ -252,6 +252,7 @@ void QgsSingleBandPseudoColorRendererWidget::on_mClassifyButton_clicked()
     if ( colorRamp )
     {
       numberOfEntries = colorRamp->count();
+      entryValues.reserve( colorRamp->count() );
       for ( int i = 0; i < colorRamp->count(); ++i )
       {
         double value = colorRamp->value( i );
@@ -278,6 +279,7 @@ void QgsSingleBandPseudoColorRendererWidget::on_mClassifyButton_clicked()
       intervalDiff = max - min;
     }
 
+    entryValues.reserve( numberOfEntries );
     for ( int i = 0; i < numberOfEntries; ++i )
     {
       entryValues.push_back( currentValue );
@@ -309,6 +311,7 @@ void QgsSingleBandPseudoColorRendererWidget::on_mClassifyButton_clicked()
       colorDiff = ( int )( 255 / numberOfEntries );
     }
 
+    entryColors.reserve( numberOfEntries );
     for ( int i = 0; i < numberOfEntries; ++i )
     {
       QColor currentColor;
@@ -319,6 +322,7 @@ void QgsSingleBandPseudoColorRendererWidget::on_mClassifyButton_clicked()
   }
   else
   {
+    entryColors.reserve( numberOfEntries );
     for ( int i = 0; i < numberOfEntries; ++i )
     {
       int idx = mInvertCheckBox->isChecked() ? numberOfEntries - i - 1 : i;
diff --git a/src/gui/symbology-ng/qgscptcitycolorrampv2dialog.cpp b/src/gui/symbology-ng/qgscptcitycolorrampv2dialog.cpp
index 57340b45fab..20aa427640d 100644
--- a/src/gui/symbology-ng/qgscptcitycolorrampv2dialog.cpp
+++ b/src/gui/symbology-ng/qgscptcitycolorrampv2dialog.cpp
@@ -359,8 +359,7 @@ void QgsCptCityColorRampV2Dialog::on_pbtnLicenseDetails_pressed()
   QString path, title, copyFile, descFile;
 
   // get basic information, depending on if is color ramp or directory
-  QgsCptCityDataItem *item =
-    dynamic_cast< QgsCptCityDataItem* >( mModel->dataItem( mTreeFilter->mapToSource( mTreeView->currentIndex() ) ) );
+  QgsCptCityDataItem *item = mModel->dataItem( mTreeFilter->mapToSource( mTreeView->currentIndex() ) );
   if ( ! item )
     return;
 
diff --git a/src/gui/symbology-ng/qgsvectorgradientcolorrampv2dialog.cpp b/src/gui/symbology-ng/qgsvectorgradientcolorrampv2dialog.cpp
index 08732103d12..e8d2775b020 100644
--- a/src/gui/symbology-ng/qgsvectorgradientcolorrampv2dialog.cpp
+++ b/src/gui/symbology-ng/qgsvectorgradientcolorrampv2dialog.cpp
@@ -204,6 +204,7 @@ void QgsVectorGradientColorRampV2Dialog::updatePreview()
   if ( groupStops->isChecked() )
   {
     int count = treeStops->topLevelItemCount();
+    stops.reserve( count );
     for ( int i = 0; i < count; i++ )
     {
       QTreeWidgetItem* item = treeStops->topLevelItem( i );
diff --git a/src/plugins/geometry_checker/ui/qgsgeometrycheckerresulttab.cpp b/src/plugins/geometry_checker/ui/qgsgeometrycheckerresulttab.cpp
index 03dc6a66820..50f39a8f370 100644
--- a/src/plugins/geometry_checker/ui/qgsgeometrycheckerresulttab.cpp
+++ b/src/plugins/geometry_checker/ui/qgsgeometrycheckerresulttab.cpp
@@ -366,7 +366,7 @@ void QgsGeometryCheckerResultTab::highlightErrors( bool current )
   {
     double cx = 0., cy = 0.;
     QgsRectangle pointExtent( errorPositions.first(), errorPositions.first() );
-    foreach ( QgsPoint p, errorPositions )
+    foreach ( const QgsPoint& p, errorPositions )
     {
       cx += p.x();
       cy += p.y();
diff --git a/src/plugins/grass/qgsgrassmodule.cpp b/src/plugins/grass/qgsgrassmodule.cpp
index f5efcfd0400..e6c4a280b4d 100644
--- a/src/plugins/grass/qgsgrassmodule.cpp
+++ b/src/plugins/grass/qgsgrassmodule.cpp
@@ -105,7 +105,7 @@ QString QgsGrassModule::findExec( QString file )
 #endif
 
   // Search for module
-  foreach ( QString path, QgsGrass::grassModulesPaths() )
+  foreach ( const QString& path, QgsGrass::grassModulesPaths() )
   {
     QString full = path + "/" + file;
     if ( QFile::exists( full ) )
@@ -712,7 +712,7 @@ void QgsGrassModule::run()
 
       // Print some important variables
       variables << "QGIS_PREFIX_PATH" << "QGIS_GRASS_CRS" << "GRASS_REGION";
-      foreach ( QString v, variables )
+      foreach ( const QString& v, variables )
       {
         mOutputTextBrowser->append( v + "=" + environment.value( v ) + "<BR>" );
       }
diff --git a/src/plugins/grass/qgsgrassmoduleinput.cpp b/src/plugins/grass/qgsgrassmoduleinput.cpp
index d6386dcf333..ac15d62f733 100644
--- a/src/plugins/grass/qgsgrassmoduleinput.cpp
+++ b/src/plugins/grass/qgsgrassmoduleinput.cpp
@@ -95,7 +95,7 @@ void QgsGrassModuleInputModel::onDirectoryChanged( const QString & path )
       }
     }
 
-    foreach ( QString dirName, dirNames )
+    foreach ( const QString& dirName, dirNames )
     {
       // Add to watcher in any case, either for WIND, cellhd or vector
       QString dirPath = locationPath + "/" + dirName;
@@ -175,7 +175,7 @@ void QgsGrassModuleInputModel::refreshMapset( QStandardItem *mapsetItem, const Q
   {
     QStringList maps = QgsGrass::grassObjects( QgsGrass::getDefaultGisdbase() + "/" + QgsGrass::getDefaultLocation() + "/" + mapset, type );
     QStringList mapNames;
-    foreach ( QString map, maps )
+    foreach ( const QString& map, maps )
     {
       if ( map.startsWith( "qgis_import_tmp_" ) )
       {
@@ -237,7 +237,7 @@ void QgsGrassModuleInputModel::reload()
   mLocationPath = QgsGrass::getDefaultLocationPath();
 
   QStringList mapsets = QgsGrass::mapsets( QgsGrass::getDefaultGisdbase(), QgsGrass::getDefaultLocation() );
-  foreach ( QString mapset, mapsets )
+  foreach ( const QString& mapset, mapsets )
   {
     addMapset( mapset );
   }
@@ -246,7 +246,7 @@ void QgsGrassModuleInputModel::reload()
 
   // Watching all dirs in location because a dir may become a mapset later, when WIND is created
   QStringList dirNames = locationDirNames();
-  foreach ( QString dirName, dirNames )
+  foreach ( const QString& dirName, dirNames )
   {
     QString dirPath = mLocationPath + "/" + dirName;
     // Watch the dir in any case, WIND mabe created later
@@ -769,7 +769,7 @@ QgsGrassModuleInput::QgsGrassModuleInput( QgsGrassModule *module,
     {
       int mask = 0;
 
-      foreach ( QString typeName, opt.split( "," ) )
+      foreach ( const QString& typeName, opt.split( "," ) )
       {
         mask |= QgsGrass::vectorType( typeName );
       }
diff --git a/src/providers/grass/qgsgrass.cpp b/src/providers/grass/qgsgrass.cpp
index 4bab3e4e5cb..2b480d9bc78 100644
--- a/src/providers/grass/qgsgrass.cpp
+++ b/src/providers/grass/qgsgrass.cpp
@@ -1094,7 +1094,8 @@ QStringList QgsGrass::vectors( const QString& mapsetPath )
   QDir d = QDir( mapsetPath + "/vector" );
   d.setFilter( QDir::NoDotAndDotDot | QDir::Dirs );
 
-  for ( unsigned int i = 0; i < d.count(); i++ )
+  list.reserve( d.count() );
+  for ( unsigned int i = 0; i < d.count(); ++i )
   {
     /*
     if ( QFile::exists ( mapsetPath + "/vector/" + d[i] + "/head" ) )
@@ -1268,7 +1269,8 @@ QStringList QgsGrass::rasters( const QString& mapsetPath )
   QDir d = QDir( mapsetPath + "/cellhd" );
   d.setFilter( QDir::Files );
 
-  for ( unsigned int i = 0; i < d.count(); i++ )
+  list.reserve( d.count() );
+  for ( unsigned int i = 0; i < d.count(); ++i )
   {
     list.append( d[i] );
   }
@@ -1316,7 +1318,8 @@ QStringList QgsGrass::elements( const QString&  mapsetPath, const QString&  elem
     d.setFilter( QDir::Files );
   }
 
-  for ( unsigned int i = 0; i < d.count(); i++ )
+  list.reserve( d.count() );
+  for ( unsigned int i = 0; i < d.count(); ++i )
   {
     list.append( d[i] );
   }
@@ -1729,7 +1732,7 @@ QProcess *QgsGrass::startModule( const QString& gisdbase, const QString&  locati
   QString ownedMapset = mapset;
   if ( ownedMapset.isEmpty() )
   {
-    Q_FOREACH ( QString ms, mapsets( gisdbase, location ) )
+    Q_FOREACH ( const QString& ms, mapsets( gisdbase, location ) )
     {
       if ( isOwner( gisdbase, location, ms ) )
       {
@@ -2193,7 +2196,7 @@ void QgsGrass::insertRow( dbDriver *driver, const QString tableName,
   }
 
   QStringList valuesStringList;
-  foreach ( QVariant attribute, attributes )
+  foreach ( const QVariant& attribute, attributes )
   {
     QString valueString;
 
diff --git a/src/providers/grass/qgsgrassimport.cpp b/src/providers/grass/qgsgrassimport.cpp
index 86133c66212..1457981fc63 100644
--- a/src/providers/grass/qgsgrassimport.cpp
+++ b/src/providers/grass/qgsgrassimport.cpp
@@ -72,7 +72,7 @@ void QgsGrassImportProgress::onReadyReadStandardError()
   {
     // TODO: parse better progress output
     QString output = QString::fromLocal8Bit( mProcess->readAllStandardError() );
-    Q_FOREACH ( QString line, output.split( "\n" ) )
+    Q_FOREACH ( const QString& line, output.split( "\n" ) )
     {
       QgsDebugMsg( "line = '" + line + "'" );
       QString text, html;
@@ -500,7 +500,9 @@ QStringList QgsGrassRasterImport::extensions( QgsRasterDataProvider* provider )
   QStringList list;
   if ( provider && provider->bandCount() > 1 )
   {
-    for ( int band = 1; band <= provider->bandCount(); band++ )
+    int bands = provider->bandCount();
+    list.reserve( bands );
+    for ( int band = 1; band <= bands; ++band )
     {
       list << QString( ".%1" ).arg( band );
     }
@@ -513,7 +515,7 @@ QStringList QgsGrassRasterImport::names() const
   QStringList list;
   if ( mPipe && mPipe->provider() )
   {
-    foreach ( QString ext, extensions( mPipe->provider() ) )
+    foreach ( const QString& ext, extensions( mPipe->provider() ) )
     {
       list << mGrassObject.name() + ext;
     }
diff --git a/src/providers/grass/qgsgrassprovidermodule.cpp b/src/providers/grass/qgsgrassprovidermodule.cpp
index cac5c544532..4f883c701ed 100644
--- a/src/providers/grass/qgsgrassprovidermodule.cpp
+++ b/src/providers/grass/qgsgrassprovidermodule.cpp
@@ -328,7 +328,7 @@ QVector<QgsDataItem*>QgsGrassLocationItem::createChildren()
   QDir dir( mDirPath );
 
   QStringList entries = dir.entryList( QDir::Dirs | QDir::NoDotAndDotDot, QDir::Name );
-  foreach ( QString name, entries )
+  foreach ( const QString& name, entries )
   {
     QString path = dir.absoluteFilePath( name );
 
@@ -420,7 +420,7 @@ QVector<QgsDataItem*> QgsGrassMapsetItem::createChildren()
   QVector<QgsDataItem*> items;
 
   QStringList vectorNames = QgsGrass::vectors( mDirPath );
-  Q_FOREACH ( QString name, vectorNames )
+  Q_FOREACH ( const QString& name, vectorNames )
   {
     if ( mRefreshLater )
     {
@@ -509,7 +509,7 @@ QVector<QgsDataItem*> QgsGrassMapsetItem::createChildren()
       //map->setCapabilities( QgsDataItem::NoCapabilities ); // disable fertility
       map = new QgsGrassVectorItem( this, vectorObject, mapPath );
     }
-    foreach ( QString layerName, layerNames )
+    foreach ( const QString& layerName, layerNames )
     {
       // don't use QDir::separator(), windows work with '/' and backslash may be lost if
       // somewhere not properly escaped (there was bug in QgsMimeDataUtils for example)
@@ -548,7 +548,7 @@ QVector<QgsDataItem*> QgsGrassMapsetItem::createChildren()
 
   QStringList rasterNames = QgsGrass::rasters( mDirPath );
 
-  foreach ( QString name, rasterNames )
+  foreach ( const QString& name, rasterNames )
   {
     if ( mRefreshLater )
     {
@@ -571,7 +571,7 @@ QVector<QgsDataItem*> QgsGrassMapsetItem::createChildren()
   }
 
   QStringList groupNames = QgsGrass::groups( mDirPath );
-  foreach ( QString name, groupNames )
+  foreach ( const QString& name, groupNames )
   {
     if ( mRefreshLater )
     {
@@ -819,7 +819,7 @@ bool QgsGrassMapsetItem::handleDrop( const QMimeData * data, Qt::DropAction )
 
     // delete existing files (confirmed before in dialog)
     bool deleteOk = true;
-    foreach ( QString name, import->names() )
+    foreach ( const QString& name, import->names() )
     {
       QgsGrassObject obj( import->grassObject() );
       obj.setName( name );
diff --git a/src/providers/grass/qgsgrassrasterprovider.cpp b/src/providers/grass/qgsgrassrasterprovider.cpp
index 9c0c7b8bafe..9ddd0f82b59 100644
--- a/src/providers/grass/qgsgrassrasterprovider.cpp
+++ b/src/providers/grass/qgsgrassrasterprovider.cpp
@@ -587,7 +587,7 @@ QDateTime QgsGrassRasterProvider::dataTimestamp() const
   QString mapset = mGisdbase + "/" + mLocation + "/" + mMapset;
   QStringList dirs;
   dirs << "cell" << "colr";
-  foreach ( QString dir, dirs )
+  foreach ( const QString& dir, dirs )
   {
     QString path = mapset + "/" + dir + "/" + mMapName;
     QFileInfo fi( path );
diff --git a/src/providers/grass/qgsgrassvectormap.cpp b/src/providers/grass/qgsgrassvectormap.cpp
index 450d79a3609..cf82ad12f3f 100644
--- a/src/providers/grass/qgsgrassvectormap.cpp
+++ b/src/providers/grass/qgsgrassvectormap.cpp
@@ -613,6 +613,7 @@ QgsAbstractGeometryV2 * QgsGrassVectorMap::lineGeometry( int id )
 
   int type = Vect_read_line( mMap, points, 0, id );
   QList<QgsPointV2> pointList;
+  pointList.reserve( points->n_points );
   for ( int i = 0; i < points->n_points; i++ )
   {
     pointList << QgsPointV2( is3d() ? QgsWKBTypes::PointZ : QgsWKBTypes::Point, points->x[i], points->y[i], points->z[i] );
@@ -664,6 +665,7 @@ QgsAbstractGeometryV2 * QgsGrassVectorMap::areaGeometry( int id )
   Vect_get_area_points( mMap, id, points );
 
   QList<QgsPointV2> pointList;
+  pointList.reserve( points->n_points );
   for ( int i = 0; i < points->n_points; i++ )
   {
     pointList << QgsPointV2( is3d() ? QgsWKBTypes::PointZ : QgsWKBTypes::Point, points->x[i], points->y[i], points->z[i] );
@@ -680,6 +682,7 @@ QgsAbstractGeometryV2 * QgsGrassVectorMap::areaGeometry( int id )
     int isle = Vect_get_area_isle( mMap, id, i );
     Vect_get_isle_points( mMap, isle, points );
 
+    pointList.reserve( points->n_points );
     for ( int i = 0; i < points->n_points; i++ )
     {
       pointList <<  QgsPointV2( is3d() ? QgsWKBTypes::PointZ : QgsWKBTypes::Point, points->x[i], points->y[i], points->z[i] );
diff --git a/src/providers/grass/qgsgrassvectormaplayer.cpp b/src/providers/grass/qgsgrassvectormaplayer.cpp
index 2a7a87b9770..8bff3a93798 100644
--- a/src/providers/grass/qgsgrassvectormaplayer.cpp
+++ b/src/providers/grass/qgsgrassvectormaplayer.cpp
@@ -746,7 +746,7 @@ void QgsGrassVectorMapLayer::deleteColumn( const QgsField &field, QString &error
     queries << QString( "CREATE UNIQUE INDEX %1_%2 ON %1 (%2)" ).arg( mFieldInfo->table ).arg( mFieldInfo->key );
     queries << "COMMIT";
     // Execute one after another to get possible error
-    Q_FOREACH ( QString query, queries )
+    Q_FOREACH ( const QString& query, queries )
     {
       QgsDebugMsg( "query = " + query );
       executeSql( query, error );
@@ -832,7 +832,8 @@ void QgsGrassVectorMapLayer::insertAttributes( int cat, const QgsFeature &featur
     if ( error.isEmpty() )
     {
       QList<QVariant> values;
-      for ( int i = 0; i < mAttributeFields.size(); i++ )
+      values.reserve( mAttributeFields.size() );
+      for ( int i = 0; i < mAttributeFields.size(); ++i )
       {
         values << QVariant();
       }
diff --git a/src/providers/ogr/qgsogrdataitems.cpp b/src/providers/ogr/qgsogrdataitems.cpp
index b40b119c544..caa9d136245 100644
--- a/src/providers/ogr/qgsogrdataitems.cpp
+++ b/src/providers/ogr/qgsogrdataitems.cpp
@@ -198,7 +198,8 @@ QVector<QgsDataItem*> QgsOgrDataCollectionItem::createChildren()
     return children;
   int numLayers = OGR_DS_GetLayerCount( hDataSource );
 
-  for ( int i = 0; i < numLayers; i++ )
+  children.reserve( numLayers );
+  for ( int i = 0; i < numLayers; ++i )
   {
     QgsOgrLayerItem* item = dataItemForLayer( this, QString(), mPath, hDataSource, i );
     children.append( item );
diff --git a/src/providers/postgres/qgspostgresconn.cpp b/src/providers/postgres/qgspostgresconn.cpp
index 45dda1a97b8..7544f09ad69 100644
--- a/src/providers/postgres/qgspostgresconn.cpp
+++ b/src/providers/postgres/qgspostgresconn.cpp
@@ -1087,6 +1087,7 @@ PGresult *QgsPostgresConn::PQexecPrepared( QString stmtName, const QStringList &
   const char **param = new const char *[ params.size()];
   QList<QByteArray> qparam;
 
+  qparam.reserve( params.size() );
   for ( int i = 0; i < params.size(); i++ )
   {
     qparam << params[i].toUtf8();
diff --git a/src/providers/postgres/qgspostgresprovider.cpp b/src/providers/postgres/qgspostgresprovider.cpp
index 3689b49de44..2b113fbbf3d 100644
--- a/src/providers/postgres/qgspostgresprovider.cpp
+++ b/src/providers/postgres/qgspostgresprovider.cpp
@@ -1847,6 +1847,7 @@ bool QgsPostgresProvider::addFeatures( QgsFeatureList &flist )
         appendGeomParam( features->constGeometry(), params );
       }
 
+      params.reserve( fieldId.size() );
       for ( int i = 0; i < fieldId.size(); i++ )
       {
         int attrIdx = fieldId[i];
@@ -2432,6 +2433,7 @@ bool QgsPostgresProvider::changeGeometryValues( QgsGeometryMap & geometry_map )
 QgsAttributeList QgsPostgresProvider::attributeIndexes()
 {
   QgsAttributeList lst;
+  lst.reserve( mAttributeFields.count() );
   for ( int i = 0; i < mAttributeFields.count(); ++i )
     lst.append( i );
   return lst;
diff --git a/src/providers/wms/qgswmsprovider.cpp b/src/providers/wms/qgswmsprovider.cpp
index 82770af0435..42fb900e712 100644
--- a/src/providers/wms/qgswmsprovider.cpp
+++ b/src/providers/wms/qgswmsprovider.cpp
@@ -3101,7 +3101,7 @@ void QgsWmsProvider::getLegendGraphicReplyFinished( const QImage& img )
   if ( ! img.isNull() )
   {
     mGetLegendGraphicImage = img;
-    mGetLegendGraphicExtent = QgsRectangle( reply->property( "legendExtent" ).value<QRectF>() );
+    mGetLegendGraphicExtent = QgsRectangle( reply->property( "legendExtent" ).toRectF() );
     mGetLegendGraphicScale = reply->property( "legendScale" ).value<double>();
 
 #ifdef QGISDEBUG