diff --git a/src/ifcgeom/mapping/IfcIndexedPolyCurve.cpp b/src/ifcgeom/mapping/IfcIndexedPolyCurve.cpp
index c0ceac76d8..535ec89aaa 100644
--- a/src/ifcgeom/mapping/IfcIndexedPolyCurve.cpp
+++ b/src/ifcgeom/mapping/IfcIndexedPolyCurve.cpp
@@ -47,9 +47,9 @@ taxonomy::ptr mapping::map_impl(const IfcSchema::IfcIndexedPolyCurve* inst) {
 	auto loop = taxonomy::make<taxonomy::loop>();
 
 	if(inst->Segments()) {
-		aggregate_of_instance::ptr segments = *inst->Segments();
-		for (aggregate_of_instance::it it = segments->begin(); it != segments->end(); ++it) {
-			IfcUtil::IfcBaseClass* segment = *it;
+		auto segments = *inst->Segments();
+		for (auto it = segments->begin(); it != segments->end(); ++it) {
+			auto segment = *it;
 			if (segment->declaration().is(IfcSchema::IfcLineIndex::Class())) {
 				IfcSchema::IfcLineIndex* line = (IfcSchema::IfcLineIndex*) segment;
 				std::vector<int> indices = *line;
diff --git a/src/ifcgeom/mapping/IfcTrimmedCurve.cpp b/src/ifcgeom/mapping/IfcTrimmedCurve.cpp
index 608e945db8..22b8c5e4bb 100644
--- a/src/ifcgeom/mapping/IfcTrimmedCurve.cpp
+++ b/src/ifcgeom/mapping/IfcTrimmedCurve.cpp
@@ -34,8 +34,8 @@ taxonomy::ptr mapping::map_impl(const IfcSchema::IfcTrimmedCurve* inst) {
 	tc->basis = map(inst->BasisCurve());
 	
 	bool trim_cartesian = inst->MasterRepresentation() != IfcSchema::IfcTrimmingPreference::IfcTrimmingPreference_PARAMETER;
-	aggregate_of_instance::ptr trims1 = inst->Trim1();
-	aggregate_of_instance::ptr trims2 = inst->Trim2();
+	auto trims1 = inst->Trim1();
+	auto trims2 = inst->Trim2();
 	
 	// reversed orientation handling happens in geometry kernel
 	unsigned sense_agreement = 0;
@@ -46,8 +46,8 @@ taxonomy::ptr mapping::map_impl(const IfcSchema::IfcTrimmedCurve* inst) {
 	
 	tc->orientation = inst->SenseAgreement();
 
-	for ( aggregate_of_instance::it it = trims1->begin(); it != trims1->end(); it ++ ) {
-		IfcUtil::IfcBaseClass* i = *it;
+	for (auto it = trims1->begin(); it != trims1->end(); it ++) {
+		auto i = *it;
 		if ( i->declaration().is(IfcSchema::IfcCartesianPoint::Class()) ) {
 			pnts[sense_agreement] = taxonomy::cast<taxonomy::point3>(map(i));
 			has_pnts[sense_agreement] = true;
@@ -58,8 +58,8 @@ taxonomy::ptr mapping::map_impl(const IfcSchema::IfcTrimmedCurve* inst) {
 		}
 	}
 
-	for ( aggregate_of_instance::it it = trims2->begin(); it != trims2->end(); it ++ ) {
-		IfcUtil::IfcBaseClass* i = *it;
+	for (auto it = trims2->begin(); it != trims2->end(); it ++) {
+		auto i = *it;
 		if ( i->declaration().is(IfcSchema::IfcCartesianPoint::Class()) ) {
 			pnts[1 - sense_agreement] = taxonomy::cast<taxonomy::point3>(map(i));
 			has_pnts[1-sense_agreement] = true;
diff --git a/src/ifcgeom/mapping/mapping.cpp b/src/ifcgeom/mapping/mapping.cpp
index 304dc22793..7a98125191 100644
--- a/src/ifcgeom/mapping/mapping.cpp
+++ b/src/ifcgeom/mapping/mapping.cpp
@@ -318,8 +318,8 @@ namespace {
 	template <typename T>
 	std::pair<IfcSchema::IfcSurfaceStyle*, T*> get_surface_style(const IfcSchema::IfcStyledItem* si) {
 #ifdef SCHEMA_HAS_IfcStyleAssignmentSelect
-		aggregate_of_instance::ptr style_assignments = si->Styles();
-		for (aggregate_of_instance::it kt = style_assignments->begin(); kt != style_assignments->end(); ++kt) {
+		auto style_assignments = si->Styles();
+		for (auto kt = style_assignments->begin(); kt != style_assignments->end(); ++kt) {
 			if (!(*kt)->declaration().is(IfcSchema::IfcPresentationStyleAssignment::Class())) {
 				continue;
 			}
@@ -338,12 +338,12 @@ namespace {
 		auto styles = si->Styles();
 #endif
 			for (auto lt = styles->begin(); lt != styles->end(); ++lt) {
-				IfcUtil::IfcBaseClass* style = *lt;
+				auto style = *lt;
 				if (style->declaration().is(IfcSchema::IfcSurfaceStyle::Class())) {
 					IfcSchema::IfcSurfaceStyle* surface_style = (IfcSchema::IfcSurfaceStyle*) style;
 					if (surface_style->Side() != IfcSchema::IfcSurfaceSide::IfcSurfaceSide_NEGATIVE) {
-						aggregate_of_instance::ptr styles_elements = surface_style->Styles();
-						for (aggregate_of_instance::it mt = styles_elements->begin(); mt != styles_elements->end(); ++mt) {
+						auto styles_elements = surface_style->Styles();
+						for (auto mt = styles_elements->begin(); mt != styles_elements->end(); ++mt) {
 							if ((*mt)->declaration().is(T::Class())) {
 								return std::make_pair(surface_style, (T*)*mt);
 							}
@@ -596,12 +596,12 @@ void mapping::initialize_units_() {
 	bool length_unit_encountered = false, angle_unit_encountered = false;
 
 	try {
-		aggregate_of_instance::ptr units = unit_assignment->Units();
+		auto units = unit_assignment->Units();
 		if (!units || !units->size()) {
 			Logger::Warning("No unit information found");
 		} else {
-			for (aggregate_of_instance::it it = units->begin(); it != units->end(); ++it) {
-				IfcUtil::IfcBaseClass* base = *it;
+			for (auto it = units->begin(); it != units->end(); ++it) {
+				IfcSchema::IfcUnit* base = *it;
 				if (base->declaration().is(IfcSchema::IfcNamedUnit::Class())) {
 					IfcSchema::IfcNamedUnit* named_unit = base->as<IfcSchema::IfcNamedUnit>();
 					if (named_unit->UnitType() == IfcSchema::IfcUnitEnum::IfcUnit_LENGTHUNIT ||
diff --git a/src/serializers/schema_dependent/XmlSerializer.cpp b/src/serializers/schema_dependent/XmlSerializer.cpp
index 3d7236d51f..7cb7de8237 100644
--- a/src/serializers/schema_dependent/XmlSerializer.cpp
+++ b/src/serializers/schema_dependent/XmlSerializer.cpp
@@ -746,8 +746,8 @@ void POSTFIX_SCHEMA(XmlSerializer)::finalize() {
 	}
 
 	// Write all assigned units as XML nodes.
-	aggregate_of_instance::ptr unit_assignments = project->UnitsInContext()->Units();
-	for (aggregate_of_instance::it it = unit_assignments->begin(); it != unit_assignments->end(); ++it) {
+	auto unit_assignments = project->UnitsInContext()->Units();
+	for (auto it = unit_assignments->begin(); it != unit_assignments->end(); ++it) {
 		if ((*it)->declaration().is(IfcSchema::IfcNamedUnit::Class())) {
 			IfcSchema::IfcNamedUnit* named_unit = (*it)->as<IfcSchema::IfcNamedUnit>();
 			ptree* node = format_entity_instance(mapping_, named_unit, units);