Work on runtime representation of schema

src/ifcparse/IfcFile.h

@@ -41,6 +41,8 @@ public:
 private:
 	typedef std::map<IfcUtil::IfcBaseClass*, IfcUtil::IfcBaseClass*> entity_entity_map_t;
 
+	const schema_definition* schema_;
+
 	bool _create_latebound_entities;
 
 	entity_by_id_t byid;
@@ -131,6 +133,8 @@ public:
 	bool create_latebound_entities() const { return _create_latebound_entities; }
 
 	std::pair<IfcSchema::IfcNamedUnit*, double> getUnit(IfcSchema::IfcUnitEnum::IfcUnitEnum);
+
+	const schema_definition* schema() const { return schema_; }
 };
 
 }

src/ifcparse/IfcHierarchyHelper.cpp

@@ -124,7 +124,7 @@ IfcSchema::IfcProject* IfcHierarchyHelper::addProject(IfcSchema::IfcOwnerHistory
 
 void IfcHierarchyHelper::relatePlacements(IfcSchema::IfcProduct* parent, IfcSchema::IfcProduct* product) {
 	IfcSchema::IfcObjectPlacement* place = product->hasObjectPlacement() ? product->ObjectPlacement() : 0;
-	if (place && place->is(IfcSchema::Type::IfcLocalPlacement)) {
+	if (place && place->declaration().is(IfcSchema::Type::IfcLocalPlacement)) {
 		IfcSchema::IfcLocalPlacement* local_place = (IfcSchema::IfcLocalPlacement*) place;
 		if (parent->hasObjectPlacement()) {
 			local_place->setPlacementRelTo(parent->ObjectPlacement());

src/ifcparse/IfcLateBoundEntity.cpp

@@ -36,10 +36,10 @@ using namespace IfcUtil;
 
 IfcWrite::IfcWritableEntity* IfcParse::IfcLateBoundEntity::writable_entity() {
 	IfcWrite::IfcWritableEntity* e;
-	if (entity->isWritable()) {
-		e = (IfcWrite::IfcWritableEntity*) entity;
+	if (data_->isWritable()) {
+		e = (IfcWrite::IfcWritableEntity*) data_;
 	} else {
-		entity = e = new IfcWrite::IfcWritableEntity(entity);
+		data_ = e = new IfcWrite::IfcWritableEntity(data_);
 	}
 	return e;
 }
@@ -47,20 +47,25 @@ IfcParse::IfcLateBoundEntity::IfcLateBoundEntity(const std::string& s) {
 	std::string S = s;
 	for (std::string::iterator i = S.begin(); i != S.end(); ++i ) *i = toupper(*i);
 	_type = IfcSchema::Type::FromString(S);
-	entity = new IfcWrite::IfcWritableEntity(_type);
+	data_ = new IfcWrite::IfcWritableEntity(_type);
 	for (unsigned i = 0; i < getArgumentCount(); ++i) {
 		// Side effect of this is that a NULL attribute is created.
-		entity->getArgument(i);
+		data_->getArgument(i);
 	}
 	IfcSchema::Type::PopulateDerivedFields(writable_entity());
 }
 IfcParse::IfcLateBoundEntity::IfcLateBoundEntity(IfcAbstractEntity* e) {
-	entity = e;
+	data_ = e;
 	_type = e->type();
 }
+/*
+const IfcParse::entity& IfcParse::IfcLateBoundEntity::entity() {
+	return *get_schema().declaration_by_name(IfcSchema::Type::ToString(_type));
+}
+*/
 unsigned int IfcParse::IfcLateBoundEntity::id() const {
-	if (entity->file) {
-		return static_cast<unsigned int>(entity->id());
+	if (data_->file) {
+		return static_cast<unsigned int>(data_->id());
 	} else {
 		throw IfcException("Entity not bound to a file");
 	}
@@ -97,7 +102,7 @@ IfcSchema::Type::Enum IfcParse::IfcLateBoundEntity::getArgumentEntity(unsigned i
 	return IfcSchema::Type::GetAttributeEntity(_type, i);
 }
 Argument* IfcParse::IfcLateBoundEntity::getArgument(unsigned int i) const {
-	return entity->getArgument(i);
+	return data_->getArgument(i);
 }
 const char* IfcParse::IfcLateBoundEntity::getArgumentName(unsigned int i) const {
 	return IfcSchema::Type::GetAttributeName(_type,i).c_str();
@@ -215,11 +220,11 @@ unsigned IfcParse::IfcLateBoundEntity::getArgumentIndex(const std::string& a) co
 	return IfcSchema::Type::GetAttributeIndex(_type,a);
 }
 std::string IfcParse::IfcLateBoundEntity::toString() {
-	return entity->toString(false);
+	return data_->toString(false);
 }
 IfcEntityList::ptr IfcParse::IfcLateBoundEntity::get_inverse(const std::string& a) {
 	std::pair<IfcSchema::Type::Enum, unsigned> inv = IfcSchema::Type::GetInverseAttribute(_type, a);
-	return entity->getInverse(inv.first, inv.second);
+	return data_->getInverse(inv.first, inv.second);
 }		
 bool IfcParse::IfcLateBoundEntity::is_valid() {
 	const unsigned arg_count = getArgumentCount();

src/ifcparse/IfcLateBoundEntity.h

@@ -32,7 +32,7 @@ namespace IfcParse {
 	// that in the IfcFile class the distinction what entity type to be created is 
 	// no longer necessary and weird diagonal casts when creating geometry from
 	// IfcLateBoundEntities are eliminated.
-	class IfcLateBoundEntity : public IfcUtil::IfcBaseEntity {
+	class IfcLateBoundEntity : public IfcUtil::IfcBaseClass { // TODO: -Entity or -Type?
 	private:
 		IfcSchema::Type::Enum _type;
 		IfcWrite::IfcWritableEntity* writable_entity();
@@ -79,6 +79,20 @@ namespace IfcParse {
 		std::string toString();
 
 		bool is_valid();
+
+		// const IfcParse::entity& entity();
+		
+		const IfcAbstractEntity& data() const { return *data_; }
+		IfcAbstractEntity& data() { return *data_; }
+
+		virtual const IfcParse::declaration& declaration() const {
+			if (data().file) {
+				throw;
+				// data().file->
+			} else {
+				throw;
+			}
+		}
 	};
 
 }

src/ifcparse/IfcParse.cpp

@@ -37,6 +37,7 @@
 #include "../ifcparse/IfcLateBoundEntity.h"
 #include "../ifcparse/IfcFile.h"
 #include "../ifcparse/IfcSIPrefix.h"
+#include "../ifcparse/IfcSchema.h"
 
 using namespace IfcParse;
 
@@ -764,7 +765,7 @@ EntityArgument::operator IfcEntityListList::ptr() const { throw IfcException("Ar
 unsigned int EntityArgument::size() const { return 1; }
 Argument* EntityArgument::operator [] (unsigned int i) const { throw IfcException("Argument is not a list of arguments"); }
 std::string EntityArgument::toString(bool upper) const { 
-	return entity->entity->toString(upper);
+	return entity->data().toString(upper);
 }
 //return entity->entity->toString(); }
 bool EntityArgument::isNull() const { return false; }
@@ -879,11 +880,10 @@ IfcEntityList::ptr Entity::getInverse(IfcSchema::Type::Enum type, int attribute_
 }
 
 bool Entity::is(IfcSchema::Type::Enum v) const { return _type == v; }
-unsigned int Entity::id() { return _id; }
+unsigned int Entity::id() const { return _id; }
 
-IfcWrite::IfcWritableEntity* Entity::isWritable() {
-	return 0;
-}
+const IfcWrite::IfcWritableEntity* Entity::isWritable() const { return 0; }
+IfcWrite::IfcWritableEntity* Entity::isWritable() { return 0; }
 
 IfcFile::IfcFile(bool create_latebound_entities)
 	: _create_latebound_entities(create_latebound_entities)
@@ -892,6 +892,9 @@ IfcFile::IfcFile(bool create_latebound_entities)
 	, tokens(0)
 	, MaxId(0)
 {
+	if (!create_latebound_entities) {
+		schema_ = &get_schema();
+	}
 	setDefaultHeaderValues();
 }
 
@@ -961,7 +964,7 @@ bool IfcFile::Init(IfcParse::IfcSpfStream* s) {
 				std::stringstream ss; ss << "\r#" << currentId;
 				Logger::Status(ss.str(), false);
 			}
-			if ( entity->is(IfcSchema::Type::IfcRoot) ) {
+			if ( entity->declaration().is(IfcSchema::Type::IfcRoot) ) {
 				IfcSchema::IfcRoot* ifc_root = (IfcSchema::IfcRoot*) entity;
 				try {
 					const std::string guid = ifc_root->GlobalId();
@@ -976,7 +979,7 @@ bool IfcFile::Init(IfcParse::IfcSpfStream* s) {
 				}
 			}
 
-			IfcSchema::Type::Enum ty = entity->type();
+			IfcSchema::Type::Enum ty = entity->declaration().type();
 			do {
 				IfcEntityList::ptr instances_by_type = entitiesByType(ty);
 				if (!instances_by_type) {
@@ -1031,8 +1034,9 @@ void IfcFile::traverse(IfcUtil::IfcBaseClass* instance, std::set<IfcUtil::IfcBas
 
 	if (level >= max_level && max_level > 0) return;
 
-	for (unsigned i = 0; i < instance->getArgumentCount(); ++i) {
-		Argument* arg = instance->getArgument(i);
+	auto attributes = instance->declaration().as_entity()->all_attributes();
+	for (unsigned i = 0; i < attributes.size(); ++i) {
+		Argument* arg = instance->data().getArgument(i);
 
 		if (arg->type() == IfcUtil::Argument_ENTITY_INSTANCE) {
 			traverse(*arg, visited, list, level + 1, max_level);
@@ -1065,10 +1069,10 @@ void IfcFile::addEntities(IfcEntityList::ptr es) {
 	}
 }
 
-IfcUtil::IfcBaseClass* IfcFile::addEntity(IfcUtil::IfcBaseClass* entity) {
+IfcUtil::IfcBaseClass* IfcFile::addEntity(IfcUtil::IfcBaseClass* instance) {
 	// If this instance has been inserted before, return
 	// a reference to the copy that was created from it.
-	entity_entity_map_t::iterator it = entity_file_map.find(entity);
+	entity_entity_map_t::iterator it = entity_file_map.find(instance);
 	if (it != entity_file_map.end()) {
 		return it->second;
 	}
@@ -1076,39 +1080,44 @@ IfcUtil::IfcBaseClass* IfcFile::addEntity(IfcUtil::IfcBaseClass* entity) {
 	// Obtain all forward references by a depth-first 
 	// traversal and add them to the file.
 	try {
-		IfcEntityList::ptr entity_attributes = traverse(entity, 1);
+		IfcEntityList::ptr entity_attributes = traverse(instance, 1);
 		for (IfcEntityList::it it = entity_attributes->begin(); it != entity_attributes->end(); ++it) {
-			if (*it != entity) {
+			if (*it != instance) {
 				entity_file_map.insert(entity_entity_map_t::value_type(*it, addEntity(*it)));
 			}
 		}
 	} catch (...) {
-		Logger::Message(Logger::LOG_ERROR, "Failed to visit forward references of", entity->entity);
+		Logger::Message(Logger::LOG_ERROR, "Failed to visit forward references of", instance);
 	}
 
 	// See whether the instance is already part of a file
-	if (entity->entity->file != 0) {
-		if (entity->entity->file == this) {
+	if (instance->data().file != 0) {
+		if (instance->data().file == this) {
 			// If it is part of this file
 			// nothing needs to be done.
-			return entity;
+			return instance;
 		}
 
 		// An instance is being added from another file. A copy of the
-		// container and entity is created. The attribute references 
+		// container and instance is created. The attribute references 
 		// need to be updated to point to instances in this file.
-		IfcFile* other_file = entity->entity->file;
-		IfcWrite::IfcWritableEntity* we = new IfcWrite::IfcWritableEntity(entity->entity);
+		IfcFile* other_file = instance->data().file;
+		
+		// TODO: Proper copy constructor
+		IfcWrite::IfcWritableEntity* we = new IfcWrite::IfcWritableEntity(&instance->data());
+		
 		if (this->create_latebound_entities()) {
-			entity = new IfcLateBoundEntity(we);
+			instance = new IfcLateBoundEntity(we);
 		} else {
-			entity = IfcSchema::SchemaEntity(we);
+			instance = IfcSchema::SchemaEntity(we);
 		}
 		
-		// In case an entity is added that contains geometry, the unit
+		// In case an instance is added that contains geometry, the unit
 		// information needs to be accounted for for IfcLengthMeasures.
 		boost::optional<double> conversion_factor;
 
+		const schema_definition* s = schema();
+		
 		for (unsigned i = 0; i < we->getArgumentCount(); ++i) {
 			Argument* attr = we->getArgument(i);
 			IfcUtil::ArgumentType attr_type = attr->type();
@@ -1138,23 +1147,31 @@ IfcUtil::IfcBaseClass* IfcFile::addEntity(IfcUtil::IfcBaseClass* entity) {
 					new_instances->push(list);
 				}
 				we->setArgument(i, new_instances);
-			} else if (entity->getArgumentEntity(i) == IfcSchema::Type::IfcLengthMeasure ||
-				entity->getArgumentEntity(i) == IfcSchema::Type::IfcPositiveLengthMeasure) 
-			{
-				if (!conversion_factor) {
-					conversion_factor = other_file->getUnit(IfcSchema::IfcUnitEnum::IfcUnit_LENGTHUNIT).second / 
-						getUnit(IfcSchema::IfcUnitEnum::IfcUnit_LENGTHUNIT).second;
-				}
-				if (attr_type == IfcUtil::Argument_DOUBLE) {
-					double v = *attr;
-					v *= *conversion_factor;
-					we->setArgument(i, v);
-				} else if (attr_type == IfcUtil::Argument_AGGREGATE_OF_DOUBLE) {
-					std::vector<double> v = *attr;
-					for (std::vector<double>::iterator it = v.begin(); it != v.end(); ++it) {
-						(*it) *= *conversion_factor;
+			} else if (s) {
+				const entity* e = instance->declaration().as_entity();
+				if (e) {
+					const std::vector<const entity::attribute*> attrs = e->all_attributes();
+					const parameter_type* pt = attrs[i]->type_of_attribute();
+					while (pt->as_aggregation_type()) {
+						pt = pt->as_aggregation_type()->type_of_element();
+					}
+					if (pt->is(IfcSchema::Type::IfcLengthMeasure)) {
+						if (!conversion_factor) {
+							conversion_factor = other_file->getUnit(IfcSchema::IfcUnitEnum::IfcUnit_LENGTHUNIT).second / 
+								getUnit(IfcSchema::IfcUnitEnum::IfcUnit_LENGTHUNIT).second;
+						}
+						if (attr_type == IfcUtil::Argument_DOUBLE) {
+							double v = *attr;
+							v *= *conversion_factor;
+							we->setArgument(i, v);
+						} else if (attr_type == IfcUtil::Argument_AGGREGATE_OF_DOUBLE) {
+							std::vector<double> v = *attr;
+							for (std::vector<double>::iterator it = v.begin(); it != v.end(); ++it) {
+								(*it) *= *conversion_factor;
+							}
+							we->setArgument(i, v);
+						}
 					}
-					we->setArgument(i, v);
 				}
 			}
 		}
@@ -1166,13 +1183,13 @@ IfcUtil::IfcBaseClass* IfcFile::addEntity(IfcUtil::IfcBaseClass* entity) {
 	}
 
 	// For subtypes of IfcRoot, the GUID mapping needs to be updated.
-	if (entity->is(IfcSchema::Type::IfcRoot)) {
-		IfcSchema::IfcRoot* ifc_root = (IfcSchema::IfcRoot*) entity;
+	if (instance->declaration().is(IfcSchema::Type::IfcRoot)) {
+		IfcSchema::IfcRoot* ifc_root = (IfcSchema::IfcRoot*) instance;
 		try {
 			const std::string guid = ifc_root->GlobalId();
 			if ( byguid.find(guid) != byguid.end() ) {
 				std::stringstream ss;
-				ss << "Overwriting entity with guid " << guid;
+				ss << "Overwriting instance with guid " << guid;
 				Logger::Message(Logger::LOG_WARNING,ss.str());
 			}
 			byguid[guid] = ifc_root;
@@ -1181,74 +1198,75 @@ IfcUtil::IfcBaseClass* IfcFile::addEntity(IfcUtil::IfcBaseClass* entity) {
 		}
 	}
 
-	// The mapping by entity type is updated.
-	IfcSchema::Type::Enum ty = entity->type();
+	// The mapping by instance type is updated.
+	IfcSchema::Type::Enum ty = instance->declaration().type();
 	do {
 		IfcEntityList::ptr instances_by_type = entitiesByType(ty);
 		if (!instances_by_type) {
 			instances_by_type = IfcEntityList::ptr(new IfcEntityList());
 			bytype[ty] = instances_by_type;
 		}
-		instances_by_type->push(entity);
+		instances_by_type->push(instance);
 		ty = IfcSchema::Type::Parent(ty);
 	} while ( ty > -1 );
 	
 	int new_id = -1;
-	if (entity->entity->isWritable() && !entity->entity->file) {
+	if (instance->data().isWritable() && !instance->data().file) {
 		// For newly created entities ensure a valid ENTITY_INSTANCE_NAME is set
-		entity->entity->file = this;
-		new_id = entity->entity->isWritable()->setId();
+		instance->data().file = this;
+		new_id = instance->data().isWritable()->setId();
 	} else {
-		new_id = entity->entity->id();
+		new_id = instance->data().id();
 	}
 
 	if (byid.find(new_id) != byid.end()) {
 		// This should not happen
 		std::stringstream ss;
-		ss << "Overwriting entity with id " << new_id;
+		ss << "Overwriting instance with id " << new_id;
 		Logger::Message(Logger::LOG_WARNING, ss.str());
 	}
 
 	// The mapping by entity instance name is updated.
-	byid[new_id] = entity;
+	byid[new_id] = instance;
 
 	// The mapping by reference is updated.
 	IfcEntityList::ptr entity_attributes(new IfcEntityList);
 	try {
-		entity_attributes = traverse(entity, 1);
+		entity_attributes = traverse(instance, 1);
 	} catch (...) {}
 	for (IfcEntityList::it it = entity_attributes->begin(); it != entity_attributes->end(); ++it) {
 		IfcUtil::IfcBaseClass* entity_attribute = *it;
-		if (*it == entity) continue;
+		if (*it == instance) continue;
 		try {
-			if (!IfcSchema::Type::IsSimple(entity_attribute->type())) {
-				unsigned entity_attribute_id = entity_attribute->entity->id();
+			// if (!IfcSchema::Type::IsSimple(entity_attribute->type())) {
+			if (!entity_attribute->declaration().as_entity()) {
+				unsigned entity_attribute_id = entity_attribute->data().id();
 				IfcEntityList::ptr refs = entitiesByReference(entity_attribute_id);
 				if (!refs) {
 					refs = IfcEntityList::ptr(new IfcEntityList);
 					byref[entity_attribute_id] = refs;
 				}
-				refs->push(entity);
+				refs->push(instance);
 			}
 		} catch (const IfcParse::IfcException&) {}
 	}
 
-	return entity;
+	return instance;
 }
 
 IfcWrite::IfcWritableEntity* make_writable(IfcUtil::IfcBaseClass* instance) {
-	if (instance->entity->isWritable()) {
-		return instance->entity->isWritable();
+	if (instance->data().isWritable()) {
+		return instance->data().isWritable();
 	}
 
-	IfcWrite::IfcWritableEntity* return_value;
-	instance->entity = return_value = new IfcWrite::IfcWritableEntity(instance->entity);
+	IfcWrite::IfcWritableEntity* return_value = new IfcWrite::IfcWritableEntity(&instance->data());
+	instance->data(return_value);
 	return return_value;
 }
 
-void IfcFile::removeEntity(IfcUtil::IfcBaseClass* entity) {
-	const unsigned id = entity->entity->id();
-	IfcUtil::IfcBaseClass* file_entity = entityById(id);
+void IfcFile::removeEntity(IfcUtil::IfcBaseClass* instance) {
+	const unsigned id = instance->data().id();
+	IfcUtil::IfcBaseClass* file_instance = entityById(id);
 
 	// TODO: Create a set of weak relations. Inverse relations that do not dictate an 
 	// instance to be retained. For example: when deleting an IfcRepresentation, the 
@@ -1257,38 +1275,40 @@ void IfcFile::removeEntity(IfcUtil::IfcBaseClass* entity) {
 	// characterized as weak. 
 	std::set<IfcSchema::Type::Enum> weak_roots;
 
-	if (entity != file_entity) {
+	if (instance != file_instance) {
 		throw IfcParse::IfcException("Instance not part of this file");
 	}
 
 	std::set<IfcUtil::IfcBaseClass*> deletion_queue;
 	IfcEntityList::ptr references = entitiesByReference(id);
 
-	// Alter entity instances with INVERSE relations to the entity being 
+	// Alter entity instances with INVERSE relations to the instance being 
 	// deleted. This is necessary to maintain a valid IFC file, because 
 	// dangling references to it's entities name should be removed. At this
 	// moment, inversely related instances affected by the removal of the
-	// entity being deleted are not deleted themselves.
+	// instance being deleted are not deleted themselves.
 	if (references) {
 		for (IfcEntityList::it it = references->begin(); it != references->end(); ++it) {
 			IfcUtil::IfcBaseEntity* related_instance = (IfcUtil::IfcBaseEntity*) *it;
-			for (unsigned i = 0; i < related_instance->getArgumentCount(); ++i) {
-				Argument* attr = related_instance->getArgument(i);
+			for (unsigned i = 0; i < related_instance->data().getArgumentCount(); ++i) {
+				
+				Argument* attr = related_instance->data().getArgument(i);
 				if (attr->isNull()) continue;
 
-				IfcUtil::ArgumentType attr_type = related_instance->getArgumentType(i);
+				IfcUtil::ArgumentType attr_type = attr->type();
+
 				switch(attr_type) {
 				case IfcUtil::Argument_ENTITY_INSTANCE: {
 					IfcUtil::IfcBaseClass* instance_attribute = *attr;
-					if (instance_attribute == entity) {
+					if (instance_attribute == instance) {
 						make_writable(related_instance)->setArgument(i);
 						// deletion_queue.insert(related_instance);
 					} }
 					break;
 				case IfcUtil::Argument_AGGREGATE_OF_ENTITY_INSTANCE: {
 					IfcEntityList::ptr instance_list = *attr;
-					if (instance_list->contains(entity)) {
-						instance_list->remove(entity);
+					if (instance_list->contains(instance)) {
+						instance_list->remove(instance);
 						make_writable(related_instance)->setArgument(i, instance_list);
 						/* if (instance_list->size() == 0) {
 							deletion_queue.insert(related_instance);
@@ -1297,12 +1317,12 @@ void IfcFile::removeEntity(IfcUtil::IfcBaseClass* entity) {
 					break;
 				case IfcUtil::Argument_AGGREGATE_OF_AGGREGATE_OF_ENTITY_INSTANCE: {
 					IfcEntityListList::ptr instance_list_list = *attr;
-					if (instance_list_list->contains(entity)) {
+					if (instance_list_list->contains(instance)) {
 						IfcEntityListList::ptr new_list(new IfcEntityListList);
 						for (IfcEntityListList::outer_it it = instance_list_list->begin(); it != instance_list_list->end(); ++it) {
 							std::vector<IfcUtil::IfcBaseClass*> instances = *it;
 							std::vector<IfcUtil::IfcBaseClass*>::iterator jt;
-							while ((jt = std::find(instances.begin(), instances.end(), entity)) != instances.end()) {
+							while ((jt = std::find(instances.begin(), instances.end(), instance)) != instances.end()) {
 								instances.erase(jt);
 							}
 							new_list->push(instances);
@@ -1320,33 +1340,33 @@ void IfcFile::removeEntity(IfcUtil::IfcBaseClass* entity) {
 		byref.erase(byref.find(id));
 	}
 
-	IfcEntityList::ptr entity_attributes = traverse(entity, 1);
-	for (IfcEntityList::it it = entity_attributes->begin(); it != entity_attributes->end(); ++it) {
-		IfcUtil::IfcBaseClass* entity_attribute = *it;
-		if (entity_attribute == entity) continue;
-		entitiesByReference(entity_attribute->entity->id())->remove(entity);
-		if (entitiesByReference(entity_attribute->entity->id())->filtered(weak_roots)->size() == 0) {
-			deletion_queue.insert(entity_attribute);
+	IfcEntityList::ptr instance_attributes = traverse(instance, 1);
+	for (IfcEntityList::it it = instance_attributes->begin(); it != instance_attributes->end(); ++it) {
+		IfcUtil::IfcBaseClass* instance_attribute = *it;
+		if (instance_attribute == instance) continue;
+		entitiesByReference(instance_attribute->data().id())->remove(instance);
+		if (entitiesByReference(instance_attribute->data().id())->filtered(weak_roots)->size() == 0) {
+			deletion_queue.insert(instance_attribute);
 		}
 	}
 
-	if (entity->is(IfcSchema::Type::IfcRoot)) {
-		const std::string global_id = ((IfcSchema::IfcRoot*) entity)->GlobalId();
+	IfcSchema::IfcRoot* root = instance->as<IfcSchema::IfcRoot>();
+	if (root) {
+		const std::string global_id = root->GlobalId();
 		byguid.erase(byguid.find(global_id));
 	}
 	
 	byid.erase(byid.find(id));
 	
-	IfcEntityList::ptr instances_of_same_type = entitiesByType(entity->type());
-	instances_of_same_type->remove(entity);
+	IfcEntityList::ptr instances_of_same_type = entitiesByType(instance->declaration().type());
+	instances_of_same_type->remove(instance);
 
 	while (!deletion_queue.empty()) {
 		removeEntity(*deletion_queue.begin());
 		deletion_queue.erase(deletion_queue.begin());
 	}
 
-	delete entity->entity;
-	delete entity;
+	delete instance;
 }
 
 IfcEntityList::ptr IfcFile::entitiesByType(IfcSchema::Type::Enum t) {
@@ -1385,7 +1405,6 @@ IfcSchema::IfcRoot* IfcFile::entityByGuid(const std::string& guid) {
 // FIXME: Test destructor to delete entity and arg allocations
 IfcFile::~IfcFile() {
 	for( entity_by_id_t::const_iterator it = byid.begin(); it != byid.end(); ++ it ) {
-		delete it->second->entity;
 		delete it->second;
 	}
 	delete stream;
@@ -1405,8 +1424,8 @@ std::ostream& operator<< (std::ostream& os, const IfcParse::IfcFile& f) {
 
 	for ( IfcFile::entity_by_id_t::const_iterator it = f.begin(); it != f.end(); ++ it ) {
 		const IfcUtil::IfcBaseClass* e = it->second;
-		if (!IfcSchema::Type::IsSimple(e->type())) {
-			os << e->entity->toString(true) << ";" << std::endl;
+		if (!IfcSchema::Type::IsSimple(e->data().type())) {
+			os << e->data().toString(true) << ";" << std::endl;
 		}
 	}
 
@@ -1440,9 +1459,9 @@ IfcEntityList::ptr IfcFile::getInverse(int instance_id, IfcSchema::Type::Enum ty
 	if (!all) return l;
 
 	for(IfcEntityList::it it = all->begin(); it != all->end(); ++it) {
-		bool valid = type == IfcSchema::Type::UNDEFINED || (*it)->is(type);
+		bool valid = type == IfcSchema::Type::UNDEFINED || (*it)->declaration().is(type);
 		if (valid && attribute_index >= 0) {
-			Argument* arg = (*it)->entity->getArgument(attribute_index);
+			Argument* arg = (*it)->data().getArgument(attribute_index);
 			if (arg->type() == IfcUtil::Argument_ENTITY_INSTANCE) {
 				valid = instance == *arg;
 			} else if (arg->type() == IfcUtil::Argument_AGGREGATE_OF_ENTITY_INSTANCE) {
@@ -1490,21 +1509,21 @@ std::pair<IfcSchema::IfcNamedUnit*, double> IfcFile::getUnit(IfcSchema::IfcUnitE
 		IfcEntityList::ptr units = project->UnitsInContext()->Units();
 		for (IfcEntityList::it it = units->begin(); it != units->end(); ++it) {
 			IfcSchema::IfcUnit* unit = *it;
-			if (unit->is(IfcSchema::Type::IfcNamedUnit)) {
+			if (unit->declaration().is(IfcSchema::Type::IfcNamedUnit)) {
 				IfcSchema::IfcNamedUnit* named_unit = (IfcSchema::IfcNamedUnit*) unit;
 				if (named_unit->UnitType() != type) {
 					continue;
 				}
 				IfcSchema::IfcSIUnit* unit = 0;
-				if (named_unit->is(IfcSchema::Type::IfcConversionBasedUnit)) {
+				if (named_unit->declaration().is(IfcSchema::Type::IfcConversionBasedUnit)) {
 					IfcSchema::IfcConversionBasedUnit* u = (IfcSchema::IfcConversionBasedUnit*)named_unit;
 					IfcSchema::IfcMeasureWithUnit* mu = u->ConversionFactor();
-					return_value.second *= static_cast<double>(*mu->ValueComponent()->entity->getArgument(0));
+					return_value.second *= static_cast<double>(*mu->ValueComponent()->data().getArgument(0));
 					return_value.first = named_unit;
-					if (mu->UnitComponent()->is(IfcSchema::Type::IfcSIUnit)) {
+					if (mu->UnitComponent()->declaration().is(IfcSchema::Type::IfcSIUnit)) {
 						unit = (IfcSchema::IfcSIUnit*) mu->UnitComponent();
 					}
-				} else if (named_unit->is(IfcSchema::Type::IfcSIUnit)) {
+				} else if (named_unit->declaration().is(IfcSchema::Type::IfcSIUnit)) {
 					return_value.first = unit = (IfcSchema::IfcSIUnit*) named_unit;
 				}
 				if (unit) {

src/ifcparse/IfcParse.h

@@ -257,7 +257,8 @@ namespace IfcParse {
 		std::string datatype() const;
 		IfcSchema::Type::Enum type() const;
 		bool is(IfcSchema::Type::Enum v) const;
-		unsigned int id();
+		unsigned int id() const;
+		const IfcWrite::IfcWritableEntity* isWritable() const;
 		IfcWrite::IfcWritableEntity* isWritable();
 	};
 

src/ifcparse/IfcSchema.cpp

@@ -0,0 +1,21 @@
+#include "IfcSchema.h"
+
+bool IfcParse::declaration::is(const std::string& name) const {
+	return is(IfcSchema::Type::FromString(name));
+}
+
+bool IfcParse::declaration::is(IfcSchema::Type::Enum name) const {
+	if (this->as_entity()) {
+		return this->as_entity()->is(name);
+	} else {
+		return this->name() == IfcSchema::Type::ToString(name);
+	}
+}
+
+bool IfcParse::named_type::is(const std::string& name) const {
+	return declared_type()->is(name);
+}
+
+bool IfcParse::named_type::is(IfcSchema::Type::Enum name) const {
+	return declared_type()->is(name);
+}

src/ifcparse/IfcSchema.h

@@ -24,222 +24,295 @@
 #include <vector>
 #include <algorithm>
 
-class declaration; 
-class type_declaration; 
-class select_type; 
-class enumeration_type; 
-class entity;
+#ifdef USE_IFC4
+#include "../ifcparse/Ifc4enum.h"
+#else
+#include "../ifcparse/Ifc2x3enum.h"
+#endif
 
-class parameter_type {
-};
+namespace IfcParse {
 
-class named_type : public parameter_type {
-protected:
-	declaration* declared_type_;
-public:
-	named_type(declaration* declared_type)
-		: declared_type_(declared_type) {}
+	class declaration; 
+	
+	class type_declaration; 
+	class select_type; 
+	class enumeration_type; 
+	class entity;
 
-	declaration* declared_type() const { return declared_type_; }
-};
+	class named_type;
+	class simple_type;
+	class aggregation_type;
 
-class simple_type : public parameter_type {
-public:
-	typedef enum { binary_type, boolean_type, integer_type, logical_type, number_type, real_type, string_type } data_type;
-protected:
-	data_type declared_type_;
-public:
-	simple_type(data_type declared_type)
-		: declared_type_(declared_type) {}
+	class parameter_type {
+	public:
+		virtual const named_type* as_named_type() const { return static_cast<named_type*>(0); }
+		virtual const simple_type* as_simple_type() const { return static_cast<simple_type*>(0); }
+		virtual const aggregation_type* as_aggregation_type() const { return static_cast<aggregation_type*>(0); }
 
-	data_type declared_type() const { return declared_type_; }
-};
+		virtual bool is(const std::string& name) const { return false; }
+		virtual bool is(IfcSchema::Type::Enum name) const { return false; }
+	};
 
-class aggregation_type : public parameter_type {
-public:
-	typedef enum { array_type, bag_type, list_type, set_type } aggregate_type;
-protected:
-	aggregate_type type_of_aggregation_;
-	int bound1_, bound2_;
-	parameter_type* type_of_element_;
-public:
-	aggregation_type(aggregate_type type_of_aggregation, int bound1, int bound2, parameter_type* type_of_element)
-		: type_of_aggregation_(type_of_aggregation)
-		, bound1_(bound1)
-		, bound2_(bound2)
-		, type_of_element_(type_of_element)
-	{}
-
-	aggregate_type type_of_aggregation() const { type_of_aggregation_; }
-	int bound1() const { return bound1_; }
-	int bound2() const { return bound2_; }
-	parameter_type* type_of_element() const { return type_of_element_; }
-};
-
-class declaration {
-protected:
-	std::string name_;
-
-public:
-	declaration(const std::string& name)
-		: name_(name) {}
-
-	const std::string& name() const { return name_; }
-
-	virtual const type_declaration* as_type_declaration() const { return static_cast<type_declaration*>(0); }
-	virtual const select_type* as_select_type() const { return static_cast<select_type*>(0); }
-	virtual const enumeration_type* as_enumeration_type() const { return static_cast<enumeration_type*>(0); }
-	virtual const entity* as_entity() const { return static_cast<entity*>(0); }
-};
-
-class type_declaration : public declaration {
-protected:
-	const parameter_type* declared_type_;
-
-public:
-	type_declaration(const std::string& name, const parameter_type* declared_type)
-		: declaration(name)
-		, declared_type_(declared_type)	{}
-
-	const parameter_type* declared_type() const { return declared_type_; }
-
-	virtual const type_declaration* as_type_declaration() const { return this; }
-};
-
-class select_type : public declaration {
-protected:
-	std::vector<const declaration*> select_list_;
-public:
-	select_type(const std::string& name, const std::vector<const declaration*>& select_list)
-		: declaration(name)
-		, select_list_(select_list)	{}
-
-	const std::vector<const declaration*>& select_list() const { return select_list_; }
-
-	virtual const select_type* as_select_type() const { return this; }
-};
-
-class enumeration_type : public declaration {
-protected:
-	std::vector<std::string> enumeration_items_;
-public:
-	enumeration_type(const std::string& name, const std::vector<std::string>& enumeration_items)
-		: declaration(name)
-		, enumeration_items_(enumeration_items)	{}
-
-	const std::vector<std::string>& enumeration_items() const { return enumeration_items_; }
-
-	virtual const enumeration_type* as_enumeration_type() const { return this; }
-};
-
-class entity : public declaration {
-public:
-	class attribute {
+	class named_type : public parameter_type {
 	protected:
+		declaration* declared_type_;
+	public:
+		named_type(declaration* declared_type)
+			: declared_type_(declared_type) {}
+
+		declaration* declared_type() const { return declared_type_; }
+
+		virtual const named_type* as_named_type() const { return this; }
+
+		virtual bool is(const std::string& name) const;
+		virtual bool is(IfcSchema::Type::Enum name) const;
+	};
+
+	class simple_type : public parameter_type {
+	public:
+		typedef enum { binary_type, boolean_type, integer_type, logical_type, number_type, real_type, string_type } data_type;
+	protected:
+		data_type declared_type_;
+	public:
+		simple_type(data_type declared_type)
+			: declared_type_(declared_type) {}
+
+		data_type declared_type() const { return declared_type_; }
+
+		virtual const simple_type* as_simple_type() const { return this; }
+	};
+
+	class aggregation_type : public parameter_type {
+	public:
+		typedef enum { array_type, bag_type, list_type, set_type } aggregate_type;
+	protected:
+		aggregate_type type_of_aggregation_;
+		int bound1_, bound2_;
+		parameter_type* type_of_element_;
+	public:
+		aggregation_type(aggregate_type type_of_aggregation, int bound1, int bound2, parameter_type* type_of_element)
+			: type_of_aggregation_(type_of_aggregation)
+			, bound1_(bound1)
+			, bound2_(bound2)
+			, type_of_element_(type_of_element)
+		{}
+
+		aggregate_type type_of_aggregation() const { type_of_aggregation_; }
+		int bound1() const { return bound1_; }
+		int bound2() const { return bound2_; }
+		parameter_type* type_of_element() const { return type_of_element_; }
+
+		virtual const aggregation_type* as_aggregation_type() const { return this; }
+	};
+
+	class declaration {
+	protected:
+		// std::string name_;
+		IfcSchema::Type::Enum name_;
+
+	public:
+		declaration(IfcSchema::Type::Enum name)
+			: name_(name) {}
+		declaration(const std::string& name)
+			: name_(IfcSchema::Type::FromString(name)) {}
+
+		std::string name() const { return IfcSchema::Type::ToString(name_); }
+
+		virtual const type_declaration* as_type_declaration() const { return static_cast<type_declaration*>(0); }
+		virtual const select_type* as_select_type() const { return static_cast<select_type*>(0); }
+		virtual const enumeration_type* as_enumeration_type() const { return static_cast<enumeration_type*>(0); }
+		virtual const entity* as_entity() const { return static_cast<entity*>(0); }
+
+		// TODO: Type checking by Enum value
+		bool is(const std::string& name) const;
+		bool is(IfcSchema::Type::Enum name) const;
+
+		IfcSchema::Type::Enum type() const {
+			return name_;
+		}
+	};
+
+	class type_declaration : public declaration {
+	protected:
+		const parameter_type* declared_type_;
+
+	public:
+		type_declaration(const std::string& name, const parameter_type* declared_type)
+			: declaration(name)
+			, declared_type_(declared_type)	{}
+		type_declaration(IfcSchema::Type::Enum name, const parameter_type* declared_type)
+			: declaration(name)
+			, declared_type_(declared_type)	{}
+
+		const parameter_type* declared_type() const { return declared_type_; }
+
+		virtual const type_declaration* as_type_declaration() const { return this; }
+	};
+
+	class select_type : public declaration {
+	protected:
+		std::vector<const declaration*> select_list_;
+	public:
+		select_type(const std::string& name, const std::vector<const declaration*>& select_list)
+			: declaration(name)
+			, select_list_(select_list)	{}
+		select_type(IfcSchema::Type::Enum name, const std::vector<const declaration*>& select_list)
+			: declaration(name)
+			, select_list_(select_list)	{}
+
+		const std::vector<const declaration*>& select_list() const { return select_list_; }
+
+		virtual const select_type* as_select_type() const { return this; }
+	};
+
+	class enumeration_type : public declaration {
+	protected:
+		std::vector<std::string> enumeration_items_;
+	public:
+		enumeration_type(const std::string& name, const std::vector<std::string>& enumeration_items)
+			: declaration(name)
+			, enumeration_items_(enumeration_items)	{}
+		enumeration_type(IfcSchema::Type::Enum name, const std::vector<std::string>& enumeration_items)
+			: declaration(name)
+			, enumeration_items_(enumeration_items)	{}
+
+		const std::vector<std::string>& enumeration_items() const { return enumeration_items_; }
+
+		virtual const enumeration_type* as_enumeration_type() const { return this; }
+	};
+
+	class entity : public declaration {
+	public:
+		class attribute {
+		protected:
+			std::string name_;
+			const parameter_type* type_of_attribute_;
+			bool optional_;
+
+		public:
+			attribute(const std::string& name, parameter_type* type_of_attribute, bool optional)
+				: name_(name)
+				, type_of_attribute_(type_of_attribute)
+				, optional_(optional) {}
+
+			const std::string& name() const { return name_; }
+			const parameter_type* type_of_attribute() const { return type_of_attribute_; }
+			bool optional() const { return optional_; }
+		};
+
+	protected:
+		const entity* supertype_; /* NB: IFC explicitly allows only single inheritance */
+		std::vector<const entity*> subtypes_;
+
+		std::vector<const attribute*> attributes_;
+		std::vector<bool> derived_;
+	
+	public:
+		entity(const std::string& name, entity* supertype)
+			: declaration(name)
+			, supertype_(supertype)
+		{}
+		entity(IfcSchema::Type::Enum name, entity* supertype)
+			: declaration(name)
+			, supertype_(supertype)
+		{}
+
+		bool is(const std::string& name) const {
+			return is(IfcSchema::Type::FromString(name));
+		}
+
+		bool is(IfcSchema::Type::Enum name) const {
+			if (name == name_) return true;
+			else if (supertype_) return supertype_->is(name);
+			else return false;
+		}
+
+		void set_subtypes(const std::vector<const entity*>& subtypes) {
+			subtypes_ = subtypes;
+		}
+
+		void set_attributes(const std::vector<const attribute*>& attributes, const std::vector<bool>& derived) {
+			attributes_ = attributes;
+			derived_ = derived;
+		}
+
+		const std::vector<const entity*>& subtypes() const { return subtypes_; }
+		const std::vector<const attribute*>& attributes() const { return attributes_; }
+		const std::vector<bool>& derived() const { return derived_; }
+	
+		const std::vector<const attribute*> all_attributes() const {
+			std::vector<const attribute*> attrs;
+			attrs.reserve(derived_.size());
+			std::vector<const attribute*>::iterator it = attrs.begin();
+			if (supertype_) {
+				const std::vector<const attribute*> supertype_attrs = supertype_->all_attributes();
+				it = std::copy(supertype_attrs.begin(), supertype_attrs.end(), it);
+			}
+			std::copy(attributes_.begin(), attributes_.end(), it);
+			return attrs;
+		}
+
+		virtual const entity* as_entity() const { return this; }
+	};
+
+	class schema_definition {
+	private:
+		bool built_in_;
+
 		std::string name_;
-		const parameter_type* type_of_attribute_;
-		bool optional_;
+
+		std::vector<const declaration*> declarations_;
+
+		std::vector<const type_declaration*> type_declarations_;
+		std::vector<const select_type*> select_types_;
+		std::vector<const enumeration_type*> enumeration_types_;
+
+		class declaration_by_name_cmp : public std::binary_function<const declaration*, const std::string&, bool> {
+		public:
+			bool operator()(const declaration* decl, const std::string& name) {
+				return decl->name() < name;
+			}
+		};
 
 	public:
-		attribute(const std::string& name, parameter_type* type_of_attribute, bool optional)
+		schema_definition(const std::string& name, const std::vector<const declaration*>& declarations, const bool built_in = false)
 			: name_(name)
-			, type_of_attribute_(type_of_attribute)
-			, optional_(optional) {}
+			, declarations_(declarations)
+			, built_in_(built_in)
+		{
+			for (std::vector<const declaration*>::const_iterator it = declarations_.begin(); it != declarations_.end(); ++it) {
+				if ((**it).as_type_declaration()) type_declarations_.push_back((**it).as_type_declaration());
+				if ((**it).as_select_type()) select_types_.push_back((**it).as_select_type());
+				if ((**it).as_enumeration_type()) enumeration_types_.push_back((**it).as_enumeration_type());
+			}
+		}
 
-		const std::string& name() const { return name_; }
-		const parameter_type* type_of_attribute() const { return type_of_attribute_; }
-		bool optional() const { return optional_; }
+		~schema_definition() {
+			for (std::vector<const declaration*>::const_iterator it = declarations_.begin(); it != declarations_.end(); ++it) {
+				delete *it;
+			}
+		}
+
+		const declaration* declaration_by_name(const std::string& name) const {
+			std::vector<const declaration*>::const_iterator it = std::lower_bound(declarations_.begin(), declarations_.end(), name, declaration_by_name_cmp());
+			if (it == declarations_.end() || (**it).name() != name) {
+				throw;
+			} else {
+				return *it;
+			}
+		}
+
+		const declaration* declaration_by_name(IfcSchema::Type::Enum name) const {
+			if (!built_in_) throw;
+			return declaration_by_name(IfcSchema::Type::ToString(name));
+		}
+
+		const std::vector<const declaration*>& declarations() { return declarations_; }
+		const std::vector<const type_declaration*>& type_declarations() { return type_declarations_; }
+		const std::vector<const select_type*>& select_types() { return select_types_; }
+		const std::vector<const enumeration_type*>& enumeration_types() { return enumeration_types_; }
 	};
 
-protected:
-	const entity* supertype_; /* NB: IFC explicitly allows only single inheritance */
-	std::vector<const entity*> subtypes_;
+}
 
-	std::vector<const attribute*> attributes_;
-	std::vector<bool> derived_;
-	
-public:
-	entity(const std::string& name, entity* supertype)
-		: declaration(name)
-		, supertype_(supertype)
-	{}
-
-	void set_subtypes(const std::vector<const entity*>& subtypes) {
-		subtypes_ = subtypes;
-	}
-
-	void set_attributes(const std::vector<const attribute*>& attributes, const std::vector<bool>& derived) {
-		attributes_ = attributes;
-		derived_ = derived;
-	}
-
-	const std::vector<const entity*>& subtypes() const { return subtypes_; }
-	const std::vector<const attribute*>& attributes() const { return attributes_; }
-	const std::vector<bool>& derived() const { return derived_; }
-	
-	const std::vector<const attribute*> all_attributes() const {
-		std::vector<const attribute*> attrs;
-		attrs.reserve(derived_.size());
-		std::vector<const attribute*>::iterator it = attrs.begin();
-		if (supertype_) {
-			const std::vector<const attribute*> supertype_attrs = supertype_->all_attributes();
-			it = std::copy(supertype_attrs.begin(), supertype_attrs.end(), it);
-		}
-		std::copy(attributes_.begin(), attributes_.end(), it);
-		return attrs;
-	}
-
-	virtual const entity* as_entity() const { return this; }
-};
-
-class schema_definition {
-private:
-	std::string name_;
-
-	std::vector<const declaration*> declarations_;
-
-	std::vector<const type_declaration*> type_declarations_;
-	std::vector<const select_type*> select_types_;
-	std::vector<const enumeration_type*> enumeration_types_;
-
-	class declaration_by_name_cmp : public std::binary_function<const declaration*, const std::string&, bool> {
-	public:
-		bool operator()(const declaration* decl, const std::string& name) {
-			return decl->name() < name;
-		}
-	};
-
-public:
-	schema_definition(const std::string& name, const std::vector<const declaration*>& declarations)
-		: name_(name)
-		, declarations_(declarations)
-	{
-		for (std::vector<const declaration*>::const_iterator it = declarations_.begin(); it != declarations_.end(); ++it) {
-			if ((**it).as_type_declaration()) type_declarations_.push_back((**it).as_type_declaration());
-			if ((**it).as_select_type()) select_types_.push_back((**it).as_select_type());
-			if ((**it).as_enumeration_type()) enumeration_types_.push_back((**it).as_enumeration_type());
-		}
-	}
-
-	~schema_definition() {
-		for (std::vector<const declaration*>::const_iterator it = declarations_.begin(); it != declarations_.end(); ++it) {
-			delete *it;
-		}
-	}
-
-	const declaration* declaration_by_name(const std::string& name) {
-		std::vector<const declaration*>::const_iterator it = std::lower_bound(declarations_.begin(), declarations_.end(), name, declaration_by_name_cmp());
-		if (it == declarations_.end() || (**it).name() != name) {
-			throw;
-		} else {
-			return *it;
-		}
-	}
-
-	const std::vector<const declaration*>& declarations() { return declarations_; }
-	const std::vector<const type_declaration*>& type_declarations() { return type_declarations_; }
-	const std::vector<const select_type*>& select_types() { return select_types_; }
-	const std::vector<const enumeration_type*>& enumeration_types() { return enumeration_types_; }
-};
-
-#endif
+#endif

src/ifcparse/IfcSpfHeader.h

@@ -91,7 +91,11 @@ public:
 		return ss.str();
 	}
 	
-	unsigned int id() {
+	unsigned int id() const {
+		return 0;
+	}
+
+	const IfcWrite::IfcWritableEntity* isWritable() const {
 		return 0;
 	}
 

src/ifcparse/IfcUtil.cpp

@@ -56,7 +56,7 @@ IfcEntityList::ptr IfcEntityList::filtered(const std::set<IfcSchema::Type::Enum>
 	for (it it = begin(); it != end(); ++it) {
 		bool contained = false;
 		for (std::set<IfcSchema::Type::Enum>::const_iterator jt = entities.begin(); jt != entities.end(); ++jt) {
-			if ((*it)->is(*jt)) {
+			if ((*it)->declaration().is(*jt)) {
 				contained = true;
 				break;
 			}
@@ -69,9 +69,9 @@ IfcEntityList::ptr IfcEntityList::filtered(const std::set<IfcSchema::Type::Enum>
 }
 
 
-unsigned int IfcUtil::IfcBaseType::getArgumentCount() const { return 1; }
-Argument* IfcUtil::IfcBaseType::getArgument(unsigned int i) const { return entity->getArgument(i); }
-const char* IfcUtil::IfcBaseType::getArgumentName(unsigned int i) const { if (i == 0) { return "wrappedValue"; } else { throw IfcParse::IfcAttributeOutOfRangeException("Argument index out of range"); } }
+// unsigned int IfcUtil::IfcBaseType::getArgumentCount() const { return 1; }
+// Argument* IfcUtil::IfcBaseType::getArgument(unsigned int i) const { return entity->getArgument(i); }
+// const char* IfcUtil::IfcBaseType::getArgumentName(unsigned int i) const { if (i == 0) { return "wrappedValue"; } else { throw IfcParse::IfcAttributeOutOfRangeException("Argument index out of range"); } }
 
 void Logger::SetOutput(std::ostream* l1, std::ostream* l2) { 
 	log1 = l1; 
@@ -80,10 +80,10 @@ void Logger::SetOutput(std::ostream* l1, std::ostream* l2) {
 		log2 = &log_stream;
 	}
 }
-void Logger::Message(Logger::Severity type, const std::string& message, IfcAbstractEntity* entity) {
+void Logger::Message(Logger::Severity type, const std::string& message, const IfcUtil::IfcBaseClass* entity) {
 	if ( log2 && type >= verbosity ) {
 		(*log2) << "[" << severity_strings[type] << "] " << message << std::endl;
-		if ( entity ) (*log2) << entity->toString() << std::endl;
+		if ( entity ) (*log2) << entity->data().toString() << std::endl;
 	}
 }
 void Logger::Status(const std::string& message, bool new_line) {
@@ -143,4 +143,13 @@ bool IfcUtil::valid_binary_string(const std::string& s) {
 		if (*it != '0' && *it != '1') return false;
 	}
 	return true;
+}
+
+IfcUtil::IfcBaseClass::~IfcBaseClass() {
+	delete data_; 
+}
+
+void IfcUtil::IfcBaseClass::data(IfcAbstractEntity* d) {
+	delete data_;
+	data_ = d; 
 }

src/ifcparse/IfcUtil.h

@@ -28,6 +28,7 @@
 
 #include <boost/dynamic_bitset.hpp>
 
+#include "../ifcparse/IfcSchema.h"
 #include "../ifcparse/SharedPointer.h"
 
 #ifdef USE_IFC4
@@ -40,6 +41,13 @@ class Argument;
 class IfcEntityList;
 class IfcEntityListList;
 class IfcAbstractEntity;
+
+namespace IfcParse { // these have to be declared first in order for the virtual function below to be covariant. separate into different header file
+	class declaration;
+	class entity;
+	class type_declaration;
+}
+
 namespace IfcWrite {
 	class IfcWritableEntity;
 }
@@ -72,35 +80,53 @@ namespace IfcUtil {
 	const char* ArgumentTypeToString(ArgumentType argument_type);
 
 	class IfcBaseClass {
+	protected:
+		IfcAbstractEntity* data_;
 	public:
-		IfcAbstractEntity* entity;
-		virtual bool is(IfcSchema::Type::Enum v) const = 0;
-		virtual IfcSchema::Type::Enum type() const = 0;
+		IfcBaseClass() : data_(0) {}
+		IfcBaseClass(IfcAbstractEntity* d) : data_(d) {}
+		virtual ~IfcBaseClass();
 
-		virtual unsigned int getArgumentCount() const = 0;
-		virtual ArgumentType getArgumentType(unsigned int i) const = 0;
-		virtual IfcSchema::Type::Enum getArgumentEntity(unsigned int i) const = 0;
-		virtual Argument* getArgument(unsigned int i) const = 0;
-		virtual const char* getArgumentName(unsigned int i) const = 0;
+		const IfcAbstractEntity& data() const { return *data_; }
+		IfcAbstractEntity& data() { return *data_; }
+
+		void data(IfcAbstractEntity* d);
+
+		virtual const IfcParse::declaration& declaration() const = 0;
 
 		template <class T>
 		T* as() {
-			return is(T::Class()) 
+			return declaration().is(T::Class()) 
 				? static_cast<T*>(this) 
 				: static_cast<T*>(0);
 		}
+
+		template <class T>
+		const T* as() const {
+			return declaration().is(T::Class()) 
+				? static_cast<const T*>(this) 
+				: static_cast<const T*>(0);
+		}
+	private:
+		IfcBaseClass(const IfcBaseClass&);
+		IfcBaseClass& operator=(const IfcBaseClass&);
 	};
 
 	class IfcBaseEntity : public IfcBaseClass {
+	public:
+		IfcBaseEntity() : IfcBaseClass() {}
+		IfcBaseEntity(IfcAbstractEntity* d) : IfcBaseClass(d) {}
+
+		virtual const IfcParse::entity& declaration() const = 0;
 	};
 
 	// TODO: Investigate whether these should be template classes instead
-	class IfcBaseType : public IfcBaseEntity {
+	class IfcBaseType : public IfcBaseClass {
 	public:
-		unsigned int getArgumentCount() const;
-		Argument* getArgument(unsigned int i) const;
-		const char* getArgumentName(unsigned int i) const;
-		IfcSchema::Type::Enum getArgumentEntity(unsigned int i) const { return IfcSchema::Type::UNDEFINED; }
+		IfcBaseType() : IfcBaseClass() {}
+		IfcBaseType(IfcAbstractEntity* d) : IfcBaseClass(d) {}
+
+		virtual const IfcParse::type_declaration& declaration() const = 0;
 	};
 
 	bool valid_binary_string(const std::string& s);
@@ -125,7 +151,7 @@ public:
 	typename U::list::ptr as() {
 		typename U::list::ptr r(new typename U::list);
 		const bool all = U::Class() == IfcSchema::Type::UNDEFINED;
-		for ( it i = begin(); i != end(); ++ i ) if (all || (*i)->is(U::Class())) r->push((U*)*i);
+		for ( it i = begin(); i != end(); ++ i ) if (all || (*i)->declaration().is(U::Class())) r->push((U*)*i);
 		return r;
 	}
 	void remove(IfcUtil::IfcBaseClass*);
@@ -153,7 +179,7 @@ public:
 	typename U::list::ptr as() {
 		typename U::list::ptr r(new typename U::list);
 		const bool all = U::Class() == IfcSchema::Type::UNDEFINED;
-		for ( it i = begin(); i != end(); ++ i ) if (all || (*i)->is(U::Class())) r->push((U*)*i);
+		for ( it i = begin(); i != end(); ++ i ) if (all || (*i)->declaration().is(U::Class())) r->push((U*)*i);
 		return r;
 	}
 	void remove(T* t) {
@@ -305,7 +331,8 @@ public:
 	virtual IfcSchema::Type::Enum type() const = 0;
 	virtual bool is(IfcSchema::Type::Enum v) const = 0;
 	virtual std::string toString(bool upper=false) const = 0;
-	virtual unsigned int id() = 0;
+	virtual unsigned int id() const = 0;
+	virtual const IfcWrite::IfcWritableEntity* isWritable() const = 0;
 	virtual IfcWrite::IfcWritableEntity* isWritable() = 0;
 };
 
@@ -325,7 +352,7 @@ public:
 	static void Verbosity(Severity v);
 	static Severity Verbosity();
 	/// Log a message to the output stream
-	static void Message(Severity type, const std::string& message, IfcAbstractEntity* entity=0);
+	static void Message(Severity type, const std::string& message, const IfcUtil::IfcBaseClass* instance=0);
 	static void Status(const std::string& message, bool new_line=true);
 	static void ProgressBar(int progress);
 	static std::string GetLog();

src/ifcparse/IfcWritableEntity.h

@@ -40,12 +40,17 @@
 namespace IfcWrite {
 	class IfcWritableEntity : public IfcAbstractEntity {
 	private:
+		// Mutable because calling id() will generate a fresh id on
+		// the current file, in case none has been assigned previously
+		mutable int* _id;
+		
 		std::map<int,bool> writemask;
 		std::map<int,Argument*> args;
 		IfcSchema::Type::Enum _type;
-		int* _id;
+
 		bool arg_writable(int i);
 		void arg_writable(int i, bool b);
+		
 		template <typename T> void _setArgument(int i, const T&);
 	public:
 		IfcWritableEntity(IfcSchema::Type::Enum t);
@@ -60,7 +65,8 @@ namespace IfcWrite {
 		IfcSchema::Type::Enum type() const;
 		bool is(IfcSchema::Type::Enum v) const;
 		std::string toString(bool upper=false) const;
-		unsigned int id();
+		unsigned int id() const;
+		const IfcWritableEntity* isWritable() const;
 		IfcWritableEntity* isWritable();
 
 		void setArgument(int i, Argument* a);

src/ifcparse/IfcWrite.cpp

@@ -109,12 +109,13 @@ std::string IfcWritableEntity::toString(bool upper) const {
 
 	return ss.str();
 }
-unsigned int IfcWritableEntity::id() { 
+unsigned int IfcWritableEntity::id() const { 
 	if ( !_id ) {
 		_id = new int(file->FreshId()); 
 	}
 	return *_id; 
 }
+const IfcWritableEntity* IfcWritableEntity::isWritable() const { return this; }
 IfcWritableEntity* IfcWritableEntity::isWritable() { return this; }
 bool IfcWritableEntity::arg_writable(int i) {
 	std::map<int,bool>::const_iterator it = writemask.find(i);
@@ -390,11 +391,11 @@ public:
 		data << "." << i.enumeration_value << ".";
 	}
 	void operator()(const IfcUtil::IfcBaseClass* const& i) { 
-		IfcAbstractEntity* e = i->entity;
-		if ( IfcSchema::Type::IsSimple(e->type()) ) {
-			data << e->toString(upper);
+		const IfcAbstractEntity& e = i->data();
+		if ( IfcSchema::Type::IsSimple(e.type()) ) {
+			data << e.toString(upper);
 		} else {
-			data << "#" << e->id();
+			data << "#" << e.id();
 		}
 	}
 	void operator()(const IfcEntityList::ptr& i) {