IfcOpenShell/src/ifcparse/IfcBaseClass.h

/********************************************************************************
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 * This file is part of IfcOpenShell.                                           *
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 * IfcOpenShell is free software: you can redistribute it and/or modify         *
 * it under the terms of the Lesser GNU General Public License as published by  *
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 * (at your option) any later version.                                          *
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of               *
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the                 *
 * Lesser GNU General Public License for more details.                          *
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 * You should have received a copy of the Lesser GNU General Public License     *
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#ifndef IFCBASECLASS_H
#define IFCBASECLASS_H

#include "ifc_parse_api.h"

#include "../ifcparse/IfcEntityInstanceData.h"
#include "../ifcparse/IfcSchema.h"
#include "../ifcparse/utils.h"

#include <boost/shared_ptr.hpp>

#include <atomic>

class Argument;
class aggregate_of_instance;

namespace IfcUtil {

	class IFC_PARSE_API IfcBaseInterface {
	protected:
		static bool is_null(const IfcBaseInterface* not_this) {
			return !not_this;
		}

		template<typename T>
		std::enable_if_t<!std::is_same<IfcBaseClass, T>::value && !std::is_same<IfcBaseEntity, T>::value && !std::is_same<IfcBaseType, T>::value> raise_error_on_concrete_class() const {
			throw IfcParse::IfcException("Instance of type " + this->declaration().name() + " cannot be cast to " + T::Class().name());
		}

		template<typename T>
		std::enable_if_t<std::is_same<IfcBaseClass, T>::value || std::is_same<IfcBaseEntity, T>::value || std::is_same<IfcBaseType, T>::value> raise_error_on_concrete_class() const {
			throw IfcParse::IfcException("Instance of type " + this->declaration().name() + " cannot be cast to base class");
		}

	public:
		virtual const IfcEntityInstanceData& data() const = 0;
		virtual IfcEntityInstanceData& data() = 0;
		virtual const IfcParse::declaration& declaration() const = 0;

		template <class T>
		T* as(bool do_throw = false) {
			// @todo: do not allow this to be null in the first place
			if (is_null(this)) {
				return static_cast<T*>(0);
			}
			auto t = dynamic_cast<T*>(this);
			if (do_throw && !t) {
				raise_error_on_concrete_class<T>();
			}
			return t;
		}

		template <class T>
		const T* as(bool do_throw = false) const {
			if (is_null(this)) {
				return static_cast<const T*>(0);
			}
			auto t = dynamic_cast<const T*>(this);
			if (do_throw && !t) {
				raise_error_on_concrete_class<T>();
			}
			return t;
		}
	};

	class IFC_PARSE_API IfcBaseClass : public virtual IfcBaseInterface {
	private:
		uint32_t identity_;
		static std::atomic_uint32_t counter_;

	protected:
		IfcEntityInstanceData* data_;

		static bool is_null(const IfcBaseClass* not_this) {
			return !not_this;
		}        
	public:
        IfcBaseClass() : identity_(counter_++), data_(0) {}
		IfcBaseClass(IfcEntityInstanceData* d) : identity_(counter_++), data_(d) {}
		virtual ~IfcBaseClass() { delete data_; }
        
        const IfcEntityInstanceData& data() const { return *data_; }
		IfcEntityInstanceData& data() { return *data_; }
        void data(IfcEntityInstanceData* d);
        
        virtual const IfcParse::declaration& declaration() const = 0;

		uint32_t identity() const { return identity_; }
	};

	class IFC_PARSE_API IfcLateBoundEntity : public IfcBaseClass {
	private:
		const IfcParse::declaration* decl_;

	public:
		IfcLateBoundEntity(const IfcParse::declaration* decl, IfcEntityInstanceData* data) : IfcBaseClass(data), decl_(decl) {}

		virtual const IfcParse::declaration& declaration() const {
			return *decl_;
		}
	};

	class IFC_PARSE_API IfcBaseEntity : public IfcBaseClass {
	public:
		IfcBaseEntity() : IfcBaseClass() {}
		IfcBaseEntity(IfcEntityInstanceData* d) : IfcBaseClass(d) {}

		virtual const IfcParse::entity& declaration() const = 0;

		Argument* get(const std::string& name) const;

		boost::shared_ptr<aggregate_of_instance> get_inverse(const std::string& a) const;
	};

	// TODO: Investigate whether these should be template classes instead
	class IFC_PARSE_API IfcBaseType : public IfcBaseClass {
	public:
		IfcBaseType() : IfcBaseClass() {}
		IfcBaseType(IfcEntityInstanceData* d) : IfcBaseClass(d) {}

		virtual const IfcParse::declaration& declaration() const = 0;
	};

}

#endif