#ifndef CONVERSIONSETTINGS_H
#define CONVERSIONSETTINGS_H

#include <array>
#include <limits>
#include <string>
#include <iostream>
#include <string>
#include <map>
#include <tuple>
#include <type_traits>

#include <boost/program_options.hpp>
#include <boost/optional.hpp>
#include <boost/variant.hpp>
#include <boost/algorithm/string.hpp>
#include <boost/optional/optional_io.hpp>

#include "ifc_geom_api.h"

#ifndef SWIG
namespace po = boost::program_options;

namespace std {
	IFC_GEOM_API istream& operator>>(istream& in, set<int>& ints);
	IFC_GEOM_API istream& operator>>(istream& in, set<string>& ints);
	IFC_GEOM_API istream& operator>>(istream& in, vector<double>& vs);
}
#endif

namespace ifcopenshell {
	namespace geometry {
		inline namespace settings {

#ifndef SWIG
			template <typename T, typename U = int>
			struct HasDefault : std::false_type { };

			template <typename T>
			struct HasDefault<T, decltype((void)T::defaultvalue, 0)> : std::true_type { };
#endif

			template <typename Derived, typename T, bool Internal=false>
			struct SettingBase {
				typedef T base_type;

				// boost program options does not seem to handle optional<vector> types, so in case
				// of vector settings we need to strip away the optional and detect argument presence
				// with !vector::empty()
				// tfk: we no longer do this because negative values can not be passed like this as boost confuses them with options
				// std::conditional_t<std::is_same_v<T, std::vector<double>>, T, boost::optional<T>> value;
				boost::optional<T> value;

				SettingBase() {}

				void defineOption(po::options_description& desc) {
					auto apply_default = [](auto x) {
						if constexpr (HasDefault<Derived>()) {
							return x->default_value(Derived::defaultvalue);
						} else {
							return x;
						}
					};
					if constexpr (Internal) {
						// do nothing, this is an internal setting and not supposed to be set from the command line
					} else if constexpr (std::is_same_v<T, bool>) {
						// @todo bool_switch doesn't work with optional unfortunately...
						value.emplace();
						desc.add_options()(Derived::name, apply_default(po::bool_switch(&*value)), Derived::description);
					} else if constexpr (std::is_same_v<T, std::vector<double>>) {
						// these options have to be supplied manually in IfcConvert.cpp
						// desc.add_options()(Derived::name, apply_default(po::value(&value)->multitoken()), Derived::description);
					} else {
						desc.add_options()(Derived::name, apply_default(po::value(&value)), Derived::description);
					}
				}

				T get() const {
					if constexpr (false && std::is_same_v<T, std::vector<double>>) {
						return value;
					} else {
						if (value) {
							return value.get();
						}
						if constexpr (HasDefault<Derived>()) {
							return Derived::defaultvalue;
						} else {
						    throw std::runtime_error("Setting not set");
						}
					}
				}

				bool has() const {
					if constexpr (false && std::is_same_v<T, std::vector<double>>) {
						return !value.empty();
					} else {
						// @todo this is not reliable, better use vmap[...].defaulted()
						return !!value;
					}
				}
			};

			// These are the old geometry settings values from the kernel

			struct MesherLinearDeflection : public SettingBase<MesherLinearDeflection, double> {
				static constexpr const char* const name = "mesher-linear-deflection";
				static constexpr const char* const description = "Specifies the linear deflection of the mesher. Controls the detail of curved surfaces in triangulated output formats.";
				static constexpr double defaultvalue = 0.001;
			};

			struct MesherAngularDeflection : public SettingBase<MesherAngularDeflection, double> {
				static constexpr const char* const name = "mesher-angular-deflection";
				static constexpr const char* const description = "Sets the angular tolerance of the mesher in radians 0.5 by default if not specified.";
				static constexpr double defaultvalue = 0.5;
			};

			struct ReorientShells : public SettingBase<ReorientShells, bool> {
				static constexpr const char* const name = "reorient-shells";
				static constexpr const char* const description = "Specifies whether to orient the faces of IfcConnectedFaceSets. "
					"This is a potentially time consuming operation, but guarantees a "
					"consistent orientation of surface normals, even if the faces are not "
					"properly oriented in the IFC file.";
				static constexpr bool defaultvalue = false;
			};

			struct LengthUnit : public SettingBase<LengthUnit, double, true> {
				static constexpr const char* const name = "length-unit";
				static constexpr const char* const description = "";
				static constexpr double defaultvalue = 1.0;
			};

			struct PlaneUnit : public SettingBase<PlaneUnit, double, true> {
				static constexpr const char* const name = "angle-unit";
				static constexpr const char* const description = "";
				static constexpr double defaultvalue = 1.0;
			};

			struct Precision : public SettingBase<Precision, double, true> {
				static constexpr const char* const name = "precision";
				static constexpr const char* const description = "";
				static constexpr double defaultvalue = 0.00001;
			};

			struct LayersetFirst : public SettingBase<LayersetFirst, bool> {
				static constexpr const char* const name = "layerset-first";
				static constexpr const char* const description = "Assigns the first layer material of the layerset "
					"to the complete product.";
				static constexpr bool defaultvalue = false;
			};

			struct DisableBooleanResult : public SettingBase<DisableBooleanResult, bool> {
				static constexpr const char* const name = "disable-boolean-result";
				static constexpr const char* const description = "Specifies whether to disable the boolean operation within representations "
			"such as clippings by means of IfcBooleanResult and subtypes";
				static constexpr bool defaultvalue = false;
			};

			struct NoWireIntersectionCheck : public SettingBase<NoWireIntersectionCheck, bool> {
				static constexpr const char* const name = "no-wire-intersection-check";
				static constexpr const char* const description = "Skip wire intersection check.";
				static constexpr bool defaultvalue = false;
			};

			struct NoWireIntersectionTolerance : public SettingBase<NoWireIntersectionTolerance, double> {
				static constexpr const char* const name = "no-wire-intersection-tolerance";
				static constexpr const char* const description = "Set wire intersection tolerance to 0.";
				static constexpr bool defaultvalue = false;
			};

			struct PrecisionFactor : public SettingBase<PrecisionFactor, double> {
				static constexpr const char* const name = "precision-factor";
				static constexpr const char* const description = "Option to increase linear tolerance for more permissive edge curves and fewer artifacts after "
					"boolean operations at the expense of geometric detail "
					"due to vertex collapsing and wire intersection fuzziness.";
				static constexpr double defaultvalue = 1.0;
			};

			struct DebugBooleanOperations : public SettingBase<DebugBooleanOperations, bool> {
				static constexpr const char* const name = "debug";
				static constexpr const char* const description = "write boolean operands to file in current directory for debugging purposes";
				static constexpr bool defaultvalue = false;
			};

			struct BooleanAttempt2d : public SettingBase<BooleanAttempt2d, bool> {
				static constexpr const char* const name = "boolean-attempt-2d";
				static constexpr const char* const description = "Do not attempt to process boolean subtractions in 2D.";
				static constexpr bool defaultvalue = true;
			};

			// These are the old IteratorSettings

			struct WeldVertices : public SettingBase<WeldVertices, bool> {
				static constexpr const char* const name = "weld-vertices";
				static constexpr const char* const description = "Specifies whether vertices are welded, meaning that the coordinates "
					"vector will only contain unique xyz-triplets. This results in a "
					"manifold mesh which is useful for modelling applications, but might "
					"result in unwanted shading artefacts in rendering applications.";
				static constexpr bool defaultvalue = true;
			};

			struct UseWorldCoords : public SettingBase<UseWorldCoords, bool> {
				static constexpr const char* const name = "use-world-coords";
				static constexpr const char* const description = "Specifies whether to apply the local placements of building elements "
					"directly to the coordinates of the representation mesh rather than "
					"to represent the local placement in the 4x3 matrix, which will in that "
					"case be the identity matrix.";
				static constexpr bool defaultvalue = false;
			};

			struct UnifyShapes : public SettingBase<UnifyShapes, bool> {
				static constexpr const char* const name = "unify-shapes";
				static constexpr const char* const description = "Unify adjacent co-planar and co-linear subshapes (topological entities "
					"sharing the same geometric domain) before triangulation or further processing";
				static constexpr bool defaultvalue = false;
			};

			struct UseMaterialNames : public SettingBase<UseMaterialNames, bool> {
				static constexpr const char* const name = "use-material-names";
				static constexpr const char* const description = "Use material names instead of unique IDs for naming materials upon serialization. "
					"Applicable for OBJ and DAE output.";
				static constexpr bool defaultvalue = false;
			};

			struct ConvertBackUnits : public SettingBase<ConvertBackUnits, bool> {
				static constexpr const char* const name = "convert-back-units";
				static constexpr const char* const description = "Specifies whether to convert back geometrical output back to the "
					"unit of measure in which it is defined in the IFC file. Default is "
					"to use meters.";
				static constexpr bool defaultvalue = false;
			};

			struct ContextIds : public SettingBase<ContextIds, std::set<int>> {
				static constexpr const char* const name = "context-ids";
				static constexpr const char* const description = "List of comma separated context ids to process - e.g. '15,29' (no quotes needed).";
			};

			struct ContextTypes : public SettingBase<ContextTypes, std::set<std::string>> {
				static constexpr const char* const name = "context-types";
				static constexpr const char* const description = "Currently option has no effect.";
			};

			struct ContextIdentifiers : public SettingBase<ContextIdentifiers, std::set<std::string>> {
				static constexpr const char* const name = "context-identifiers";
				static constexpr const char* const description = "Currently option has no effect.";
			};

			enum OutputDimensionalityTypes {
				CURVES,
				SURFACES_AND_SOLIDS,
				CURVES_SURFACES_AND_SOLIDS
			};

			IFC_GEOM_API std::istream& operator>>(std::istream& in, OutputDimensionalityTypes& ioo);

			struct OutputDimensionality : public SettingBase<OutputDimensionality, OutputDimensionalityTypes> {
				static constexpr const char* const name = "dimensionality";
				static constexpr const char* const description =
					"Specifies whether to include curves and/or surfaces and solids in the output result. "
					"Defaults to only surfaces and solids (SURFACES_AND_SOLIDS). "
					"Other possible values are CURVES, CURVES_SURFACES_AND_SOLIDS.";
				static constexpr OutputDimensionalityTypes defaultvalue = SURFACES_AND_SOLIDS;
			};

			enum IteratorOutputOptions {
				TRIANGULATED,
				NATIVE,
				SERIALIZED
			};

			IFC_GEOM_API std::istream& operator>>(std::istream& in, IteratorOutputOptions& ioo);

			struct IteratorOutput : public SettingBase<IteratorOutput, IteratorOutputOptions> {
				static constexpr const char* const name = "iterator-output";
				static constexpr const char* const description = "";
				static constexpr IteratorOutputOptions defaultvalue = TRIANGULATED;
			};

			struct DisableOpeningSubtractions : public SettingBase<DisableOpeningSubtractions, bool> {
				static constexpr const char* const name = "disable-opening-subtractions";
				static constexpr const char* const description = "Specifies whether to disable the boolean subtraction of "
					"IfcOpeningElement Representations from their RelatingElements.";
				static constexpr bool defaultvalue = false;
			};

			struct ApplyDefaultMaterials : public SettingBase<ApplyDefaultMaterials, bool> {
				static constexpr const char* const name = "apply-default-materials";
				static constexpr const char* const description = "";
				static constexpr bool defaultvalue = true;
			};

			struct DontEmitNormals : public SettingBase<DontEmitNormals, bool> {
				static constexpr const char* const name = "no-normals";
				static constexpr const char* const description = "Disables computation of normals.Saves time and file size and is useful "
					"in instances where you're going to recompute normals for the exported "
					"model in other modelling application in any case.";
				static constexpr bool defaultvalue = false;
			};

			struct GenerateUvs : public SettingBase<GenerateUvs, bool> {
				static constexpr const char* const name = "generate-uvs";
				static constexpr const char* const description = "Generates UVs (texture coordinates) by using simple box projection. Requires normals. "
					"Not guaranteed to work properly if used with --weld-vertices.";
				static constexpr bool defaultvalue = false;
			};

			struct ApplyLayerSets : public SettingBase<ApplyLayerSets, bool> {
				static constexpr const char* const name = "enable-layerset-slicing";
				static constexpr const char* const description = "Specifies whether to enable the slicing of products according "
					"to their associated IfcMaterialLayerSet.";
				static constexpr bool defaultvalue = false;
			};

			struct UseElementHierarchy : public SettingBase<UseElementHierarchy, bool> {
				static constexpr const char* const name = "element-hierarchy";
				static constexpr const char* const description = "Assign the elements using their e.g IfcBuildingStorey parent."
					"Applicable to DAE output.";
				static constexpr bool defaultvalue = false;
			};

			struct ValidateQuantities : public SettingBase<ValidateQuantities, bool> {
				static constexpr const char* const name = "validate";
				static constexpr const char* const description = "Checks whether geometrical output conforms to the included explicit quantities.";
				static constexpr bool defaultvalue = false;
			};

			struct EdgeArrows : public SettingBase<EdgeArrows, bool> {
				static constexpr const char* const name = "edge-arrows";
				static constexpr const char* const description = "Adds arrow heads to edge segments to signify edge direction";
				static constexpr bool defaultvalue = false;
			};

			struct SiteLocalPlacement : public SettingBase<SiteLocalPlacement, bool> {
				static constexpr const char* const name = "site-local-placement";
				static constexpr const char* const description = "Place elements locally in the IfcSite coordinate system, instead of placing "
					"them in the IFC global coords. Applicable for OBJ, DAE, and STP output.";
				static constexpr bool defaultvalue = false;
			};

			struct BuildingLocalPlacement : public SettingBase<BuildingLocalPlacement, bool> {
				static constexpr const char* const name = "building-local-placement";
				static constexpr const char* const description = "Similar to --site-local-placement, but placing elements in locally in the parent IfcBuilding coord system";
				static constexpr bool defaultvalue = false;
			};

			struct NoParallelMapping : public SettingBase<NoParallelMapping, bool> {
				static constexpr const char* const name = "no-parallel-mapping";
				static constexpr const char* const description = "Perform mapping upfront (single-threaded) as opposed to in parallel. May decrease performance, but also decrease output size (in the future)";
				static constexpr bool defaultvalue = false;
			};

			struct PermissiveShapeReuse : public SettingBase<PermissiveShapeReuse, bool> {
				static constexpr const char* const name = "permissive-shape-reuse";
				static constexpr const char* const description = "Traverse geometry-level transformations and apply to product-level placement in order to increase reuse of geometries";
				static constexpr bool defaultvalue = false;
			};

			struct ForceSpaceTransparency : public SettingBase<ForceSpaceTransparency, double> {
				static constexpr const char* const name = "force-space-transparency";
				static constexpr const char* const description = "Overrides transparency of spaces in geometry output.";
			};

			struct CircleSegments : public SettingBase<CircleSegments, int> {
				static constexpr const char* const name = "circle-segments";
				static constexpr const char* const description = "Number of segments to approximate full circles in the CGAL kernel. When 0 (the default) the segment count is derived from mesher-linear-deflection instead, so curves stay within the deflection tolerance regardless of radius.";
				static constexpr int defaultvalue = 0;
			};

			struct CgalSmoothAngleDegrees : public SettingBase<CgalSmoothAngleDegrees, double> {
				static constexpr const char* const name = "cgal-smooth-angle-degrees";
				static constexpr const char* const description = "Angle in degrees under which adjacent facets will have averaged vertex normals in CGAL output. NB irrespective of original IFC geometry types. Defaults to -1 to disable smoothing.";
				static constexpr double defaultvalue = -1.;
			};

			struct SvgRidgeAngleMinDegrees : public SettingBase<SvgRidgeAngleMinDegrees, double> {
				static constexpr const char* const name = "svg-ridge-angle-min-degrees";
				static constexpr const char* const description = "SVG edge classification (issue #3668): minimum convex dihedral deviation from flat, in degrees, for a projection edge to be classified as 'sharp' rather than 'flush'.";
				static constexpr double defaultvalue = 45.;
			};

			struct SvgValleyAngleMinDegrees : public SettingBase<SvgValleyAngleMinDegrees, double> {
				static constexpr const char* const name = "svg-valley-angle-min-degrees";
				static constexpr const char* const description = "SVG edge classification (issue #3668): minimum concave dihedral deviation from flat, in degrees, for a projection edge to be classified as 'crease' rather than 'flush'.";
				static constexpr double defaultvalue = 12.;
			};

			struct SvgEmitFlushEdges : public SettingBase<SvgEmitFlushEdges, bool> {
				static constexpr const char* const name = "svg-emit-flush-edges";
				static constexpr const char* const description = "SVG edge classification (issue #3668): whether to emit 'flush' projection edges (dihedral deviation below both ridge/valley thresholds). Defaults to false, i.e. flush edges are omitted from the output.";
				static constexpr bool defaultvalue = false;
			};

			struct SvgUseEdgeClassification : public SettingBase<SvgUseEdgeClassification, bool> {
				static constexpr const char* const name = "svg-use-edge-classification";
				static constexpr const char* const description = "SVG edge classification (issue #3668): enable the 5-class boundary/outline/sharp/crease/flush scheme. When false (the default), falls back to the original unclassified linework.";
				static constexpr bool defaultvalue = false;
			};

			struct SvgRenderCreaseEdges : public SettingBase<SvgRenderCreaseEdges, bool> {
				static constexpr const char* const name = "svg-render-crease-edges";
				static constexpr const char* const description = "SVG edge classification (issue #3668): whether to emit 'crease' (concave) projection edges. Only relevant when svg-use-edge-classification is enabled.";
				static constexpr bool defaultvalue = true;
			};

			struct SvgRenderSharpEdges : public SettingBase<SvgRenderSharpEdges, bool> {
				static constexpr const char* const name = "svg-render-sharp-edges";
				static constexpr const char* const description = "SVG edge classification (issue #3668): whether to emit 'sharp' (convex) projection edges. Only relevant when svg-use-edge-classification is enabled.";
				static constexpr bool defaultvalue = true;
			};

			struct KeepBoundingBoxes : public SettingBase<KeepBoundingBoxes, bool> {
				static constexpr const char* const name = "keep-bounding-boxes";
				static constexpr const char* const description =
					"Default is to removes IfcBoundingBox from model prior to converting geometry."
					"Setting this option disables that behaviour";
				static constexpr bool defaultvalue = false;
			};

			struct SurfaceColour : public SettingBase<SurfaceColour, bool> {
                static constexpr const char* const name = "surface-colour";
                static constexpr const char* const description =
                    "Prioritizes the surface color instead of using diffuse.";
                static constexpr bool defaultvalue = false;
            };

            struct ComputeCurvature : public SettingBase<ComputeCurvature, bool> {
                static constexpr const char* const name = "compute-curvature";
                static constexpr const char* const description = "Specifies whether function_item_evaluator.evaluate() computes curvature.";
                static constexpr bool defaultvalue = false;
            };

			enum FunctionStepMethod  {
				MAXSTEPSIZE,
				MINSTEPS };

			IFC_GEOM_API std::istream& operator>>(std::istream& in, FunctionStepMethod& ioo);

         struct FunctionStepType : public SettingBase<FunctionStepType, FunctionStepMethod> {
               static constexpr const char* const name = "function-step-type";
               static constexpr const char* const description = "Indicates the method used for defining step size when evaluating function-based curves. Provides interpretation of function-step-param";
               static constexpr FunctionStepMethod defaultvalue = MAXSTEPSIZE;
         };

			struct FunctionStepParam : public SettingBase<FunctionStepParam, double> {
               static constexpr const char* const name = "function-step-param";
               static constexpr const char* const description = "Indicates the parameter value for defining step size when evaluating function-based curves.";
               static constexpr double defaultvalue = 0.5; // ceiling of this value is used when FunctionStepMethod is MinSteps
         };

			struct ModelOffset : public SettingBase<ModelOffset, std::vector<double>> {
				static constexpr const char* const name = "model-offset";
				static constexpr const char* const description = "Applies an arbitrary offset of form x,y,z to all placements.";
			};

			struct ModelRotation : public SettingBase<ModelRotation, std::vector<double>> {
				static constexpr const char* const name = "model-rotation";
				static constexpr const char* const description = "Applies an arbitrary quaternion rotation of form x,y,z,w to all placements.";
			};

			enum TriangulationMethod {
				TRIANGLE_MESH,
				POLYHEDRON_WITHOUT_HOLES,
				POLYHEDRON_WITH_HOLES
			};

			IFC_GEOM_API std::istream& operator>>(std::istream& in, TriangulationMethod& ioo);

			struct TriangulationType : public SettingBase<TriangulationType, TriangulationMethod> {
				static constexpr const char* const name = "triangulation-type";
				static constexpr const char* const description = "Type of planar facet to be emitted";
				static constexpr TriangulationMethod defaultvalue = TRIANGLE_MESH;
			};

			struct CgalEmitOriginalEdges : public SettingBase<CgalEmitOriginalEdges, bool> {
				static constexpr const char* const name = "cgal-original-edges";
				static constexpr const char* const description = "Try to emit original edge face boundary edges instead of recomputed ones based on face normal. Falls back to triangulated data in case of boolean operands and faces with holes.";
				static constexpr bool defaultvalue = false;
			};

			struct OcctNoCleanTriangulation : public SettingBase<OcctNoCleanTriangulation, bool, true> {
				static constexpr const char* const name = "no-clean-triangulation";
				static constexpr const char* const description = "Don't clean triangulations, might cause memory leaks";
				static constexpr bool defaultvalue = false;
			};

			struct CacheShapes : public SettingBase<CacheShapes, bool> {
				static constexpr const char* const name = "cache-shapes";
				static constexpr const char* const description = "Experimental as not all topology hash functions fully implemented";
				static constexpr bool defaultvalue = false;
			};

			struct MakeVolume : public SettingBase<MakeVolume, bool> {
                static constexpr const char* const name = "make-volume";
                static constexpr const char* const description = "Try to isolate and fix a valid volume from non-manifold elements prior to opening subtraction";
                static constexpr bool defaultvalue = false;
            };

			struct DeferProcessingFirstElement : public SettingBase<DeferProcessingFirstElement, bool, true> {
				static constexpr const char* const name = "defer-processing-first-element";
				static constexpr const char* const description = "Don't process first element in Iterator::initialize call()";
				static constexpr bool defaultvalue = false;
			};

			struct MaxOffset : public SettingBase<MaxOffset, double> {
				static constexpr const char* const name = "max-offset";
				static constexpr const char* const description = "Maximum translation offset to be observed after which median offset in model gets removed and logged. Requires --no-parallel-mapping.";
			};

			struct MaxOffsetDeviation : public SettingBase<MaxOffsetDeviation, double> {
				static constexpr const char* const name = "max-offset-deviation";
				static constexpr const char* const description = "To retain field of view, completely remove elements outside of the median offset. Requires --no-parallel-mapping.";
			};

			struct ApplyOffset : public SettingBase<ApplyOffset, std::vector<double>> {
				static constexpr const char* const name = "apply-offset";
				static constexpr const char* const description = "Slight variation of --model-offset where large offsets are applied by negating existing large offsets to retain maximum precision. Requires --no-parallel-mapping.";
			};
		}
		
		namespace impl {
			template <typename T>
			struct readable_name {
				static constexpr const char* name = "Unknown Type";
			};

			template <>
			struct readable_name<bool> {
				static constexpr const char* name = "bool";
			};

			template <>
			struct readable_name<int> {
				static constexpr const char* name = "int";
			};

			template <>
			struct readable_name<double> {
				static constexpr const char* name = "double";
			};

			template <>
			struct readable_name<std::string> {
				static constexpr const char* name = "std::string";
			};

			template <>
			struct readable_name<std::set<int>> {
				static constexpr const char* name = "std::set<int>";
			};

			template <>
			struct readable_name<std::set<std::string>> {
				static constexpr const char* name = "std::set<std::string>";
			};

			template <>
			struct readable_name<std::vector<double>> {
				static constexpr const char* name = "std::vector<double>";
			};

			template <>
			struct readable_name<IteratorOutputOptions> {
				static constexpr const char* name = "IteratorOutputOptions";
			};

			template <>
			struct readable_name<FunctionStepMethod> {
				static constexpr const char* name = "FunctionStepMethod";
			};

			template <>
			struct readable_name<OutputDimensionalityTypes> {
				static constexpr const char* name = "OutputDimensionalityTypes";
			};

			template <>
			struct readable_name<TriangulationMethod> {
				static constexpr const char* name = "TriangulationMethod";
			};
		}

		template <typename settings_t>
		class SettingsContainer {
		public:
         typedef boost::variant<bool, int, double, std::string, std::set<int>, std::set<std::string>, std::vector<double>, IteratorOutputOptions, FunctionStepMethod, OutputDimensionalityTypes, TriangulationMethod> value_variant_t;
		private:
			settings_t settings;

			template <std::size_t Index>
			void define_options_(po::options_description& desc) {
				std::get<Index>(settings).defineOption(desc);
				if constexpr (Index + 1 < std::tuple_size_v<settings_t>) {
					define_options_<Index + 1>(desc);
				}
			}

			template <std::size_t Index>
			value_variant_t get_option_(const std::string& name) const {
				if (std::tuple_element_t<Index, settings_t>::name == name) {
					return std::get<Index>(settings).get();
				}
				if constexpr (Index + 1 < std::tuple_size_v<settings_t>) {
					return get_option_<Index + 1>(name);
				} else {
					throw std::runtime_error("Setting not available");
				}
			}

			template <std::size_t Index>
			std::string get_type_(const std::string& name) const {
				if (std::tuple_element_t<Index, settings_t>::name == name) {
					return impl::readable_name<typename std::tuple_element_t<Index, settings_t>::base_type>::name;
				}
				if constexpr (Index + 1 < std::tuple_size_v<settings_t>) {
					return get_type_<Index + 1>(name);
				} else {
					throw std::runtime_error("Setting not available");
				}
			}

			template <std::size_t Index>
			void set_option_(const std::string& name, const value_variant_t& val) {
				if (std::tuple_element_t<Index, settings_t>::name == name) {
					if constexpr (std::is_enum_v<typename std::tuple_element_t<Index, settings_t>::base_type>) {
						if (auto* val_ptr = boost::get<int>(&val)) {
							auto val_as_enum = (typename std::tuple_element_t<Index, settings_t>::base_type) *val_ptr;
							std::get<Index>(settings).value = val_as_enum;
							return;
						}
					}
					try {
						std::get<Index>(settings).value = boost::get<typename std::tuple_element_t<Index, settings_t>::base_type>(val);
					} catch (const boost::bad_get&) {
						std::string ty = impl::readable_name<typename std::tuple_element_t<Index, settings_t>::base_type>::name;
						throw std::runtime_error("Expected a value of type <" + ty + "> for setting '" + name + "'");
					}
				} else if constexpr (Index + 1 < std::tuple_size_v<settings_t>) {
					set_option_<Index + 1>(name, val);
				} else {
					throw std::runtime_error("Setting not available");
				}
			}

			template <std::size_t Index>
			void get_setting_names_(std::vector<std::string>& vec) const {
				vec.push_back(std::tuple_element_t<Index, settings_t>::name);
				if constexpr (Index + 1 < std::tuple_size_v<settings_t>) {
					return get_setting_names_<Index + 1>(vec);
				}
			}
		public:
			typedef settings_t settings_tuple;

			void define_options(po::options_description& desc) {
				define_options_<0>(desc);
			}

			template <typename T>
			const T& get() const {
				return std::get<T>(settings);
			}

			template <typename T>
			T& get() {
				return std::get<T>(settings);
			}

			template <typename T>
			void set(T& v) {
				std::get<T>(settings) = v;
			}

			value_variant_t get(const std::string& name) const {
				return get_option_<0>(name);
			}

			void set(const std::string& name, value_variant_t val) {
				set_option_<0>(name, val);
			}

			std::string get_type(const std::string& name) {
				return get_type_<0>(name);
			}

			std::vector<std::string> setting_names() const {
				std::vector<std::string> r;
				get_setting_names_<0>(r);
				return r;
			}
		};

		class Settings : public SettingsContainer<
                             std::tuple<MesherLinearDeflection, MesherAngularDeflection, ReorientShells, LengthUnit, PlaneUnit, Precision, OutputDimensionality, LayersetFirst, DisableBooleanResult, NoWireIntersectionCheck, NoWireIntersectionTolerance, PrecisionFactor, DebugBooleanOperations, BooleanAttempt2d, SurfaceColour, WeldVertices, UseWorldCoords, UnifyShapes, UseMaterialNames, ConvertBackUnits, ContextIds, ContextTypes, ContextIdentifiers, IteratorOutput, DisableOpeningSubtractions, ApplyDefaultMaterials, DontEmitNormals, GenerateUvs, ApplyLayerSets, UseElementHierarchy, ValidateQuantities, EdgeArrows, BuildingLocalPlacement, SiteLocalPlacement, ForceSpaceTransparency, CircleSegments, CgalSmoothAngleDegrees, SvgRidgeAngleMinDegrees, SvgValleyAngleMinDegrees, SvgEmitFlushEdges, SvgUseEdgeClassification, SvgRenderCreaseEdges, SvgRenderSharpEdges, KeepBoundingBoxes, ComputeCurvature, FunctionStepType, FunctionStepParam, NoParallelMapping, PermissiveShapeReuse, ModelOffset, ModelRotation, TriangulationType, CgalEmitOriginalEdges, OcctNoCleanTriangulation, CacheShapes, DeferProcessingFirstElement, MaxOffset, MaxOffsetDeviation, ApplyOffset, MakeVolume>
		>
		{};
}
}

// @todo find a place
namespace IfcGeom {

#if defined(_MSC_VER)
#pragma warning(push)
#pragma warning(disable: 4275)
#endif

	class IFC_GEOM_API geometry_exception : public std::runtime_error {
	protected:
		std::string message;
	public:
		geometry_exception(const std::string& m)
			: std::runtime_error(m)
		{}
		~geometry_exception() override;
	};

	class IFC_GEOM_API too_many_faces_exception : public geometry_exception {
	public:
		too_many_faces_exception()
			: geometry_exception("Too many faces for operation") {}
		~too_many_faces_exception() override;
	};
}

#if defined(_MSC_VER)
#pragma warning(pop)
#endif

#endif