Source/Gorgon/Struct.h

#pragma once

#include <typeinfo>
#include "TMP.h"

namespace Gorgon {
	
	template <int N, class ...T_>
	struct GetElm {
	};
	
	template <class T1_, class ...T_>
	struct GetElm<0, T1_, T_...> {
		template <T1_ V1_, T_ ...V_>
		struct Inner {
			static constexpr T1_ Value = V1_;
		};
	};
	
	template <int N, class T1_, class ...T_>
	struct GetElm<N, T1_, T_...> {
		template <T1_ V1_, T_ ...V_>
		struct Inner {
			static constexpr auto Value = GetElm<N-1, T_...>::template Inner<V_...>::Value;
		};
	};
    
	
	template<class C_, class ...MT_>
	class StructDefiner {
	public:
		template<MT_ ...M_>
		struct Inner {
			
			template<class ...S_>
			constexpr Inner(const S_ &...names) : Names{names...} {
				static_assert(sizeof...(S_) == sizeof...(MT_), "Number of element names does not match with the number of elements");
			}
			
			template<int N>
			struct Member {
				using Type = typename TMP::RemoveRValueReference<decltype(std::declval<C_>().*(GetElm<N, MT_...>::template Inner<M_...>::Value))>::Type;

				static constexpr decltype(GetElm<N, MT_...>::template Inner<M_...>::Value) 
				MemberPointer() {
					return std::get<N>(std::tuple<MT_...>(M_...));
				}
			};
			
			const char *Names[sizeof...(MT_)];

			static constexpr int MemberCount = sizeof...(MT_);
			
			static constexpr int IsGorgonReflection = true;
		};
	};


#ifdef _MSC_VER
	#define CALLER(F, P)    CALL_(F, P)
	#define CALL_(F, P)     F##P

	#define CONC(A, B)       CONC_(A, B)
	#define CONC_(A, B)      CONC__(A, B)
	#define CONC__(A, B)     CONC___(A, B)
	#define CONC___(A, B)    CONC____(A, B)
	#define CONC____(A, B)   CONC_____(A, B)
	#define CONC_____(A, B)  CONC______(A, B)
	#define CONC______(A, B) A##B

	#define NARGS(...) CALL_(NARGS_,(__VA_ARGS__, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0))
	#define NARGS_(_16, _15, _14, _13, _12, _11, _10, _9, _8, _7, _6, _5, _4, _3, _2, _1, N, ...) N


	#define StructDefiner_types_1(C, E)       decltype(&C::E)
	#define StructDefiner_types_2(C, E, F)    decltype(&C::E),       StructDefiner_types_1   (C, F)
	#define StructDefiner_types_3(C, E, ...)  decltype(&C::E), CALL_(StructDefiner_types_2 , (C, __VA_ARGS__))
	#define StructDefiner_types_4(C, E, ...)  decltype(&C::E), CALL_(StructDefiner_types_3 , (C, __VA_ARGS__))
	#define StructDefiner_types_5(C, E, ...)  decltype(&C::E), CALL_(StructDefiner_types_4 , (C, __VA_ARGS__))
	#define StructDefiner_types_6(C, E, ...)  decltype(&C::E), CALL_(StructDefiner_types_5 , (C, __VA_ARGS__))
	#define StructDefiner_types_7(C, E, ...)  decltype(&C::E), CALL_(StructDefiner_types_6 , (C, __VA_ARGS__))
	#define StructDefiner_types_8(C, E, ...)  decltype(&C::E), CALL_(StructDefiner_types_7 , (C, __VA_ARGS__))
	#define StructDefiner_types_9(C, E, ...)  decltype(&C::E), CALL_(StructDefiner_types_8 , (C, __VA_ARGS__))
	#define StructDefiner_types_10(C, E, ...) decltype(&C::E), CALL_(StructDefiner_types_9 , (C, __VA_ARGS__))
	#define StructDefiner_types_11(C, E, ...) decltype(&C::E), CALL_(StructDefiner_types_10, (C, __VA_ARGS__))
	#define StructDefiner_types_12(C, E, ...) decltype(&C::E), CALL_(StructDefiner_types_11, (C, __VA_ARGS__))
	#define StructDefiner_types_13(C, E, ...) decltype(&C::E), CALL_(StructDefiner_types_12, (C, __VA_ARGS__))
	#define StructDefiner_types_14(C, E, ...) decltype(&C::E), CALL_(StructDefiner_types_13, (C, __VA_ARGS__))
	#define StructDefiner_types_15(C, E, ...) decltype(&C::E), CALL_(StructDefiner_types_14, (C, __VA_ARGS__))
	#define StructDefiner_types_16(C, E, ...) decltype(&C::E), CALL_(StructDefiner_types_15, (C, __VA_ARGS__))

	#define StructDefiner_values_1(C, E)       &C::E
	#define StructDefiner_values_2(C, E, F)    &C::E,       StructDefiner_values_1   (C, F)
	#define StructDefiner_values_3(C, E, ...)  &C::E, CALL_(StructDefiner_values_2 , (C, __VA_ARGS__))
	#define StructDefiner_values_4(C, E, ...)  &C::E, CALL_(StructDefiner_values_3 , (C, __VA_ARGS__))
	#define StructDefiner_values_5(C, E, ...)  &C::E, CALL_(StructDefiner_values_4 , (C, __VA_ARGS__))
	#define StructDefiner_values_6(C, E, ...)  &C::E, CALL_(StructDefiner_values_5 , (C, __VA_ARGS__))
	#define StructDefiner_values_7(C, E, ...)  &C::E, CALL_(StructDefiner_values_6 , (C, __VA_ARGS__))
	#define StructDefiner_values_8(C, E, ...)  &C::E, CALL_(StructDefiner_values_7 , (C, __VA_ARGS__))
	#define StructDefiner_values_9(C, E, ...)  &C::E, CALL_(StructDefiner_values_8 , (C, __VA_ARGS__))
	#define StructDefiner_values_10(C, E, ...) &C::E, CALL_(StructDefiner_values_9 , (C, __VA_ARGS__))
	#define StructDefiner_values_11(C, E, ...) &C::E, CALL_(StructDefiner_values_10, (C, __VA_ARGS__))
	#define StructDefiner_values_12(C, E, ...) &C::E, CALL_(StructDefiner_values_11, (C, __VA_ARGS__))
	#define StructDefiner_values_13(C, E, ...) &C::E, CALL_(StructDefiner_values_12, (C, __VA_ARGS__))
	#define StructDefiner_values_14(C, E, ...) &C::E, CALL_(StructDefiner_values_13, (C, __VA_ARGS__))
	#define StructDefiner_values_15(C, E, ...) &C::E, CALL_(StructDefiner_values_14, (C, __VA_ARGS__))
	#define StructDefiner_values_16(C, E, ...) &C::E, CALL_(StructDefiner_values_15, (C, __VA_ARGS__))
		
	#define StructDefiner_names_1(C, E)       #E
	#define StructDefiner_names_2(C, E, F)    #E,       StructDefiner_names_1   (C, F)
	#define StructDefiner_names_3(C, E, ...)  #E, CALL_(StructDefiner_names_2 , (C, __VA_ARGS__))
	#define StructDefiner_names_4(C, E, ...)  #E, CALL_(StructDefiner_names_3 , (C, __VA_ARGS__))
	#define StructDefiner_names_5(C, E, ...)  #E, CALL_(StructDefiner_names_4 , (C, __VA_ARGS__))
	#define StructDefiner_names_6(C, E, ...)  #E, CALL_(StructDefiner_names_5 , (C, __VA_ARGS__))
	#define StructDefiner_names_7(C, E, ...)  #E, CALL_(StructDefiner_names_6 , (C, __VA_ARGS__))
	#define StructDefiner_names_8(C, E, ...)  #E, CALL_(StructDefiner_names_7 , (C, __VA_ARGS__))
	#define StructDefiner_names_9(C, E, ...)  #E, CALL_(StructDefiner_names_8 , (C, __VA_ARGS__))
	#define StructDefiner_names_10(C, E, ...) #E, CALL_(StructDefiner_names_9 , (C, __VA_ARGS__))
	#define StructDefiner_names_11(C, E, ...) #E, CALL_(StructDefiner_names_10, (C, __VA_ARGS__))
	#define StructDefiner_names_12(C, E, ...) #E, CALL_(StructDefiner_names_11, (C, __VA_ARGS__))
	#define StructDefiner_names_13(C, E, ...) #E, CALL_(StructDefiner_names_12, (C, __VA_ARGS__))
	#define StructDefiner_names_14(C, E, ...) #E, CALL_(StructDefiner_names_13, (C, __VA_ARGS__))
	#define StructDefiner_names_15(C, E, ...) #E, CALL_(StructDefiner_names_14, (C, __VA_ARGS__))
	#define StructDefiner_names_16(C, E, ...) #E, CALL_(StructDefiner_names_15, (C, __VA_ARGS__))

	/// Defines a struct members with the given name. The first parameter is the name of the class.
	/// This macro should be called inside the class/struct scope. This reflection is geared towards
	/// POD objects. Might not behave as intented on polymorphic objects. After calling this function
	/// the class will have ReflectionType and Reflection() that returns reflection object with names.
	#define DefineStructMembers(C, ...) \
		using ReflectionType = StructDefiner<C, CALLER(CALL_(CONC, (StructDefiner_types_, CONC(NARGS,(__VA_ARGS__))) ),(C, __VA_ARGS__))>::\
		Inner<CALLER(CALL_(CONC, (StructDefiner_values_, CONC(NARGS,(__VA_ARGS__))) ),(C, __VA_ARGS__))>; \
		static constexpr ReflectionType Reflection() { return {CALLER(CALL_(CONC, (StructDefiner_names_, CONC(NARGS,(__VA_ARGS__))) ),(C, __VA_ARGS__))}; }
		
		
	/// Defines a struct members with the given name. The first parameter is the name of the class.
	/// This macro should be called inside the class/struct scope. This reflection is geared towards
	/// POD objects. Might not behave as intented on polymorphic objects. This variant allows naming
	/// Reflection object function and type. After calling this function the class will have 
	/// {Name}Type and {Name}() that returns reflection object with names.
	#define DefineStructMembersWithName(C, Name, ...) \
		using Name##Type = StructDefiner<C, CALLER(CALL_(CONC, (StructDefiner_types_, CONC(NARGS,(__VA_ARGS__))) ),(C, __VA_ARGS__))>::\
		Inner<CALLER(CALL_(CONC, (StructDefiner_values_, CONC(NARGS,(__VA_ARGS__))) ),(C, __VA_ARGS__))>; \
		static constexpr Name##Type Name() { return {CALLER(CALL_(CONC, (StructDefiner_names_, CONC(NARGS,(__VA_ARGS__))) ),(C, __VA_ARGS__))}; }
#else
	#define CONC(A, B) CONC_(A, B)
	#define CONC_(A, B) A##B
	#define NARGS(...) NARGS_(__VA_ARGS__, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0)
	#define NARGS_(_16, _15, _14, _13, _12, _11, _10, _9, _8, _7, _6, _5, _4, _3, _2, _1, N, ...) N
	
	#define StructDefiner_types_1(C, E) decltype(&C::E)
	#define StructDefiner_types_2(C, E, ...) decltype(&C::E), StructDefiner_types_1(C, __VA_ARGS__)
	#define StructDefiner_types_3(C, E, ...) decltype(&C::E), StructDefiner_types_2(C, __VA_ARGS__)
	#define StructDefiner_types_4(C, E, ...) decltype(&C::E), StructDefiner_types_3(C, __VA_ARGS__)
	#define StructDefiner_types_5(C, E, ...) decltype(&C::E), StructDefiner_types_4(C, __VA_ARGS__)
	#define StructDefiner_types_6(C, E, ...) decltype(&C::E), StructDefiner_types_5(C, __VA_ARGS__)
	#define StructDefiner_types_7(C, E, ...) decltype(&C::E), StructDefiner_types_6(C, __VA_ARGS__)
	#define StructDefiner_types_8(C, E, ...) decltype(&C::E), StructDefiner_types_7(C, __VA_ARGS__)
	#define StructDefiner_types_9(C, E, ...) decltype(&C::E), StructDefiner_types_8(C, __VA_ARGS__)
	#define StructDefiner_types_10(C, E, ...) decltype(&C::E), StructDefiner_types_9(C, __VA_ARGS__)
	#define StructDefiner_types_11(C, E, ...) decltype(&C::E), StructDefiner_types_10(C, __VA_ARGS__)
	#define StructDefiner_types_12(C, E, ...) decltype(&C::E), StructDefiner_types_11(C, __VA_ARGS__)
	#define StructDefiner_types_13(C, E, ...) decltype(&C::E), StructDefiner_types_12(C, __VA_ARGS__)
	#define StructDefiner_types_14(C, E, ...) decltype(&C::E), StructDefiner_types_13(C, __VA_ARGS__)
	#define StructDefiner_types_15(C, E, ...) decltype(&C::E), StructDefiner_types_14(C, __VA_ARGS__)
	#define StructDefiner_types_16(C, E, ...) decltype(&C::E), StructDefiner_types_15(C, __VA_ARGS__)

	#define StructDefiner_values_1(C, E) &C::E
	#define StructDefiner_values_2(C, E, ...) &C::E, StructDefiner_values_1(C, __VA_ARGS__)
	#define StructDefiner_values_3(C, E, ...) &C::E, StructDefiner_values_2(C, __VA_ARGS__)
	#define StructDefiner_values_4(C, E, ...) &C::E, StructDefiner_values_3(C, __VA_ARGS__)
	#define StructDefiner_values_5(C, E, ...) &C::E, StructDefiner_values_4(C, __VA_ARGS__)
	#define StructDefiner_values_6(C, E, ...) &C::E, StructDefiner_values_5(C, __VA_ARGS__)
	#define StructDefiner_values_7(C, E, ...) &C::E, StructDefiner_values_6(C, __VA_ARGS__)
	#define StructDefiner_values_8(C, E, ...) &C::E, StructDefiner_values_7(C, __VA_ARGS__)
	#define StructDefiner_values_9(C, E, ...) &C::E, StructDefiner_values_8(C, __VA_ARGS__)
	#define StructDefiner_values_10(C, E, ...) &C::E, StructDefiner_values_9(C, __VA_ARGS__)
	#define StructDefiner_values_11(C, E, ...) &C::E, StructDefiner_values_10(C, __VA_ARGS__)
	#define StructDefiner_values_12(C, E, ...) &C::E, StructDefiner_values_11(C, __VA_ARGS__)
	#define StructDefiner_values_13(C, E, ...) &C::E, StructDefiner_values_12(C, __VA_ARGS__)
	#define StructDefiner_values_14(C, E, ...) &C::E, StructDefiner_values_13(C, __VA_ARGS__)
	#define StructDefiner_values_15(C, E, ...) &C::E, StructDefiner_values_14(C, __VA_ARGS__)
	#define StructDefiner_values_16(C, E, ...) &C::E, StructDefiner_values_15(C, __VA_ARGS__)
		
	#define StructDefiner_names_1(C, E) #E
	#define StructDefiner_names_2(C, E, ...) #E, StructDefiner_names_1(C, __VA_ARGS__)
	#define StructDefiner_names_3(C, E, ...) #E, StructDefiner_names_2(C, __VA_ARGS__)
	#define StructDefiner_names_4(C, E, ...) #E, StructDefiner_names_3(C, __VA_ARGS__)
	#define StructDefiner_names_5(C, E, ...) #E, StructDefiner_names_4(C, __VA_ARGS__)
	#define StructDefiner_names_6(C, E, ...) #E, StructDefiner_names_5(C, __VA_ARGS__)
	#define StructDefiner_names_7(C, E, ...) #E, StructDefiner_names_6(C, __VA_ARGS__)
	#define StructDefiner_names_8(C, E, ...) #E, StructDefiner_names_7(C, __VA_ARGS__)
	#define StructDefiner_names_9(C, E, ...) #E, StructDefiner_names_8(C, __VA_ARGS__)
	#define StructDefiner_names_10(C, E, ...) #E, StructDefiner_names_9(C, __VA_ARGS__)
	#define StructDefiner_names_11(C, E, ...) #E, StructDefiner_names_10(C, __VA_ARGS__)
	#define StructDefiner_names_12(C, E, ...) #E, StructDefiner_names_11(C, __VA_ARGS__)
	#define StructDefiner_names_13(C, E, ...) #E, StructDefiner_names_12(C, __VA_ARGS__)
	#define StructDefiner_names_14(C, E, ...) #E, StructDefiner_names_13(C, __VA_ARGS__)
	#define StructDefiner_names_15(C, E, ...) #E, StructDefiner_names_14(C, __VA_ARGS__)
	#define StructDefiner_names_16(C, E, ...) #E, StructDefiner_names_15(C, __VA_ARGS__)
	
	/// Defines a struct members with the given name. The first parameter is the name of the class.
	/// This macro should be called inside the class/struct scope. This reflection is geared towards
	/// POD objects. Might not behave as intented on polymorphic objects. After calling this function
	/// the class will have ReflectionType and Reflection() that returns reflection object with names.
	#define DefineStructMembers(C, ...) using ReflectionType = Gorgon::StructDefiner<C, CONC(StructDefiner_types_, NARGS(__VA_ARGS__)) (C, __VA_ARGS__)>::Inner<CONC(StructDefiner_values_, NARGS(__VA_ARGS__)) (C, __VA_ARGS__)>; \
		static constexpr ReflectionType Reflection() { return {CONC(StructDefiner_names_, NARGS(__VA_ARGS__))(C, __VA_ARGS__)}; }
 
	/// Defines a struct members with the given name. The first parameter is the name of the class.
	/// This macro should be called inside the class/struct scope. This reflection is geared towards
	/// POD objects. Might not behave as intented on polymorphic objects. This variant allows naming
	/// Reflection object function and type. After calling this function the class will have 
	/// {Name}Type and {Name}() that returns reflection object with names.
	#define DefineStructMembersWithName(C, Name, ...) using Name##Type = Gorgon::StructDefiner<C, CONC(StructDefiner_types_, NARGS(__VA_ARGS__)) (C, __VA_ARGS__)>::Inner<CONC(StructDefiner_values_, NARGS(__VA_ARGS__)) (C, __VA_ARGS__)>; \
		static constexpr Name##Type Name() { return {CONC(StructDefiner_names_, NARGS(__VA_ARGS__))(C, __VA_ARGS__)}; }

#endif

}