direct_production.hpp

#include <iterator>
#include <vector>

#ifndef _MSC_VER
#define __forceinline  __attribute__((always_inline))
#endif

template <int N>
struct unit
{
private:
	struct tag {};
	__forceinline
		static const tag& instance() 
	{
		static tag a;
		return a;
	}
public:
	typedef const tag* iterator;
	__forceinline
		static iterator begin()
	{
		return &instance();
	}
	__forceinline
		static iterator end()
	{
		return &instance() + 1;
	}
};

template <class InputIt0 
,class InputIt1
,class InputIt2 = typename unit<2>::iterator
,class InputIt3 = typename unit<3>::iterator
,class InputIt4 = typename unit<4>::iterator
,class InputIt5 = typename unit<5>::iterator
,class InputIt6 = typename unit<6>::iterator
,class InputIt7 = typename unit<7>::iterator
,class InputIt8 = typename unit<8>::iterator
,class InputIt9 = typename unit<9>::iterator
>
class direct_production
{
	InputIt0 itr0_begin;	InputIt0 itr0_end;
	InputIt1 itr1_begin;	InputIt1 itr1_end;
	InputIt2 itr2_begin;	InputIt2 itr2_end;
	InputIt3 itr3_begin;	InputIt3 itr3_end;
	InputIt4 itr4_begin;	InputIt4 itr4_end;
	InputIt5 itr5_begin;	InputIt5 itr5_end;
	InputIt6 itr6_begin;	InputIt6 itr6_end;
	InputIt7 itr7_begin;	InputIt7 itr7_end;
	InputIt8 itr8_begin;	InputIt8 itr8_end;
	InputIt9 itr9_begin;	InputIt9 itr9_end;
private:
	direct_production();
public:
	direct_production(
		InputIt0 itr0_begin,		InputIt0 itr0_end
		,InputIt1 itr1_begin,		InputIt1 itr1_end
		,InputIt2 itr2_begin = unit<2>::begin(),		InputIt2 itr2_end = unit<2>::end()
		,InputIt3 itr3_begin = unit<3>::begin(),		InputIt3 itr3_end = unit<3>::end()
		,InputIt4 itr4_begin = unit<4>::begin(),		InputIt4 itr4_end = unit<4>::end()
		,InputIt5 itr5_begin = unit<5>::begin(),		InputIt5 itr5_end = unit<5>::end()
		,InputIt6 itr6_begin = unit<6>::begin(),		InputIt6 itr6_end = unit<6>::end()
		,InputIt7 itr7_begin = unit<7>::begin(),		InputIt7 itr7_end = unit<7>::end()
		,InputIt8 itr8_begin = unit<8>::begin(),		InputIt8 itr8_end = unit<8>::end()
		,InputIt9 itr9_begin = unit<9>::begin(),		InputIt9 itr9_end = unit<9>::end()
		)
		: itr0_begin(itr0_begin), itr0_end(itr0_end)
		, itr1_begin(itr1_begin), itr1_end(itr1_end)
		, itr2_begin(itr2_begin), itr2_end(itr2_end)
		, itr3_begin(itr3_begin), itr3_end(itr3_end)
		, itr4_begin(itr4_begin), itr4_end(itr4_end)
		, itr5_begin(itr5_begin), itr5_end(itr5_end)
		, itr6_begin(itr6_begin), itr6_end(itr6_end)
		, itr7_begin(itr7_begin), itr7_end(itr7_end)
		, itr8_begin(itr8_begin), itr8_end(itr8_end)
		, itr9_begin(itr9_begin), itr9_end(itr9_end)
	{
	}
	class forward_iterator : std::forward_iterator_tag
	{
		const direct_production &parent;
		InputIt0 itr0_current;
		InputIt1 itr1_current;
		InputIt2 itr2_current;
		InputIt3 itr3_current;
		InputIt4 itr4_current;
		InputIt5 itr5_current;
		InputIt6 itr6_current;
		InputIt7 itr7_current;
		InputIt8 itr8_current;
		InputIt9 itr9_current;
	public:
		forward_iterator(const direct_production &parent
			,InputIt0 itr0_current
			,InputIt1 itr1_current
			,InputIt2 itr2_current
			,InputIt3 itr3_current
			,InputIt4 itr4_current
			,InputIt5 itr5_current
			,InputIt6 itr6_current
			,InputIt7 itr7_current
			,InputIt8 itr8_current
			,InputIt9 itr9_current
			) : parent(parent)
			, itr0_current(itr0_current)
			, itr1_current(itr1_current)
			, itr2_current(itr2_current)
			, itr3_current(itr3_current)
			, itr4_current(itr4_current)
			, itr5_current(itr5_current)
			, itr6_current(itr6_current)
			, itr7_current(itr7_current)
			, itr8_current(itr8_current)
			, itr9_current(itr9_current)
		{
		}
		forward_iterator(const forward_iterator &other)
			: parent(other.parent)
			, itr0_current(other.itr0_current)
			, itr1_current(other.itr1_current)
			, itr2_current(other.itr2_current)
			, itr3_current(other.itr3_current)
			, itr4_current(other.itr4_current)
			, itr5_current(other.itr5_current)
			, itr6_current(other.itr6_current)
			, itr7_current(other.itr7_current)
			, itr8_current(other.itr8_current)
			, itr9_current(other.itr9_current)
		{
		}

		bool operator ==(const forward_iterator &other) const
		{
			return (&parent) == (&other.parent)
				&& itr0_current == other.itr0_current
				&& itr1_current == other.itr1_current
				&& itr2_current == other.itr2_current
				&& itr3_current == other.itr3_current
				&& itr4_current == other.itr4_current
				&& itr5_current == other.itr5_current
				&& itr6_current == other.itr6_current
				&& itr7_current == other.itr7_current
				&& itr8_current == other.itr8_current
				&& itr9_current == other.itr9_current
				;
		}
		bool operator !=(const forward_iterator &other) const
		{
			return !(*this == other);
		}
		forward_iterator &operator++()
		{
			++itr9_current ;
			if (itr9_current != parent.itr9_end )
			{
				goto case9;
			}

			++itr8_current ;
			if (itr8_current != parent.itr8_end )
			{
				goto case8;
			}

			++itr7_current ;
			if (itr7_current != parent.itr7_end )
			{
				goto case7;
			}

			++itr6_current ;
			if (itr6_current != parent.itr6_end )
			{
				goto case6;
			}

			++itr5_current ;
			if (itr5_current != parent.itr5_end )
			{
				goto case5;
			}

			++itr4_current ;
			if (itr4_current != parent.itr4_end )
			{
				goto case4;
			}

			++itr3_current ;
			if (itr3_current != parent.itr3_end )
			{
				goto case3;
			}

			++itr2_current ;
			if (itr2_current != parent.itr2_end )
			{
				goto case2;
			}

			++itr1_current;
			if(itr1_current != parent.itr1_end )
			{
				goto case1;
			}

			++itr0_current;
			if(itr0_current != parent.itr0_end )
			{
				goto case0;
			}

			return *this;
case0:
			itr1_current = parent.itr1_begin;
case1:
			itr2_current = parent.itr2_begin;
case2:
			itr3_current = parent.itr3_begin;
case3:
			itr4_current = parent.itr4_begin;
case4:
			itr5_current = parent.itr5_begin;
case5:
			itr6_current = parent.itr6_begin;
case6:
			itr7_current = parent.itr7_begin;
case7:
			itr8_current = parent.itr8_begin;
case8:
			itr9_current = parent.itr9_begin;
case9:
			return *this;
		}

		forward_iterator operator++(int)
		{
			forward_iterator tmp(*this);
			++(*this);
			return tmp;
		}
		template <size_t index>
		struct index_to_type;

		template <size_t index>
		typename index_to_type<index>::type get() const;

		template <>
		struct index_to_type<0> { typedef InputIt0 type; };
		template <>
		InputIt0 get<0>() const { return itr0_current; }

		template <>
		struct index_to_type<1> { typedef InputIt1 type; };
		template <>
		InputIt1 get<1>() const { return itr1_current; }

		template <>
		struct index_to_type<2> { typedef InputIt2 type; };
		template <>
		InputIt2 get<2>() const { return itr2_current; }

		template <>
		struct index_to_type<3> { typedef InputIt3 type; };
		template <>
		InputIt3 get<3>() const { return itr3_current; }

		template <>
		struct index_to_type<4> { typedef InputIt4 type; };
		template <>
		InputIt4 get<4>() const { return itr4_current; }

		template <>
		struct index_to_type<5> { typedef InputIt5 type; };
		template <>
		InputIt5 get<5>() const { return itr5_current; }

		template <>
		struct index_to_type<6> { typedef InputIt6 type; };
		template <>
		InputIt6 get<6>() const { return itr6_current; }

		template <>
		struct index_to_type<7> { typedef InputIt7 type; };
		template <>
		InputIt7 get<7>() const { return itr7_current; }

		template <>
		struct index_to_type<8> { typedef InputIt8 type; };
		template <>
		InputIt8 get<8>() const { return itr8_current; }

		template <>
		struct index_to_type<9> { typedef InputIt9 type; };
		template <>
		InputIt9 get<9>() const { return itr9_current; }
	};
	typedef forward_iterator itarator;
	forward_iterator begin() const
	{
		return forward_iterator(*this
			, itr0_begin
			, itr1_begin
			, itr2_begin
			, itr3_begin
			, itr4_begin
			, itr5_begin
			, itr6_begin
			, itr7_begin
			, itr8_begin
			, itr9_begin
			);
	}
	forward_iterator end() const
	{
		return forward_iterator(*this
			, itr0_end
			, itr1_end
			, itr2_end
			, itr3_end
			, itr4_end
			, itr5_end
			, itr6_end
			, itr7_end
			, itr8_end
			, itr9_end
			);
	}
};

template <class InputIt0
, class InputIt1
>
direct_production<InputIt0 
, InputIt1
> make_direct_production(InputIt0 itr0_begin, InputIt0 itr0_end
						 , InputIt1 itr1_begin, InputIt1 itr1_end
						 )
{
	return direct_production<InputIt0
		, InputIt1
	>(itr0_begin,itr0_end
	,itr1_begin, itr1_end
	);
}

template <class InputIt0
, class InputIt1
, class InputIt2
>
direct_production<InputIt0 
, InputIt1
, InputIt2
> make_direct_production(InputIt0 itr0_begin, InputIt0 itr0_end
						 , InputIt1 itr1_begin, InputIt1 itr1_end
						 , InputIt2 itr2_begin, InputIt2 itr2_end
						 )
{
	return direct_production<InputIt0
		, InputIt1
		, InputIt2
	>(itr0_begin,itr0_end
	,itr1_begin, itr1_end
	,itr2_begin, itr2_end
	);
}

template <class InputIt0
, class InputIt1
, class InputIt2
, class InputIt3
>
direct_production<InputIt0 
, InputIt1
, InputIt2
, InputIt3
> make_direct_production(InputIt0 itr0_begin, InputIt0 itr0_end
						 , InputIt1 itr1_begin, InputIt1 itr1_end
						 , InputIt2 itr2_begin, InputIt2 itr2_end
						 , InputIt3 itr3_begin, InputIt3 itr3_end
						 )
{
	return direct_production<InputIt0
		, InputIt1
		, InputIt2
		, InputIt3
	>(itr0_begin,itr0_end
	,itr1_begin, itr1_end
	,itr2_begin, itr2_end
	,itr3_begin, itr3_end
	);
}