text: /*=============================================================================
    Copyright (c) 2011-2015 Bolero MURAKAMI
    https://github.com/bolero-MURAKAMI/Sprout
  
    Distributed under the Boost Software License, Version 1.0. (See accompanying
    file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  =============================================================================*/
  #ifndef SPROUT_ITERATOR_PTR_INDEX_ITERATOR_HPP
  #define SPROUT_ITERATOR_PTR_INDEX_ITERATOR_HPP
  
  #include <iterator>
  #include <utility>
  #include <type_traits>
  #include <sprout/config.hpp>
  #include <sprout/iterator/next.hpp>
  #include <sprout/iterator/prev.hpp>
  #include <sprout/iterator/distance.hpp>
  #include <sprout/iterator/detail/iterator_to_pointer.hpp>
  #include <sprout/utility/swap.hpp>
  #include <sprout/type_traits/integral_constant.hpp>
  
  namespace sprout {
  	//
  	// ptr_index_iterator
  	//
  	template<typename T, bool ConvertibleToPointer = false>
  	class ptr_index_iterator
  		: public std::iterator<
  			typename std::iterator_traits<T*>::iterator_category,
  			typename std::iterator_traits<T*>::value_type,
  			typename std::iterator_traits<T*>::difference_type,
  			typename std::iterator_traits<T*>::pointer,
  			typename std::iterator_traits<T*>::reference
  		>
  		, public sprout::detail::iterator_to_pointer_base<
  			sprout::ptr_index_iterator<T, ConvertibleToPointer>,
  			typename std::iterator_traits<T*>::pointer,
  			ConvertibleToPointer
  		>
  	{
  	public:
  		typedef T type;
  	private:
  		typedef std::iterator<
  			typename std::iterator_traits<T*>::iterator_category,
  			typename std::iterator_traits<T*>::value_type,
  			typename std::iterator_traits<T*>::difference_type,
  			typename std::iterator_traits<T*>::pointer,
  			typename std::iterator_traits<T*>::reference
  		> base_type;
  	public:
  		typedef typename base_type::iterator_category iterator_category;
  		typedef typename base_type::value_type value_type;
  		typedef typename base_type::difference_type difference_type;
  		typedef typename base_type::pointer pointer;
  		typedef typename base_type::reference reference;
  		typedef typename std::remove_pointer<pointer>::type const* const_pointer;
  	private:
  		pointer p_;
  		difference_type index_;
  	public:
  		SPROUT_CONSTEXPR ptr_index_iterator()
  			: p_(), index_()
  		{}
  		ptr_index_iterator(ptr_index_iterator const&) = default;
  		explicit SPROUT_CONSTEXPR ptr_index_iterator(pointer p)
  			: p_(p), index_(0)
  		{}
  		SPROUT_CONSTEXPR ptr_index_iterator(pointer p, difference_type index)
  			: p_(p), index_(index)
  		{}
  		SPROUT_CONSTEXPR operator ptr_index_iterator<const_pointer>() const {
  			return ptr_index_iterator<const_pointer>(p_, index_);
  		}
  		SPROUT_CONSTEXPR pointer base() const {
  			return p_;
  		}
  		SPROUT_CONSTEXPR difference_type index() const {
  			return index_;
  		}
  		SPROUT_CONSTEXPR pointer ptr() const {
  			return p_ + index_;
  		}
  		SPROUT_CONSTEXPR ptr_index_iterator next() const {
  			return ptr_index_iterator(p_, index_ + 1);
  		}
  		SPROUT_CONSTEXPR ptr_index_iterator prev() const {
  			return ptr_index_iterator(p_, index_ - 1);
  		}
  		SPROUT_CXX14_CONSTEXPR void swap(ptr_index_iterator& other)
  		SPROUT_NOEXCEPT
  		{
  			sprout::swap(p_, other.p_);
  			sprout::swap(index_, other.index_);
  		}
  		SPROUT_CONSTEXPR reference operator*() const {
  			return p_[index_];
  		}
  		SPROUT_CONSTEXPR pointer operator->() const {
  			return p_ + index_;
  		}
  		SPROUT_CXX14_CONSTEXPR ptr_index_iterator& operator++() {
  			ptr_index_iterator temp(next());
  			temp.swap(*this);
  			return *this;
  		}
  		SPROUT_CXX14_CONSTEXPR ptr_index_iterator operator++(int) {
  			ptr_index_iterator result(*this);
  			++*this;
  			return result;
  		}
  		SPROUT_CXX14_CONSTEXPR ptr_index_iterator& operator--() {
  			ptr_index_iterator temp(prev());
  			temp.swap(*this);
  			return *this;
  		}
  		SPROUT_CXX14_CONSTEXPR ptr_index_iterator operator--(int) {
  			ptr_index_iterator result(*this);
  			--*this;
  			return result;
  		}
  		SPROUT_CONSTEXPR ptr_index_iterator operator+(difference_type n) const {
  			return ptr_index_iterator(p_, index_ + n);
  		}
  		SPROUT_CONSTEXPR ptr_index_iterator operator-(difference_type n) const {
  			return ptr_index_iterator(p_, index_ - n);
  		}
  		SPROUT_CXX14_CONSTEXPR ptr_index_iterator& operator+=(difference_type n) {
  			ptr_index_iterator temp(p_, index_ + n);
  			temp.swap(*this);
  			return *this;
  		}
  		SPROUT_CXX14_CONSTEXPR ptr_index_iterator& operator-=(difference_type n) {
  			ptr_index_iterator temp(p_, index_ - n);
  			temp.swap(*this);
  			return *this;
  		}
  		SPROUT_CONSTEXPR reference operator[](difference_type n) const {
  			return p_[index_ + n];
  		}
  	};
  
  	template<typename T1, typename T2, bool C>
  	inline SPROUT_CONSTEXPR typename std::enable_if<
  		std::is_same<typename std::decay<T1>::type, typename std::decay<T2>::type>::value,
  		bool
  	>::type
  	operator==(sprout::ptr_index_iterator<T1, C> const& lhs, sprout::ptr_index_iterator<T2, C> const& rhs) {
  		return lhs.index() == rhs.index();
  	}
  	template<typename T1, typename T2, bool C>
  	inline SPROUT_CONSTEXPR typename std::enable_if<
  		std::is_same<typename std::decay<T1>::type, typename std::decay<T2>::type>::value,
  		bool
  	>::type
  	operator!=(sprout::ptr_index_iterator<T1, C> const& lhs, sprout::ptr_index_iterator<T2, C> const& rhs) {
  		return !(lhs == rhs);
  	}
  	template<typename T1, typename T2, bool C>
  	inline SPROUT_CONSTEXPR typename std::enable_if<
  		std::is_same<typename std::decay<T1>::type, typename std::decay<T2>::type>::value,
  		bool
  	>::type
  	operator<(sprout::ptr_index_iterator<T1, C> const& lhs, sprout::ptr_index_iterator<T2, C> const& rhs) {
  		return lhs.index() < rhs.index();
  	}
  	template<typename T1, typename T2, bool C>
  	inline SPROUT_CONSTEXPR typename std::enable_if<
  		std::is_same<typename std::decay<T1>::type, typename std::decay<T2>::type>::value,
  		bool
  	>::type
  	operator>(sprout::ptr_index_iterator<T1, C> const& lhs, sprout::ptr_index_iterator<T2, C> const& rhs) {
  		return rhs < lhs;
  	}
  	template<typename T1, typename T2, bool C>
  	inline SPROUT_CONSTEXPR typename std::enable_if<
  		std::is_same<typename std::decay<T1>::type, typename std::decay<T2>::type>::value,
  		bool
  	>::type
  	operator<=(sprout::ptr_index_iterator<T1, C> const& lhs, sprout::ptr_index_iterator<T2, C> const& rhs) {
  		return !(rhs < lhs);
  	}
  	template<typename T1, typename T2, bool C>
  	inline SPROUT_CONSTEXPR typename std::enable_if<
  		std::is_same<typename std::decay<T1>::type, typename std::decay<T2>::type>::value,
  		bool
  	>::type
  	operator>=(sprout::ptr_index_iterator<T1, C> const& lhs, sprout::ptr_index_iterator<T2, C> const& rhs) {
  		return !(lhs < rhs);
  	}
  	template<typename T1, typename T2, bool C>
  	inline SPROUT_CONSTEXPR typename std::enable_if<
  		std::is_same<typename std::decay<T1>::type, typename std::decay<T2>::type>::value,
  		decltype(
  			std::declval<typename std::iterator_traits<sprout::ptr_index_iterator<T1, C> >::difference_type>()
  				- std::declval<typename std::iterator_traits<sprout::ptr_index_iterator<T2, C> >::difference_type>()
  			)
  	>::type
  	operator-(sprout::ptr_index_iterator<T1, C> const& lhs, sprout::ptr_index_iterator<T2, C> const& rhs) {
  		return lhs.index() - rhs.index();
  	}
  	template<typename T, bool C>
  	inline SPROUT_CONSTEXPR sprout::ptr_index_iterator<T, C>
  	operator+(typename sprout::ptr_index_iterator<T, C>::difference_type n, sprout::ptr_index_iterator<T, C> const& it) {
  		return it + n;
  	}
  
  	//
  	// swap
  	//
  	template<typename T>
  	inline SPROUT_CXX14_CONSTEXPR void
  	swap(sprout::ptr_index_iterator<T>& lhs, sprout::ptr_index_iterator<T>& rhs)
  	SPROUT_NOEXCEPT_IF_EXPR(lhs.swap(rhs))
  	{
  		lhs.swap(rhs);
  	}
  
  	//
  	// make_ptr_index_iterator
  	//
  	template<typename T>
  	inline SPROUT_CONSTEXPR sprout::ptr_index_iterator<T>
  	make_ptr_index_iterator(T* p) {
  		return sprout::ptr_index_iterator<T>(p);
  	}
  	template<typename T>
  	inline SPROUT_CONSTEXPR sprout::ptr_index_iterator<T>
  	make_ptr_index_iterator(T* p, typename sprout::ptr_index_iterator<T>::difference_type index) {
  		return sprout::ptr_index_iterator<T>(p, index);
  	}
  
  	//
  	// ptr_index
  	//
  	template<typename T>
  	inline SPROUT_CONSTEXPR sprout::ptr_index_iterator<T>
  	ptr_index(T* p) {
  		return sprout::make_ptr_index_iterator(p);
  	}
  	template<typename T>
  	inline SPROUT_CONSTEXPR sprout::ptr_index_iterator<T>
  	ptr_index(T* p, typename std::iterator_traits<T*>::difference_type n) {
  		return sprout::make_ptr_index_iterator(p, n);
  	}
  
  	template<typename Iterator>
  	inline SPROUT_CONSTEXPR Iterator
  	ptr_index(Iterator const& it) {
  		return it;
  	}
  	template<typename Iterator>
  	inline SPROUT_CONSTEXPR Iterator
  	ptr_index(Iterator const& it, typename std::iterator_traits<Iterator>::difference_type n) {
  		return sprout::next(it, n);
  	}
  
  	//
  	// ptr_unindex
  	//
  	template<typename T>
  	inline SPROUT_CONSTEXPR typename sprout::ptr_index_iterator<T>::pointer
  	ptr_unindex(sprout::ptr_index_iterator<T> const& it) {
  		return it.ptr();
  	}
  	template<typename Iterator>
  	inline SPROUT_CONSTEXPR Iterator
  	ptr_unindex(Iterator const& it) {
  		return it;
  	}
  
  	//
  	// is_ptr_index_iterator
  	//
  	template<typename T>
  	struct is_ptr_index_iterator
  		: public sprout::false_type
  	{};
  	template<typename T>
  	struct is_ptr_index_iterator<T const>
  		: public sprout::is_ptr_index_iterator<T>
  	{};
  	template<typename T>
  	struct is_ptr_index_iterator<T const volatile>
  		: public sprout::is_ptr_index_iterator<T>
  	{};
  	template<typename T>
  	struct is_ptr_index_iterator<sprout::ptr_index_iterator<T> >
  		: public sprout::true_type
  	{};
  
  	//
  	// iterator_next
  	//
  	template<typename T>
  	inline SPROUT_CONSTEXPR sprout::ptr_index_iterator<T>
  	iterator_next(sprout::ptr_index_iterator<T> const& it) {
  		return it.next();
  	}
  
  	//
  	// iterator_prev
  	//
  	template<typename T>
  	inline SPROUT_CONSTEXPR sprout::ptr_index_iterator<T>
  	iterator_prev(sprout::ptr_index_iterator<T> const& it) {
  		return it.prev();
  	}
  }	// namespace sprout
  
  #endif	// #ifndef SPROUT_ITERATOR_PTR_INDEX_ITERATOR_HPP
  