iterator.hpp 追加

utility.hpp 追加

sprout/iterator/reverse_iterator.hpp

@@ -0,0 +1,184 @@
+#ifndef SPROUT_ITERATOR_REVERSE_ITERATOR_HPP
+#define SPROUT_ITERATOR_REVERSE_ITERATOR_HPP
+
+#include <iterator>
+#include <utility>
+#include <sprout/config.hpp>
+#include <sprout/iterator/next.hpp>
+#include <sprout/iterator/prev.hpp>
+
+namespace sprout {
+	//
+	// reverse_iterator
+	//
+	template<typename Iterator>
+	class reverse_iterator
+		: public std::iterator<
+			typename std::iterator_traits<Iterator>::iterator_category,
+			typename std::iterator_traits<Iterator>::value_type,
+			typename std::iterator_traits<Iterator>::difference_type,
+			typename std::iterator_traits<Iterator>::pointer,
+			typename std::iterator_traits<Iterator>::reference
+		>
+	{
+	public:
+		typedef Iterator iterator_type;
+		typedef typename std::iterator_traits<iterator_type>::iterator_category iterator_category;
+		typedef typename std::iterator_traits<iterator_type>::value_type value_type;
+		typedef typename std::iterator_traits<iterator_type>::difference_type difference_type;
+		typedef typename std::iterator_traits<iterator_type>::pointer pointer;
+		typedef typename std::iterator_traits<iterator_type>::reference reference;
+	protected:
+		iterator_type current;
+	private:
+		iterator_type deref_tmp;
+	public:
+		reverse_iterator() = default;
+		reverse_iterator(reverse_iterator const&) = default;
+		SPROUT_CONSTEXPR explicit reverse_iterator(iterator_type it)
+			: current(it)
+			, deref_tmp(sprout::prev(it))
+		{}
+		template<typename U>
+		SPROUT_CONSTEXPR reverse_iterator(reverse_iterator<U> const& it)
+			: current(it)
+			, deref_tmp(sprout::prev(it))
+		{}
+		template<typename U>
+		reverse_iterator& operator=(reverse_iterator<U> const& it) {
+			reverse_iterator temp(it);
+			temp.swap(this);
+			return this;
+		}
+		SPROUT_CONSTEXPR iterator_type base() const {
+			return current;
+		}
+		SPROUT_CONSTEXPR reference operator*() const {
+			return *deref_tmp;
+		}
+		SPROUT_CONSTEXPR pointer operator->() const {
+			return &*deref_tmp;
+		}
+		reverse_iterator& operator++() {
+			--current;
+			--deref_tmp;
+			return this;
+		}
+		reverse_iterator operator++(int) {
+			reverse_iterator result(this);
+			--current;
+			--deref_tmp;
+			return result;
+		}
+		reverse_iterator& operator--() {
+			++current;
+			++deref_tmp;
+			return this;
+		}
+		reverse_iterator operator--(int) {
+			reverse_iterator temp(this);
+			++current;
+			++deref_tmp;
+			return temp;
+		}
+		SPROUT_CONSTEXPR reverse_iterator operator+(difference_type n) const {
+			return reverse_iterator(current - n);
+		}
+		SPROUT_CONSTEXPR reverse_iterator operator-(difference_type n) const {
+			return reverse_iterator(current + n);
+		}
+		reverse_iterator& operator+=(difference_type n) {
+			reverse_iterator temp(current - n);
+			temp.swap(this);
+			return this;
+		}
+		reverse_iterator& operator-=(difference_type n) {
+			reverse_iterator temp(current + n);
+			temp.swap(this);
+			return this;
+		}
+		SPROUT_CONSTEXPR reference operator[](difference_type n) const {
+			return *(deref_tmp - n);
+		}
+		void swap(reverse_iterator& other) {
+			using std::swap;
+			swap(current, other.current);
+			swap(deref_tmp, other.deref_tmp);
+		}
+	};
+	template <typename Iterator1, typename Iterator2>
+	SPROUT_CONSTEXPR bool operator==(
+		sprout::reverse_iterator<Iterator1> const& lhs,
+		sprout::reverse_iterator<Iterator2> const& rhs
+		)
+	{
+		return lhs.base() == rhs.base();
+	}
+	template <typename Iterator1, typename Iterator2>
+	SPROUT_CONSTEXPR bool operator!=(
+		sprout::reverse_iterator<Iterator1> const& lhs,
+		sprout::reverse_iterator<Iterator2> const& rhs
+		)
+	{
+		return !(lhs == rhs);
+	}
+	template <typename Iterator1, typename Iterator2>
+	bool operator<(
+		sprout::reverse_iterator<Iterator1> const& lhs,
+		sprout::reverse_iterator<Iterator2> const& rhs
+		)
+	{
+		return lhs.base() < rhs.base();
+	}
+	template <typename Iterator1, typename Iterator2>
+	bool operator>(
+		sprout::reverse_iterator<Iterator1> const& lhs,
+		sprout::reverse_iterator<Iterator2> const& rhs
+		)
+	{
+		return rhs < lhs;
+	}
+	template <typename Iterator1, typename Iterator2>
+	bool operator<=(
+		sprout::reverse_iterator<Iterator1> const& lhs,
+		sprout::reverse_iterator<Iterator2> const& rhs
+		)
+	{
+		return !(rhs < lhs);
+	}
+	template <typename Iterator1, typename Iterator2>
+	bool operator>=(
+		sprout::reverse_iterator<Iterator1> const& lhs,
+		sprout::reverse_iterator<Iterator2> const& rhs
+		)
+	{
+		return !(lhs < rhs);
+	}
+	template <typename Iterator1, typename Iterator2>
+	auto operator-(
+		sprout::reverse_iterator<Iterator1> const& lhs,
+		sprout::reverse_iterator<Iterator2> const& rhs
+		) -> decltype(lhs.current - rhs.current)
+	{
+		return lhs.current - rhs.current;
+	}
+	template <typename Iterator>
+	SPROUT_CONSTEXPR sprout::reverse_iterator<Iterator> operator+(
+		typename sprout::reverse_iterator<Iterator>::difference_type n,
+		sprout::reverse_iterator<Iterator> const& it
+		)
+	{
+		return it + n;
+	}
+
+	//
+	// swap
+	//
+	template<typename Iterator>
+	void swap(sprout::reverse_iterator<Iterator>& lhs, sprout::reverse_iterator<Iterator>& rhs) SPROUT_NOEXCEPT_EXPR(SPROUT_NOEXCEPT_EXPR(lhs.swap(rhs))) {
+		lhs.swap(rhs);
+	}
+}	// namespace sprout
+
+#endif	// #ifndef SPROUT_ITERATOR_REVERSE_ITERATOR_HPP
+