iterator_base

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/*	Copyright (C) 2004 Garrett A. Kajmowicz

	This file is part of the uClibc++ Library.

	This library is free software; you can redistribute it and/or
	modify it under the terms of the GNU Lesser General Public
	License as published by the Free Software Foundation; either
	version 2.1 of the License, or (at your option) any later version.

	This library is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
	Lesser General Public License for more details.

	You should have received a copy of the GNU Lesser General Public
	License along with this library; if not, write to the Free Software
	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#include "basic_definitions"

#ifndef __STD_HEADER_ITERATOR_BASE
#define __STD_HEADER_ITERATOR_BASE 1


namespace std{
	template<class Iterator> struct iterator_traits;
	template<class T> struct iterator_traits<T*>;

	template<class Category, class T, class Distance = ptrdiff_t, class Pointer = T*, class Reference = T&> struct iterator;

	struct _UCXXEXPORT input_iterator_tag {};
	struct _UCXXEXPORT output_iterator_tag {};
	struct _UCXXEXPORT forward_iterator_tag: public input_iterator_tag {};
	struct _UCXXEXPORT bidirectional_iterator_tag: public forward_iterator_tag {};
	struct _UCXXEXPORT random_access_iterator_tag: public bidirectional_iterator_tag {};

	template <class InputIterator, class Distance> _UCXXEXPORT void advance(InputIterator& i, Distance n){
		while(n > 0){
			--n;
			++i;
		}
	}

	template <class InputIterator> _UCXXEXPORT typename iterator_traits<InputIterator>::difference_type 
		distance(InputIterator first, InputIterator last)
	{
		typename iterator_traits<InputIterator>::difference_type d = 0;
		while(first++ !=last){
			d++;
		}
		return d;
	}

  // subclause _lib.predef.iterators_, predefined iterators:
	template <class Iterator> class reverse_iterator;
	template <class Iterator> bool operator==(const reverse_iterator<Iterator>& x, const reverse_iterator<Iterator>& y);
	template <class Iterator> bool operator<(const reverse_iterator<Iterator>& x, const reverse_iterator<Iterator>& y);
	template <class Iterator> bool operator!=(const reverse_iterator<Iterator>& x, const reverse_iterator<Iterator>& y);
	template <class Iterator> bool operator>(const reverse_iterator<Iterator>& x, const reverse_iterator<Iterator>& y);
	template <class Iterator> bool operator>=(const reverse_iterator<Iterator>& x, const reverse_iterator<Iterator>& y);
	template <class Iterator> bool operator<=(const reverse_iterator<Iterator>& x, const reverse_iterator<Iterator>& y);
	template <class Iterator> typename reverse_iterator<Iterator>::difference_type
		operator-( const reverse_iterator<Iterator>& x, const reverse_iterator<Iterator>& y);
	template <class Iterator> reverse_iterator<Iterator> 
		operator+( typename reverse_iterator<Iterator>::difference_type n, const reverse_iterator<Iterator>& x);
	template <class Container> class back_insert_iterator;
	template <class Container> back_insert_iterator<Container> back_inserter(Container& x);
	template <class Container> class front_insert_iterator;
	template <class Container> front_insert_iterator<Container> front_inserter(Container& x);
	template <class Container> class insert_iterator;
	template <class Container, class Iterator>
		insert_iterator<Container> inserter(Container& x, Iterator i);
	
	//Actual Template definitions

	template<class Iterator> struct _UCXXEXPORT iterator_traits {
		typedef typename Iterator::difference_type difference_type;
		typedef typename Iterator::value_type value_type;
		typedef typename Iterator::pointer pointer;
		typedef typename Iterator::reference reference;
		typedef typename Iterator::iterator_category iterator_category;
	};

	//Pointer specialization - required by standard
	template<class T> struct _UCXXEXPORT iterator_traits<T*> {
		typedef ptrdiff_t difference_type;
		typedef T value_type;
		typedef T* pointer;
		typedef T& reference;
		typedef random_access_iterator_tag iterator_category;
	};

	//Specialization recomended by standard
/*	template<class T> struct _UCXXEXPORT iterator_traits<T __far*> {
		typedef long difference_type;
		typedef T value_type;
		typedef T __far* pointer;
		typedef T __far& reference;
		typedef random_access_iterator_tag iterator_category;
	};*/

/*	template <class BidirectionalIterator> _UCXXEXPORT void
		reverse(BidirectionalIterator first, BidirectionalIterator last)
	{
		typename iterator_traits<BidirectionalIterator>::difference_type n = distance(first, last);
		--n;
		while(n > 0){
			typename iterator_traits<BidirectionalIterator>::value_type tmp = *first;
			*first++ = * --last;
			*last = tmp;
			n -= 2;
		}
	};*/


	template <class Category, class T, class Distance, class Pointer, class Reference> 
		struct _UCXXEXPORT iterator
	{
		typedef T         value_type;
		typedef Distance  difference_type;
		typedef Pointer   pointer;
		typedef Reference reference;
		typedef Category  iterator_category;
	};


	template <class Iterator> class _UCXXEXPORT reverse_iterator
		: public iterator<typename iterator_traits<Iterator>::iterator_category,
		typename iterator_traits<Iterator>::value_type, typename iterator_traits<Iterator>::difference_type,
		typename iterator_traits<Iterator>::pointer, typename iterator_traits<Iterator>::reference>
	{
	protected:
		Iterator current;
		friend bool operator== <Iterator>(const reverse_iterator<Iterator>& x, const reverse_iterator<Iterator>& y);
		friend bool operator< <Iterator>(const reverse_iterator<Iterator>& x, const reverse_iterator<Iterator>& y);

	public:
		typedef Iterator iterator_type;

		reverse_iterator() : current(){};
		explicit reverse_iterator(Iterator x) : current(x) { }
		template<class U> reverse_iterator(const reverse_iterator<U> &x) : current(x.base()){}

		Iterator base() const { return current; }        // explicit

		typename iterator_traits<Iterator>::reference operator*() const { Iterator tmp = current; return *--tmp; }
		typename iterator_traits<Iterator>::pointer   operator->() const { return &(operator*()); }
		typename iterator_traits<Iterator>::reference operator[](typename iterator_traits<Iterator>::difference_type n) const{
			return current[-n-1];
		}

		reverse_iterator& operator++(){ --current; return *this;	}
		reverse_iterator  operator++(int) {reverse_iterator tmp = *this; --current; return tmp; }
		reverse_iterator& operator--() { ++ current; return *this; }
		reverse_iterator  operator--(int) {reverse_iterator tmp = *this; ++current; return tmp; }

		reverse_iterator  operator+ (typename iterator_traits<Iterator>::difference_type n) const{
			reverse_iterator retval( *this );
			retval+=n;
			return retval;
		}
		reverse_iterator& operator+=(typename iterator_traits<Iterator>::difference_type n){
			current -= n;
			return *this;
		}
		reverse_iterator operator- (typename iterator_traits<Iterator>::difference_type n) const{
			reverse_iterator retval( *this );
			retval-=n;
			return retval;
		}
		reverse_iterator& operator-=(typename iterator_traits<Iterator>::difference_type n){
			current += n;
			return *this;
		}
	 };


	template <class Iterator> _UCXXEXPORT bool
		operator==(const reverse_iterator<Iterator>& x, const reverse_iterator<Iterator>& y)
	{
		return x.base() == y.base();
	}
	template <class Iterator> _UCXXEXPORT bool
		operator<(const reverse_iterator<Iterator>& x, const reverse_iterator<Iterator>& y)
	{
		return x.base() < y.base();
	}
	template <class Iterator> _UCXXEXPORT bool
		operator!=(const reverse_iterator<Iterator>& x, const reverse_iterator<Iterator>& y)
	{
		return x.base() != y.base();
	}
	template <class Iterator> _UCXXEXPORT bool
		operator>(const reverse_iterator<Iterator>& x, const reverse_iterator<Iterator>& y)
	{
		return x.base() > y.base();
	}
	template <class Iterator> _UCXXEXPORT bool
		operator>=(const reverse_iterator<Iterator>& x, const reverse_iterator<Iterator>& y)
	{
		return x.base() >= y.base();
	}
	template <class Iterator> _UCXXEXPORT bool
		operator<=(const reverse_iterator<Iterator>& x, const reverse_iterator<Iterator>& y)
	{
		return x.base() <= y.base();
	}
	template <class Iterator> _UCXXEXPORT typename reverse_iterator<Iterator>::difference_type
		operator-( const reverse_iterator<Iterator>& x, const reverse_iterator<Iterator>& y)
	{
		return y.base() - x.base();
	}
	template <class Iterator> _UCXXEXPORT reverse_iterator<Iterator>
		operator+(typename reverse_iterator<Iterator>::difference_type n, const reverse_iterator<Iterator>& x)
	{
		return reverse_iterator<Iterator> (x.base() - n);
	}

	template <class Container> class _UCXXEXPORT back_insert_iterator : 
		public iterator<output_iterator_tag,void,void,void,void>
	{
	protected:
		Container& container;
	public:
		typedef Container container_type;
		explicit back_insert_iterator(Container& x):container(x) {};
		back_insert_iterator<Container>& operator=(const typename Container::value_type& value){
			container.push_back(value);
			return *this;
		}
		back_insert_iterator<Container>& operator*(){
			return *this;
		}
		back_insert_iterator<Container>& operator++(){
			return *this;
		}
		back_insert_iterator<Container>  operator++(int){
			return *this;
		}
	};

	template <class Container> _UCXXEXPORT back_insert_iterator<Container>
		back_inserter(Container& x)
	{
		return back_insert_iterator<Container>(x);
	}

	template <class Container> class _UCXXEXPORT front_insert_iterator
		: public iterator<output_iterator_tag,void,void,void,void>
	{
	protected:
		Container& container;
	public:
		typedef Container container_type;
		explicit front_insert_iterator(Container& x): container(x) {}
		front_insert_iterator<Container>& operator=(const typename Container::value_type& value){
			container.push_front(value);
			return *this;
		}

		front_insert_iterator<Container>& operator*() { return *this; }
		front_insert_iterator<Container>& operator++() { return *this; }
		front_insert_iterator<Container> operator++(int) { return *this; }
	};

	template <class Container> _UCXXEXPORT front_insert_iterator<Container>
		front_inserter(Container& x)
	{
		return front_insert_iterator<Container>(x);
	}

	template <class Container> class _UCXXEXPORT insert_iterator
		: public iterator<output_iterator_tag,void,void,void,void>
	{
	protected:
		Container& container;
		typename Container::iterator iter;
	public:
		typedef Container container_type;
		insert_iterator(Container& x, typename Container::iterator i) : container(x), iter(i) {}
		insert_iterator<Container>& operator=(const typename Container::value_type& value){
			iter = container.insert(iter, value);
			++iter;
			return *this;
		}
		insert_iterator<Container>& operator*() { return *this; } 
		insert_iterator<Container>& operator++() { return *this; }
		insert_iterator<Container> operator++(int) { return *this; }
	};

	template <class Container, class Iterator> _UCXXEXPORT insert_iterator<Container>
		inserter(Container& x, Iterator i)
	{
		return insert_iterator<Container>(x,typename Container::iterator(i));
	}

}


#endif