blob: 7b0f63384de77d60f303f83b09b49a8aeac5d658 [file] [log] [blame]
#ifndef ITERATORS_H
#define ITERATORS_H
#include <iterator>
template <class It>
class input_iterator
{
It it_;
template <class U> friend class input_iterator;
public:
typedef std::input_iterator_tag iterator_category;
typedef typename std::iterator_traits<It>::value_type value_type;
typedef typename std::iterator_traits<It>::difference_type difference_type;
typedef It pointer;
typedef typename std::iterator_traits<It>::reference reference;
It base() const {return it_;}
input_iterator() : it_() {}
explicit input_iterator(It it) : it_(it) {}
template <class U>
input_iterator(const input_iterator<U>& u) :it_(u.it_) {}
reference operator*() const {return *it_;}
pointer operator->() const {return it_;}
input_iterator& operator++() {++it_; return *this;}
input_iterator operator++(int)
{input_iterator tmp(*this); ++(*this); return tmp;}
friend bool operator==(const input_iterator& x, const input_iterator& y)
{return x.it_ == y.it_;}
friend bool operator!=(const input_iterator& x, const input_iterator& y)
{return !(x == y);}
};
template <class T, class U>
inline
bool
operator==(const input_iterator<T>& x, const input_iterator<U>& y)
{
return x.base() == y.base();
}
template <class T, class U>
inline
bool
operator!=(const input_iterator<T>& x, const input_iterator<U>& y)
{
return !(x == y);
}
#endif // ITERATORS_H