1 #ifndef INPUT_ITERATOR_H 2 #define INPUT_ITERATOR_H 3 4 #include <iterator> 5 6 template <class It> 7 class input_iterator 8 { 9 It it_; 10 public: 11 typedef typename std::input_iterator_tag iterator_category; 12 typedef typename std::iterator_traits<It>::value_type value_type; 13 typedef typename std::iterator_traits<It>::difference_type difference_type; 14 typedef It pointer; 15 typedef typename std::iterator_traits<It>::reference reference; 16 17 input_iterator() : it_() {} 18 explicit input_iterator(It it) : it_(it) {} 19 20 reference operator*() const {return *it_;} 21 pointer operator->() const {return it_;} 22 23 input_iterator& operator++() {++it_; return *this;} 24 input_iterator operator++(int) {input_iterator tmp(*this); ++(*this); return tmp;} 25 26 friend bool operator==(const input_iterator& x, const input_iterator& y) 27 {return x.it_ == y.it_;} 28 friend bool operator!=(const input_iterator& x, const input_iterator& y) 29 {return !(x == y);} 30 }; 31 32 #endif // INPUT_ITERATOR_H 33
