1 #ifndef DATE_ITERATOR_HPP___
2 #define DATE_ITERATOR_HPP___
4 /* Copyright (c) 2002,2003 CrystalClear Software, Inc.
5 * Use, modification and distribution is subject to the
6 * Boost Software License, Version 1.0. (See accompanying
7 * file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
8 * Author: Jeff Garland, Bart Garst
16 //! An iterator over dates with varying resolution (day, week, month, year, etc)
17 enum date_resolutions {day, week, months, year, decade, century, NumDateResolutions};
19 //! Base date iterator type
20 /*! This class provides the skeleton for the creation of iterators.
21 * New and interesting interators can be created by plugging in a new
22 * function that derives the next value from the current state.
23 * generation of various types of -based information.
25 * <b>Template Parameters</b>
29 * The date_type is a concrete date_type. The date_type must
30 * define a duration_type and a calendar_type.
32 template<class date_type>
34 // works, but benefit unclear at the moment
35 // class date_itr_base : public std::iterator<std::input_iterator_tag,
36 // date_type, void, void, void>{
38 typedef typename date_type::duration_type duration_type;
39 typedef date_type value_type;
40 typedef std::input_iterator_tag iterator_category;
42 date_itr_base(date_type d) : current_(d) {}
43 virtual ~date_itr_base() {}
44 date_itr_base& operator++()
46 current_ = current_ + get_offset(current_);
49 date_itr_base& operator--()
51 current_ = current_ + get_neg_offset(current_);
54 virtual duration_type get_offset(const date_type& current) const=0;
55 virtual duration_type get_neg_offset(const date_type& current) const=0;
56 date_type operator*() {return current_;}
57 date_type* operator->() {return ¤t_;}
58 bool operator< (const date_type& d) {return current_ < d;}
59 bool operator<= (const date_type& d) {return current_ <= d;}
60 bool operator> (const date_type& d) {return current_ > d;}
61 bool operator>= (const date_type& d) {return current_ >= d;}
62 bool operator== (const date_type& d) {return current_ == d;}
63 bool operator!= (const date_type& d) {return current_ != d;}
68 //! Overrides the base date iterator providing hook for functors
70 * <b>offset_functor</b>
72 * The offset functor must define a get_offset function that takes the
73 * current point in time and calculates and offset.
76 template<class offset_functor, class date_type>
77 class date_itr : public date_itr_base<date_type> {
79 typedef typename date_type::duration_type duration_type;
80 date_itr(date_type d, int factor=1) :
81 date_itr_base<date_type>(d),
85 virtual duration_type get_offset(const date_type& current) const
87 return of_.get_offset(current);
89 virtual duration_type get_neg_offset(const date_type& current) const
91 return of_.get_neg_offset(current);
98 } } //namespace date_time