1#ifndef _DATE_TIME_ADJUST_FUNCTORS_HPP___
2#define _DATE_TIME_ADJUST_FUNCTORS_HPP___
3
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
9 * $Date$
10 */
11
12#include "boost/date_time/date.hpp"
13#include "boost/date_time/wrapping_int.hpp"
14
15namespace boost {
16namespace date_time {
17
18
19 //! Functor to iterate a fixed number of days
20 template<class date_type>
21 class day_functor
22 {
23 public:
24 typedef typename date_type::duration_type duration_type;
25 day_functor(int f) : f_(f) {}
26 duration_type get_offset(const date_type& d) const
27 {
28 // why is 'd' a parameter???
29 // fix compiler warnings
30 d.year();
31 return duration_type(f_);
32 }
33 duration_type get_neg_offset(const date_type& d) const
34 {
35 // fix compiler warnings
36 d.year();
37 return duration_type(-f_);
38 }
39 private:
40 int f_;
41 };
42
43
44 //! Provides calculation to find next nth month given a date
45 /*! This adjustment function provides the logic for 'month-based'
46 * advancement on a ymd based calendar. The policy it uses
47 * to handle the non existant end of month days is to back
48 * up to the last day of the month. Also, if the starting
49 * date is the last day of a month, this functor will attempt
50 * to adjust to the end of the month.
51
52 */
53 template<class date_type>
54 class month_functor
55 {
56 public:
57 typedef typename date_type::duration_type duration_type;
58 typedef typename date_type::calendar_type cal_type;
59 typedef typename cal_type::ymd_type ymd_type;
60 typedef typename cal_type::day_type day_type;
61
62 month_functor(int f) : f_(f), origDayOfMonth_(0) {}
63 duration_type get_offset(const date_type& d) const
64 {
65 ymd_type ymd(d.year_month_day());
66 if (origDayOfMonth_ == 0) {
67 origDayOfMonth_ = ymd.day;
68 day_type endOfMonthDay(cal_type::end_of_month_day(ymd.year,ymd.month));
69 if (endOfMonthDay == ymd.day) {
70 origDayOfMonth_ = -1; //force the value to the end of month
71 }
72 }
73 typedef date_time::wrapping_int2<short,1,12> wrap_int2;
74 typedef typename wrap_int2::int_type int_type;
75 wrap_int2 wi(ymd.month);
76 //calc the year wrap around, add() returns 0 or 1 if wrapped
77 int_type year = wi.add(v: static_cast<int_type>(f_));
78 year = static_cast<int_type>(year + ymd.year); //calculate resulting year
79// std::cout << "trace wi: " << wi.as_int() << std::endl;
80// std::cout << "trace year: " << year << std::endl;
81 //find the last day for the new month
82 day_type resultingEndOfMonthDay(cal_type::end_of_month_day(year, wi.as_int()));
83 //original was the end of month -- force to last day of month
84 if (origDayOfMonth_ == -1) {
85 return date_type(year, wi.as_int(), resultingEndOfMonthDay) - d;
86 }
87 day_type dayOfMonth = origDayOfMonth_;
88 if (dayOfMonth > resultingEndOfMonthDay) {
89 dayOfMonth = resultingEndOfMonthDay;
90 }
91 return date_type(year, wi.as_int(), dayOfMonth) - d;
92 }
93 //! Returns a negative duration_type
94 duration_type get_neg_offset(const date_type& d) const
95 {
96 ymd_type ymd(d.year_month_day());
97 if (origDayOfMonth_ == 0) {
98 origDayOfMonth_ = ymd.day;
99 day_type endOfMonthDay(cal_type::end_of_month_day(ymd.year,ymd.month));
100 if (endOfMonthDay == ymd.day) {
101 origDayOfMonth_ = -1; //force the value to the end of month
102 }
103 }
104 typedef date_time::wrapping_int2<short,1,12> wrap_int2;
105 typedef typename wrap_int2::int_type int_type;
106 wrap_int2 wi(ymd.month);
107 //calc the year wrap around, add() returns 0 or 1 if wrapped
108 int_type year = wi.subtract(v: static_cast<int_type>(f_));
109 year = static_cast<int_type>(year + ymd.year); //calculate resulting year
110 //find the last day for the new month
111 day_type resultingEndOfMonthDay(cal_type::end_of_month_day(year, wi.as_int()));
112 //original was the end of month -- force to last day of month
113 if (origDayOfMonth_ == -1) {
114 return date_type(year, wi.as_int(), resultingEndOfMonthDay) - d;
115 }
116 day_type dayOfMonth = origDayOfMonth_;
117 if (dayOfMonth > resultingEndOfMonthDay) {
118 dayOfMonth = resultingEndOfMonthDay;
119 }
120 return date_type(year, wi.as_int(), dayOfMonth) - d;
121 }
122 private:
123 int f_;
124 mutable short origDayOfMonth_;
125 };
126
127
128 //! Functor to iterate a over weeks
129 template<class date_type>
130 class week_functor
131 {
132 public:
133 typedef typename date_type::duration_type duration_type;
134 typedef typename date_type::calendar_type calendar_type;
135 week_functor(int f) : f_(f) {}
136 duration_type get_offset(const date_type& d) const
137 {
138 // why is 'd' a parameter???
139 // fix compiler warnings
140 d.year();
141 return duration_type(f_*calendar_type::days_in_week());
142 }
143 duration_type get_neg_offset(const date_type& d) const
144 {
145 // fix compiler warnings
146 d.year();
147 return duration_type(-f_*calendar_type::days_in_week());
148 }
149 private:
150 int f_;
151 };
152
153 //! Functor to iterate by a year adjusting for leap years
154 template<class date_type>
155 class year_functor
156 {
157 public:
158 //typedef typename date_type::year_type year_type;
159 typedef typename date_type::duration_type duration_type;
160 year_functor(int f) : _mf(f * 12) {}
161 duration_type get_offset(const date_type& d) const
162 {
163 return _mf.get_offset(d);
164 }
165 duration_type get_neg_offset(const date_type& d) const
166 {
167 return _mf.get_neg_offset(d);
168 }
169 private:
170 month_functor<date_type> _mf;
171 };
172
173
174} }//namespace date_time
175
176
177#endif
178
179

source code of boost/boost/date_time/adjust_functors.hpp