1 #ifndef DATE_TIME_DATE_GENERATORS_HPP__
2 #define DATE_TIME_DATE_GENERATORS_HPP__
4 /* Copyright (c) 2002,2003,2005 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
12 /*! @file date_generators.hpp
13 Definition and implementation of date algorithm templates
18 #include <boost/throw_exception.hpp>
19 #include <boost/date_time/date.hpp>
20 #include <boost/date_time/compiler_config.hpp>
25 //! Base class for all generators that take a year and produce a date.
26 /*! This class is a base class for polymorphic function objects that take
27 a year and produce a concrete date.
28 @param date_type The type representing a date. This type must
29 export a calender_type which defines a year_type.
31 template<class date_type>
32 class year_based_generator
35 typedef typename date_type::calendar_type calendar_type;
36 typedef typename calendar_type::year_type year_type;
37 year_based_generator() {}
38 virtual ~year_based_generator() {}
39 virtual date_type get_date(year_type y) const = 0;
40 //! Returns a string for use in a POSIX time_zone string
41 virtual std::string to_string() const =0;
44 //! Generates a date by applying the year to the given month and day.
48 partial_date pd(1, Jan);
50 date d = pd.get_date(2002); //2002-Jan-01
51 date d2 = pd2.get_date(2002); //2002-Mar-10
55 template<class date_type>
56 class partial_date : public year_based_generator<date_type>
59 typedef typename date_type::calendar_type calendar_type;
60 typedef typename calendar_type::day_type day_type;
61 typedef typename calendar_type::month_type month_type;
62 typedef typename calendar_type::year_type year_type;
63 typedef typename date_type::duration_type duration_type;
64 typedef typename duration_type::duration_rep duration_rep;
65 partial_date(day_type d, month_type m) :
69 //! Partial date created from number of days into year. Range 1-366
70 /*! Allowable values range from 1 to 366. 1=Jan1, 366=Dec31. If argument
71 * exceeds range, partial_date will be created with closest in-range value.
72 * 60 will always be Feb29, if get_date() is called with a non-leap year
73 * an exception will be thrown */
74 partial_date(duration_rep days) :
75 day_(1), // default values
78 date_type d1(2000,1,1);
80 if(days > 366) // prevents wrapping
85 duration_type dd(days);
91 //! Return a concrete date when provided with a year specific year.
92 /*! Will throw an 'invalid_argument' exception if a partial_date object,
93 * instantiated with Feb-29, has get_date called with a non-leap year.
96 * partial_date pd(29, Feb);
97 * pd.get_date(2003); // throws invalid_argument exception
98 * pg.get_date(2000); // returns 2000-2-29
101 date_type get_date(year_type y) const
103 if((day_ == 29) && (month_ == 2) && !(calendar_type::is_leap_year(y))) {
104 std::ostringstream ss;
105 ss << "No Feb 29th in given year of " << y << ".";
106 boost::throw_exception(std::invalid_argument(ss.str()));
108 return date_type(y, month_, day_);
110 date_type operator()(year_type y) const
113 //return date_type(y, month_, day_);
115 bool operator==(const partial_date& rhs) const
117 return (month_ == rhs.month_) && (day_ == rhs.day_);
119 bool operator<(const partial_date& rhs) const
121 if (month_ < rhs.month_) return true;
122 if (month_ > rhs.month_) return false;
124 return (day_ < rhs.day_);
127 // added for streaming purposes
128 month_type month() const
137 //! Returns string suitable for use in POSIX time zone string
138 /*! Returns string formatted with up to 3 digits:
142 virtual std::string to_string() const
144 std::ostringstream ss;
145 date_type d(2004, month_, day_);
146 unsigned short c = d.day_of_year();
147 c--; // numbered 0-365 while day_of_year is 1 based...
157 //! Returns nth arg as string. 1 -> "first", 2 -> "second", max is 5.
158 BOOST_DATE_TIME_DECL const char* nth_as_str(int n);
160 //! Useful generator functor for finding holidays
161 /*! Based on the idea in Cal. Calc. for finding holidays that are
162 * the 'first Monday of September'. When instantiated with
163 * 'fifth' kday of month, the result will be the last kday of month
164 * which can be the fourth or fifth depending on the structure of
167 * The algorithm here basically guesses for the first
168 * day of the month. Then finds the first day of the correct
169 * type. That is, if the first of the month is a Tuesday
170 * and it needs Wenesday then we simply increment by a day
171 * and then we can add the length of a week until we get
172 * to the 'nth kday'. There are probably more efficient
173 * algorithms based on using a mod 7, but this one works
174 * reasonably well for basic applications.
177 template<class date_type>
178 class nth_kday_of_month : public year_based_generator<date_type>
181 typedef typename date_type::calendar_type calendar_type;
182 typedef typename calendar_type::day_of_week_type day_of_week_type;
183 typedef typename calendar_type::month_type month_type;
184 typedef typename calendar_type::year_type year_type;
185 typedef typename date_type::duration_type duration_type;
186 enum week_num {first=1, second, third, fourth, fifth};
187 nth_kday_of_month(week_num week_no,
188 day_of_week_type dow,
194 //! Return a concrete date when provided with a year specific year.
195 date_type get_date(year_type y) const
197 date_type d(y, month_, 1); //first day of month
198 duration_type one_day(1);
199 duration_type one_week(7);
200 while (dow_ != d.day_of_week()) {
208 // remove wrapping to next month behavior
209 if(d.month() != month_) {
214 // added for streaming
215 month_type month() const
219 week_num nth_week() const
223 day_of_week_type day_of_week() const
227 const char* nth_week_as_str() const
229 return nth_as_str(wn_);
231 //! Returns string suitable for use in POSIX time zone string
232 /*! Returns a string formatted as "M4.3.0" ==> 3rd Sunday in April. */
233 virtual std::string to_string() const
235 std::ostringstream ss;
237 << static_cast<int>(month_) << '.'
238 << static_cast<int>(wn_) << '.'
239 << static_cast<int>(dow_);
245 day_of_week_type dow_;
248 //! Useful generator functor for finding holidays and daylight savings
249 /*! Similar to nth_kday_of_month, but requires less paramters
252 template<class date_type>
253 class first_kday_of_month : public year_based_generator<date_type>
256 typedef typename date_type::calendar_type calendar_type;
257 typedef typename calendar_type::day_of_week_type day_of_week_type;
258 typedef typename calendar_type::month_type month_type;
259 typedef typename calendar_type::year_type year_type;
260 typedef typename date_type::duration_type duration_type;
261 //!Specify the first 'Sunday' in 'April' spec
262 /*!@param dow The day of week, eg: Sunday, Monday, etc
263 * @param m The month of the year, eg: Jan, Feb, Mar, etc
265 first_kday_of_month(day_of_week_type dow, month_type m) :
269 //! Return a concrete date when provided with a year specific year.
270 date_type get_date(year_type year) const
272 date_type d(year, month_,1);
273 duration_type one_day(1);
274 while (dow_ != d.day_of_week()) {
279 // added for streaming
280 month_type month() const
284 day_of_week_type day_of_week() const
288 //! Returns string suitable for use in POSIX time zone string
289 /*! Returns a string formatted as "M4.1.0" ==> 1st Sunday in April. */
290 virtual std::string to_string() const
292 std::ostringstream ss;
294 << static_cast<int>(month_) << '.'
296 << static_cast<int>(dow_);
301 day_of_week_type dow_;
306 //! Calculate something like Last Sunday of January
307 /*! Useful generator functor for finding holidays and daylight savings
308 * Get the last day of the month and then calculate the difference
309 * to the last previous day.
310 * @param date_type A date class that exports day_of_week, month_type, etc.
313 template<class date_type>
314 class last_kday_of_month : public year_based_generator<date_type>
317 typedef typename date_type::calendar_type calendar_type;
318 typedef typename calendar_type::day_of_week_type day_of_week_type;
319 typedef typename calendar_type::month_type month_type;
320 typedef typename calendar_type::year_type year_type;
321 typedef typename date_type::duration_type duration_type;
322 //!Specify the date spec like last 'Sunday' in 'April' spec
323 /*!@param dow The day of week, eg: Sunday, Monday, etc
324 * @param m The month of the year, eg: Jan, Feb, Mar, etc
326 last_kday_of_month(day_of_week_type dow, month_type m) :
330 //! Return a concrete date when provided with a year specific year.
331 date_type get_date(year_type year) const
333 date_type d(year, month_, calendar_type::end_of_month_day(year,month_));
334 duration_type one_day(1);
335 while (dow_ != d.day_of_week()) {
340 // added for streaming
341 month_type month() const
345 day_of_week_type day_of_week() const
349 //! Returns string suitable for use in POSIX time zone string
350 /*! Returns a string formatted as "M4.5.0" ==> last Sunday in April. */
351 virtual std::string to_string() const
353 std::ostringstream ss;
355 << static_cast<int>(month_) << '.'
357 << static_cast<int>(dow_);
362 day_of_week_type dow_;
366 //! Calculate something like "First Sunday after Jan 1,2002
367 /*! Date generator that takes a date and finds kday after
369 typedef boost::date_time::first_kday_after<date> firstkdayafter;
370 firstkdayafter fkaf(Monday);
371 fkaf.get_date(date(2002,Feb,1));
375 template<class date_type>
376 class first_kday_after
379 typedef typename date_type::calendar_type calendar_type;
380 typedef typename calendar_type::day_of_week_type day_of_week_type;
381 typedef typename date_type::duration_type duration_type;
382 first_kday_after(day_of_week_type dow) :
385 //! Return next kday given.
386 date_type get_date(date_type start_day) const
388 duration_type one_day(1);
389 date_type d = start_day + one_day;
390 while (dow_ != d.day_of_week()) {
395 // added for streaming
396 day_of_week_type day_of_week() const
401 day_of_week_type dow_;
404 //! Calculate something like "First Sunday before Jan 1,2002
405 /*! Date generator that takes a date and finds kday after
407 typedef boost::date_time::first_kday_before<date> firstkdaybefore;
408 firstkdaybefore fkbf(Monday);
409 fkbf.get_date(date(2002,Feb,1));
413 template<class date_type>
414 class first_kday_before
417 typedef typename date_type::calendar_type calendar_type;
418 typedef typename calendar_type::day_of_week_type day_of_week_type;
419 typedef typename date_type::duration_type duration_type;
420 first_kday_before(day_of_week_type dow) :
423 //! Return next kday given.
424 date_type get_date(date_type start_day) const
426 duration_type one_day(1);
427 date_type d = start_day - one_day;
428 while (dow_ != d.day_of_week()) {
433 // added for streaming
434 day_of_week_type day_of_week() const
439 day_of_week_type dow_;
442 //! Calculates the number of days until the next weekday
443 /*! Calculates the number of days until the next weekday.
444 * If the date given falls on a Sunday and the given weekday
445 * is Tuesday the result will be 2 days */
446 template<typename date_type, class weekday_type>
448 typename date_type::duration_type days_until_weekday(const date_type& d, const weekday_type& wd)
450 typedef typename date_type::duration_type duration_type;
451 duration_type wks(0);
452 duration_type dd(wd.as_number() - d.day_of_week().as_number());
453 if(dd.is_negative()){
454 wks = duration_type(7);
459 //! Calculates the number of days since the previous weekday
460 /*! Calculates the number of days since the previous weekday
461 * If the date given falls on a Sunday and the given weekday
462 * is Tuesday the result will be 5 days. The answer will be a positive
463 * number because Tuesday is 5 days before Sunday, not -5 days before. */
464 template<typename date_type, class weekday_type>
466 typename date_type::duration_type days_before_weekday(const date_type& d, const weekday_type& wd)
468 typedef typename date_type::duration_type duration_type;
469 duration_type wks(0);
470 duration_type dd(wd.as_number() - d.day_of_week().as_number());
472 wks = duration_type(7);
474 // we want a number of days, not an offset. The value returned must
475 // be zero or larger.
479 //! Generates a date object representing the date of the following weekday from the given date
480 /*! Generates a date object representing the date of the following
481 * weekday from the given date. If the date given is 2004-May-9
482 * (a Sunday) and the given weekday is Tuesday then the resulting date
483 * will be 2004-May-11. */
484 template<class date_type, class weekday_type>
486 date_type next_weekday(const date_type& d, const weekday_type& wd)
488 return d + days_until_weekday(d, wd);
491 //! Generates a date object representing the date of the previous weekday from the given date
492 /*! Generates a date object representing the date of the previous
493 * weekday from the given date. If the date given is 2004-May-9
494 * (a Sunday) and the given weekday is Tuesday then the resulting date
495 * will be 2004-May-4. */
496 template<class date_type, class weekday_type>
498 date_type previous_weekday(const date_type& d, const weekday_type& wd)
500 return d - days_before_weekday(d, wd);
503 } } //namespace date_time