Chris@16: #ifndef _DATE_TIME_ADJUST_FUNCTORS_HPP___
Chris@16: #define _DATE_TIME_ADJUST_FUNCTORS_HPP___
Chris@16: 
Chris@16: /* Copyright (c) 2002,2003 CrystalClear Software, Inc.
Chris@16:  * Use, modification and distribution is subject to the 
Chris@16:  * Boost Software License, Version 1.0. (See accompanying
Chris@16:  * file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
Chris@16:  * Author: Jeff Garland, Bart Garst
Chris@101:  * $Date$
Chris@16:  */
Chris@16: 
Chris@16: #include "boost/date_time/date.hpp"
Chris@16: #include "boost/date_time/wrapping_int.hpp"
Chris@16: 
Chris@16: namespace boost {
Chris@16: namespace date_time {
Chris@16:   
Chris@16: 
Chris@16:   //! Functor to iterate a fixed number of days
Chris@16:   template<class date_type>
Chris@16:   class day_functor 
Chris@16:   {
Chris@16:   public:
Chris@16:     typedef typename date_type::duration_type duration_type;
Chris@16:     day_functor(int f) : f_(f) {}
Chris@16:     duration_type get_offset(const date_type& d) const 
Chris@16:     {
Chris@16:       // why is 'd' a parameter???
Chris@16:       // fix compiler warnings
Chris@16:       d.year();
Chris@16:       return duration_type(f_);
Chris@16:     }
Chris@16:     duration_type get_neg_offset(const date_type& d) const 
Chris@16:     {
Chris@16:       // fix compiler warnings
Chris@16:       d.year();
Chris@16:       return duration_type(-f_);
Chris@16:     }
Chris@16:   private:
Chris@16:     int f_;
Chris@16:   };
Chris@16: 
Chris@16: 
Chris@16:   //! Provides calculation to find next nth month given a date
Chris@16:   /*! This adjustment function provides the logic for 'month-based'
Chris@16:    *  advancement on a ymd based calendar.  The policy it uses 
Chris@16:    *  to handle the non existant end of month days is to back
Chris@16:    *  up to the last day of the month.  Also, if the starting
Chris@16:    *  date is the last day of a month, this functor will attempt
Chris@16:    *  to adjust to the end of the month.
Chris@16: 
Chris@16:    */
Chris@16:   template<class date_type>
Chris@16:   class month_functor 
Chris@16:   {
Chris@16:   public:
Chris@16:     typedef typename date_type::duration_type duration_type;
Chris@16:     typedef typename date_type::calendar_type cal_type;
Chris@16:     typedef typename cal_type::ymd_type ymd_type;
Chris@16:     typedef typename cal_type::day_type day_type;
Chris@16: 
Chris@16:     month_functor(int f) : f_(f), origDayOfMonth_(0) {}
Chris@16:     duration_type get_offset(const date_type& d) const 
Chris@16:     {
Chris@16:       ymd_type ymd(d.year_month_day());
Chris@16:       if (origDayOfMonth_ == 0) {
Chris@16:         origDayOfMonth_ = ymd.day;
Chris@16:         day_type endOfMonthDay(cal_type::end_of_month_day(ymd.year,ymd.month));
Chris@16:         if (endOfMonthDay == ymd.day) {
Chris@16:           origDayOfMonth_ = -1; //force the value to the end of month
Chris@16:         }
Chris@16:       }
Chris@16:       typedef date_time::wrapping_int2<short,1,12> wrap_int2;
Chris@16:       typedef typename wrap_int2::int_type int_type;
Chris@16:       wrap_int2 wi(ymd.month);
Chris@16:       //calc the year wrap around, add() returns 0 or 1 if wrapped
Chris@16:       int_type year = wi.add(static_cast<int_type>(f_)); 
Chris@16:       year = static_cast<int_type>(year + ymd.year); //calculate resulting year
Chris@16: //       std::cout << "trace wi: " << wi.as_int() << std::endl;
Chris@16: //       std::cout << "trace year: " << year << std::endl;
Chris@16:       //find the last day for the new month
Chris@16:       day_type resultingEndOfMonthDay(cal_type::end_of_month_day(year, wi.as_int()));
Chris@16:       //original was the end of month -- force to last day of month
Chris@16:       if (origDayOfMonth_ == -1) {
Chris@16:         return date_type(year, wi.as_int(), resultingEndOfMonthDay) - d;
Chris@16:       }
Chris@16:       day_type dayOfMonth = origDayOfMonth_;
Chris@16:       if (dayOfMonth > resultingEndOfMonthDay) {
Chris@16:         dayOfMonth = resultingEndOfMonthDay;
Chris@16:       }
Chris@16:       return date_type(year, wi.as_int(), dayOfMonth) - d;
Chris@16:     }
Chris@16:     //! Returns a negative duration_type
Chris@16:     duration_type get_neg_offset(const date_type& d) const 
Chris@16:     {
Chris@16:       ymd_type ymd(d.year_month_day());
Chris@16:       if (origDayOfMonth_ == 0) {
Chris@16:         origDayOfMonth_ = ymd.day;
Chris@16:         day_type endOfMonthDay(cal_type::end_of_month_day(ymd.year,ymd.month));
Chris@16:         if (endOfMonthDay == ymd.day) {
Chris@16:           origDayOfMonth_ = -1; //force the value to the end of month
Chris@16:         }
Chris@16:       }
Chris@16:       typedef date_time::wrapping_int2<short,1,12> wrap_int2;
Chris@16:       typedef typename wrap_int2::int_type int_type;
Chris@16:       wrap_int2 wi(ymd.month);
Chris@16:       //calc the year wrap around, add() returns 0 or 1 if wrapped
Chris@16:       int_type year = wi.subtract(static_cast<int_type>(f_)); 
Chris@16:       year = static_cast<int_type>(year + ymd.year); //calculate resulting year
Chris@16:       //find the last day for the new month
Chris@16:       day_type resultingEndOfMonthDay(cal_type::end_of_month_day(year, wi.as_int()));
Chris@16:       //original was the end of month -- force to last day of month
Chris@16:       if (origDayOfMonth_ == -1) {
Chris@16:         return date_type(year, wi.as_int(), resultingEndOfMonthDay) - d;
Chris@16:       }
Chris@16:       day_type dayOfMonth = origDayOfMonth_;
Chris@16:       if (dayOfMonth > resultingEndOfMonthDay) {
Chris@16:         dayOfMonth = resultingEndOfMonthDay;
Chris@16:       }
Chris@16:       return date_type(year, wi.as_int(), dayOfMonth) - d;
Chris@16:     }
Chris@16:   private:
Chris@16:     int f_;
Chris@16:     mutable short origDayOfMonth_;
Chris@16:   };
Chris@16: 
Chris@16: 
Chris@16:   //! Functor to iterate a over weeks
Chris@16:   template<class date_type>
Chris@16:   class week_functor 
Chris@16:   {
Chris@16:   public:
Chris@16:     typedef typename date_type::duration_type duration_type;
Chris@16:     typedef typename date_type::calendar_type calendar_type;
Chris@16:     week_functor(int f) : f_(f) {}
Chris@16:     duration_type get_offset(const date_type& d) const 
Chris@16:     {
Chris@16:       // why is 'd' a parameter???
Chris@16:       // fix compiler warnings
Chris@16:       d.year();
Chris@16:       return duration_type(f_*calendar_type::days_in_week());
Chris@16:     }
Chris@16:     duration_type get_neg_offset(const date_type& d) const 
Chris@16:     {
Chris@16:       // fix compiler warnings
Chris@16:       d.year();
Chris@16:       return duration_type(-f_*calendar_type::days_in_week());
Chris@16:     }
Chris@16:   private:
Chris@16:     int f_;
Chris@16:   };
Chris@16: 
Chris@16:   //! Functor to iterate by a year adjusting for leap years
Chris@16:   template<class date_type>
Chris@16:   class year_functor 
Chris@16:   {
Chris@16:   public:
Chris@16:     //typedef typename date_type::year_type year_type;
Chris@16:     typedef typename date_type::duration_type duration_type;
Chris@16:     year_functor(int f) : _mf(f * 12) {}
Chris@16:     duration_type get_offset(const date_type& d) const 
Chris@16:     {
Chris@16:       return _mf.get_offset(d);
Chris@16:     }
Chris@16:     duration_type get_neg_offset(const date_type& d) const 
Chris@16:     {
Chris@16:       return _mf.get_neg_offset(d);
Chris@16:     }
Chris@16:   private:
Chris@16:     month_functor<date_type> _mf;
Chris@16:   };
Chris@16: 
Chris@16:   
Chris@16: } }//namespace date_time
Chris@16: 
Chris@16: 
Chris@16: #endif
Chris@16: