boost/date_time/local_time/date_duration_operators.hpp

   1 #ifndef LOCAL_TIME_DATE_DURATION_OPERATORS_HPP___
   2 #define LOCAL_TIME_DATE_DURATION_OPERATORS_HPP___
   3
   4 /* Copyright (c) 2004 CrystalClear Software, Inc.
   5  * Subject to the Boost Software License, Version 1.0.
   6  * (See accompanying file LICENSE_1_0.txt or
   7  * http://www.boost.org/LICENSE_1_0.txt)
   8  * Author: Jeff Garland, Bart Garst
   9  * $Date$
  10  */
  11
  12 #include "boost/date_time/gregorian/greg_duration_types.hpp"
  13 #include "boost/date_time/local_time/local_date_time.hpp"
  14
  15 namespace boost {
  16 namespace local_time {
  17
  18   /*!@file date_duration_operators.hpp Operators for local_date_time and
  19    * optional gregorian types. Operators use snap-to-end-of-month behavior.
  20    * Further details on this behavior can be found in reference for
  21    * date_time/date_duration_types.hpp and documentation for
  22    * month and year iterators.
  23    */
  24
  25
  26   /*! Adds a months object and a local_date_time. Result will be same
  27    * day-of-month as local_date_time unless original day was the last day of month.
  28    * see date_time::months_duration for more details */
  29   inline
  30   local_date_time
  31   operator+(const local_date_time& t, const boost::gregorian::months& m)
  32   {
  33     return t + m.get_offset(t.utc_time().date());
  34   }
  35
  36   /*! Adds a months object to a local_date_time. Result will be same
  37    * day-of-month as local_date_time unless original day was the last day of month.
  38    * see date_time::months_duration for more details */
  39   inline
  40   local_date_time
  41   operator+=(local_date_time& t, const boost::gregorian::months& m)
  42   {
  43     return t += m.get_offset(t.utc_time().date());
  44   }
  45
  46   /*! Subtracts a months object and a local_date_time. Result will be same
  47    * day-of-month as local_date_time unless original day was the last day of month.
  48    * see date_time::months_duration for more details */
  49   inline
  50   local_date_time
  51   operator-(const local_date_time& t, const boost::gregorian::months& m)
  52   {
  53     // get_neg_offset returns a negative duration, so we add
  54     return t + m.get_neg_offset(t.utc_time().date());
  55   }
  56
  57   /*! Subtracts a months object from a local_date_time. Result will be same
  58    * day-of-month as local_date_time unless original day was the last day of month.
  59    * see date_time::months_duration for more details */
  60   inline
  61   local_date_time
  62   operator-=(local_date_time& t, const boost::gregorian::months& m)
  63   {
  64     // get_neg_offset returns a negative duration, so we add
  65     return t += m.get_neg_offset(t.utc_time().date());
  66   }
  67
  68   // local_date_time & years
  69
  70   /*! Adds a years object and a local_date_time. Result will be same
  71    * month and day-of-month as local_date_time unless original day was the
  72    * last day of month. see date_time::years_duration for more details */
  73   inline
  74   local_date_time
  75   operator+(const local_date_time& t, const boost::gregorian::years& y)
  76   {
  77     return t + y.get_offset(t.utc_time().date());
  78   }
  79
  80   /*! Adds a years object to a local_date_time. Result will be same
  81    * month and day-of-month as local_date_time unless original day was the
  82    * last day of month. see date_time::years_duration for more details */
  83   inline
  84   local_date_time
  85   operator+=(local_date_time& t, const boost::gregorian::years& y)
  86   {
  87     return t += y.get_offset(t.utc_time().date());
  88   }
  89
  90   /*! Subtracts a years object and a local_date_time. Result will be same
  91    * month and day-of-month as local_date_time unless original day was the
  92    * last day of month. see date_time::years_duration for more details */
  93   inline
  94   local_date_time
  95   operator-(const local_date_time& t, const boost::gregorian::years& y)
  96   {
  97     // get_neg_offset returns a negative duration, so we add
  98     return t + y.get_neg_offset(t.utc_time().date());
  99   }
 100
 101   /*! Subtracts a years object from a local_date_time. Result will be same
 102    * month and day-of-month as local_date_time unless original day was the
 103    * last day of month. see date_time::years_duration for more details */
 104   inline
 105   local_date_time
 106   operator-=(local_date_time& t, const boost::gregorian::years& y)
 107   {
 108     // get_neg_offset returns a negative duration, so we add
 109     return t += y.get_neg_offset(t.utc_time().date());
 110   }
 111
 112
 113 }} // namespaces
 114
 115 #endif // LOCAL_TIME_DATE_DURATION_OPERATORS_HPP___