boost/date_time/time.hpp

   1 #ifndef DATE_TIME_TIME_HPP___
   2 #define DATE_TIME_TIME_HPP___
   3
   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
   9  * $Date$
  10  */
  11
  12
  13 /*! @file time.hpp
  14   This file contains the interface for the time associated classes.
  15 */
  16 #include <string>
  17 #include <boost/operators.hpp>
  18 #include <boost/date_time/time_defs.hpp>
  19 #include <boost/date_time/special_defs.hpp>
  20
  21 namespace boost {
  22 namespace date_time {
  23
  24   //! Representation of a precise moment in time, including the date.
  25   /*!
  26     This class is a skeleton for the interface of a temporal type
  27     with a resolution that is higher than a day.  It is intended that
  28     this class be the base class and that the actual time
  29     class be derived using the BN pattern.  In this way, the derived
  30     class can make decisions such as 'should there be a default constructor'
  31     and what should it set its value to, should there be optional constructors
  32     say allowing only an time_durations that generate a time from a clock,etc.
  33     So, in fact multiple time types can be created for a time_system with
  34     different construction policies, and all of them can perform basic
  35     operations by only writing a copy constructor.  Finally, compiler
  36     errors are also shorter.
  37
  38     The real behavior of the time class is provided by the time_system
  39     template parameter.  This class must provide all the logic
  40     for addition, subtraction, as well as define all the interface
  41     types.
  42
  43   */
  44
  45   template <class T, class time_system>
  46   class base_time : private
  47       boost::less_than_comparable<T
  48     , boost::equality_comparable<T
  49       > >
  50   {
  51   public:
  52     typedef T time_type;
  53     typedef typename time_system::time_rep_type time_rep_type;
  54     typedef typename time_system::date_type date_type;
  55     typedef typename time_system::date_duration_type date_duration_type;
  56     typedef typename time_system::time_duration_type time_duration_type;
  57     //typedef typename time_system::hms_type hms_type;
  58
  59     base_time(const date_type& day,
  60               const time_duration_type& td,
  61               dst_flags dst=not_dst) :
  62       time_(time_system::get_time_rep(day, td, dst))
  63     {}
  64     base_time(special_values sv) :
  65       time_(time_system::get_time_rep(sv))
  66     {}
  67     base_time(const time_rep_type& rhs) :
  68       time_(rhs)
  69     {}
  70     date_type date() const
  71     {
  72       return time_system::get_date(time_);
  73     }
  74     time_duration_type time_of_day() const
  75     {
  76       return time_system::get_time_of_day(time_);
  77     }
  78     /*! Optional bool parameter will return time zone as an offset
  79      * (ie "+07:00"). Empty string is returned for classes that do
  80      * not use a time_zone */
  81     std::string zone_name(bool /*as_offset*/=false) const
  82     {
  83       return time_system::zone_name(time_);
  84     }
  85     /*! Optional bool parameter will return time zone as an offset
  86      * (ie "+07:00"). Empty string is returned for classes that do
  87      * not use a time_zone */
  88     std::string zone_abbrev(bool /*as_offset*/=false) const
  89     {
  90       return time_system::zone_name(time_);
  91     }
  92     //! An empty string is returned for classes that do not use a time_zone
  93     std::string zone_as_posix_string() const
  94     {
  95       return std::string();
  96     }
  97
  98     //! check to see if date is not a value
  99     bool is_not_a_date_time()  const
 100     {
 101       return time_.is_not_a_date_time();
 102     }
 103     //! check to see if date is one of the infinity values
 104     bool is_infinity()  const
 105     {
 106       return (is_pos_infinity() || is_neg_infinity());
 107     }
 108     //! check to see if date is greater than all possible dates
 109     bool is_pos_infinity()  const
 110     {
 111       return time_.is_pos_infinity();
 112     }
 113     //! check to see if date is greater than all possible dates
 114     bool is_neg_infinity()  const
 115     {
 116       return time_.is_neg_infinity();
 117     }
 118     //! check to see if time is a special value
 119     bool is_special() const
 120     {
 121       return(is_not_a_date_time() || is_infinity());
 122     }
 123     //!Equality operator -- others generated by boost::equality_comparable
 124     bool operator==(const time_type& rhs) const
 125     {
 126       return time_system::is_equal(time_,rhs.time_);
 127     }
 128     //!Equality operator -- others generated by boost::less_than_comparable
 129     bool operator<(const time_type& rhs) const
 130     {
 131       return time_system::is_less(time_,rhs.time_);
 132     }
 133     //! difference between two times
 134     time_duration_type operator-(const time_type& rhs) const
 135     {
 136       return time_system::subtract_times(time_, rhs.time_);
 137     }
 138     //! add date durations
 139     time_type operator+(const date_duration_type& dd) const
 140     {
 141       return time_system::add_days(time_, dd);
 142     }
 143     time_type operator+=(const date_duration_type& dd)
 144     {
 145       time_ = (time_system::get_time_rep(date() + dd, time_of_day()));
 146       return time_type(time_);
 147     }
 148     //! subtract date durations
 149     time_type operator-(const date_duration_type& dd) const
 150     {
 151       return time_system::subtract_days(time_, dd);
 152     }
 153     time_type operator-=(const date_duration_type& dd)
 154     {
 155       time_ = (time_system::get_time_rep(date() - dd, time_of_day()));
 156       return time_type(time_);
 157     }
 158     //! add time durations
 159     time_type operator+(const time_duration_type& td) const
 160     {
 161       return time_type(time_system::add_time_duration(time_, td));
 162     }
 163     time_type operator+=(const time_duration_type& td)
 164     {
 165       time_ = (time_system::get_time_rep(date(), time_of_day() + td));
 166       return time_type(time_);
 167     }
 168     //! subtract time durations
 169     time_type operator-(const time_duration_type& rhs) const
 170     {
 171       return time_system::subtract_time_duration(time_, rhs);
 172     }
 173     time_type operator-=(const time_duration_type& td)
 174     {
 175       time_ = (time_system::get_time_rep(date(), time_of_day() - td));
 176       return time_type(time_);
 177     }
 178
 179   protected:
 180     time_rep_type time_;
 181   };
 182
 183
 184
 185
 186
 187 } } //namespace date_time::boost
 188
 189
 190 #endif
 191