1#ifndef DATE_TIME_DATE_DURATION__
2#define DATE_TIME_DATE_DURATION__
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
13#include <boost/operators.hpp>
14#include <boost/date_time/special_defs.hpp>
15
16namespace boost {
17namespace date_time {
18
19
20 //! Duration type with date level resolution
21 template<class duration_rep_traits>
22 class date_duration : private
23 boost::less_than_comparable1< date_duration< duration_rep_traits >
24 , boost::equality_comparable1< date_duration< duration_rep_traits >
25 , boost::addable1< date_duration< duration_rep_traits >
26 , boost::subtractable1< date_duration< duration_rep_traits >
27 , boost::dividable2< date_duration< duration_rep_traits >, int
28 > > > > >
29 {
30 public:
31 typedef typename duration_rep_traits::int_type duration_rep_type;
32 typedef typename duration_rep_traits::impl_type duration_rep;
33
34 //! Construct from a day count
35 explicit date_duration(duration_rep day_count) : days_(day_count) {}
36
37 /*! construct from special_values - only works when
38 * instantiated with duration_traits_adapted */
39 date_duration(special_values sv) :
40 days_(duration_rep::from_special(sv))
41 {}
42
43 // copy constructor required for addable<> & subtractable<>
44 //! Construct from another date_duration (Copy Constructor)
45 date_duration(const date_duration<duration_rep_traits>& other) :
46 days_(other.days_)
47 {}
48
49 //! returns days_ as it's instantiated type - used for streaming
50 duration_rep get_rep()const
51 {
52 return days_;
53 }
54 bool is_special()const
55 {
56 return days_.is_special();
57 }
58 //! returns days as value, not object.
59 duration_rep_type days() const
60 {
61 return duration_rep_traits::as_number(days_);
62 }
63 //! Returns the smallest duration -- used by to calculate 'end'
64 static date_duration unit()
65 {
66 return date_duration<duration_rep_traits>(1);
67 }
68 //! Equality
69 bool operator==(const date_duration& rhs) const
70 {
71 return days_ == rhs.days_;
72 }
73 //! Less
74 bool operator<(const date_duration& rhs) const
75 {
76 return days_ < rhs.days_;
77 }
78
79 /* For shortcut operators (+=, -=, etc) simply using
80 * "days_ += days_" may not work. If instantiated with
81 * an int_adapter, shortcut operators are not present,
82 * so this will not compile */
83
84 //! Subtract another duration -- result is signed
85 date_duration& operator-=(const date_duration& rhs)
86 {
87 //days_ -= rhs.days_;
88 days_ = days_ - rhs.days_;
89 return *this;
90 }
91 //! Add a duration -- result is signed
92 date_duration& operator+=(const date_duration& rhs)
93 {
94 days_ = days_ + rhs.days_;
95 return *this;
96 }
97
98 //! unary- Allows for dd = -date_duration(2); -> dd == -2
99 date_duration operator-() const
100 {
101 return date_duration<duration_rep_traits>(get_rep() * (-1));
102 }
103 //! Division operations on a duration with an integer.
104 date_duration& operator/=(int divisor)
105 {
106 days_ = days_ / divisor;
107 return *this;
108 }
109
110 //! return sign information
111 bool is_negative() const
112 {
113 return days_ < 0;
114 }
115
116 private:
117 duration_rep days_;
118 };
119
120
121 /*! Struct for instantiating date_duration with <b>NO</b> special values
122 * functionality. Allows for transparent implementation of either
123 * date_duration<long> or date_duration<int_adapter<long> > */
124 struct duration_traits_long
125 {
126 typedef long int_type;
127 typedef long impl_type;
128 static int_type as_number(impl_type i) { return i; }
129 };
130
131 /*! Struct for instantiating date_duration <b>WITH</b> special values
132 * functionality. Allows for transparent implementation of either
133 * date_duration<long> or date_duration<int_adapter<long> > */
134 struct duration_traits_adapted
135 {
136 typedef long int_type;
137 typedef boost::date_time::int_adapter<long> impl_type;
138 static int_type as_number(impl_type i) { return i.as_number(); }
139 };
140
141
142} } //namspace date_time
143
144
145#endif
146
147

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