source: NonGTP/Boost/boost/date_time/date_duration.hpp @ 857

Revision 857, 4.4 KB checked in by igarcia, 19 years ago (diff)
Line 
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 or http://www.boost.org/LICENSE-1.0)
8 * Author: Jeff Garland, Bart Garst
9 * $Date: 2003/12/03 01:56:13 $
10 */
11
12
13#include <boost/operators.hpp>
14
15namespace boost {
16namespace date_time {
17
18
19  //! Duration type with date level resolution
20  template<class duration_rep_traits>
21  class date_duration : private
22              boost::less_than_comparable<date_duration< duration_rep_traits>
23            , boost::equality_comparable< date_duration< duration_rep_traits>
24            , boost::addable< date_duration< duration_rep_traits>
25            , boost::subtractable< date_duration< duration_rep_traits>
26            > > > >
27  {
28  public:
29    typedef typename duration_rep_traits::int_type duration_rep_type;
30    typedef typename duration_rep_traits::impl_type duration_rep;
31   
32    //! Construct from a day count
33    explicit date_duration(duration_rep day_count) : days_(day_count) {};
34   
35    /*! construct from special_values - only works when
36     * instantiated with duration_traits_adapted */
37    date_duration(special_values sv) :
38            days_(duration_rep::from_special(sv))
39    {}
40
41    // copy constructor required for addable<> & subtractable<>
42    //! Construct from another date_duration (Copy Constructor)
43    date_duration(const date_duration<duration_rep_traits>& other) :
44            days_(other.days_)
45    {}
46
47    //! returns days_ as it's instantiated type - used for streaming
48    duration_rep get_rep()const
49    {
50        return days_;
51    }
52    bool is_special()const
53    {
54        return days_.is_special();
55    }
56    //! returns days as value, not object.
57    duration_rep_type days() const
58    {
59        return duration_rep_traits::as_number(days_);
60    }
61    //! Returns the smallest duration -- used by to calculate 'end'
62    static date_duration unit()
63    {
64        return date_duration<duration_rep_traits>(1);
65    }
66    //! Equality
67    bool operator==(const date_duration& rhs) const
68    {
69        return days_ == rhs.days_;
70    }
71    //! Less
72    bool operator<(const date_duration& rhs) const
73    {
74        return days_ < rhs.days_;
75    }
76
77    /* For shortcut operators (+=, -=, etc) simply using
78     * "days_ += days_" may not work. If instantiated with
79     * an int_adapter, shortcut operators are not present,
80     * so this will not compile */
81
82    //! Subtract another duration -- result is signed
83    date_duration operator-=(const date_duration& rhs)
84    {
85        //days_ -= rhs.days_;
86        days_ = days_ - rhs.days_;
87        return *this;
88    }
89    //! Add a duration -- result is signed
90    date_duration operator+=(const date_duration& rhs)
91    {
92        days_ = days_ + rhs.days_;
93        return *this;
94    }
95
96    //! unary- Allows for dd = -date_duration(2); -> dd == -2
97    date_duration operator-()const
98    {
99        return date_duration<duration_rep_traits>(get_rep() * (-1));
100    }
101    //! Division operations on a duration with an integer.
102    date_duration<duration_rep_traits> operator/=(int divisor)
103    {
104        days_ = days_ / divisor;
105        return *this;
106    }
107    date_duration<duration_rep_traits> operator/(int divisor)
108    {
109        return date_duration<duration_rep_traits>(days_ / divisor);
110    }
111
112    //! return sign information
113    bool is_negative() const
114    {
115        return days_ < 0;
116    }
117  private:
118    duration_rep days_;
119  };
120
121
122  /*! Struct for instantiating date_duration with <b>NO</b> special values
123   * functionality. Allows for transparent implementation of either
124   * date_duration<long> or date_duration<int_adapter<long> > */
125  struct duration_traits_long
126  {
127    typedef long int_type;
128    typedef long impl_type;
129    static int_type as_number(impl_type i) { return i; };
130  };
131
132  /*! Struct for instantiating date_duration <b>WITH</b> special values
133   * functionality. Allows for transparent implementation of either
134   * date_duration<long> or date_duration<int_adapter<long> > */
135  struct duration_traits_adapted
136  {
137    typedef long int_type;
138    typedef boost::date_time::int_adapter<long> impl_type;
139    static int_type as_number(impl_type i) { return i.as_number(); };
140  };
141 
142
143} } //namspace date_time
144
145
146#endif
147
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