1#ifndef _GREGORIAN__CONVERSION_HPP___
2#define _GREGORIAN__CONVERSION_HPP___
3
4/* Copyright (c) 2004-2005 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#include <cstring>
13#include <string>
14#include <stdexcept>
15#include <boost/throw_exception.hpp>
16#include <boost/date_time/c_time.hpp>
17#include <boost/date_time/special_defs.hpp>
18#include <boost/date_time/gregorian/gregorian_types.hpp>
19
20namespace boost {
21
22namespace gregorian {
23
24 //! Converts a date to a tm struct. Throws out_of_range exception if date is a special value
25 inline
26 std::tm to_tm(const date& d)
27 {
28 if (d.is_special())
29 {
30 std::string s = "tm unable to handle ";
31 switch (d.as_special())
32 {
33 case date_time::not_a_date_time:
34 s += "not-a-date-time value"; break;
35 case date_time::neg_infin:
36 s += "-infinity date value"; break;
37 case date_time::pos_infin:
38 s += "+infinity date value"; break;
39 default:
40 s += "a special date value"; break;
41 }
42 boost::throw_exception(e: std::out_of_range(s));
43 }
44
45 std::tm datetm;
46 std::memset(s: &datetm, c: 0, n: sizeof(datetm));
47 boost::gregorian::date::ymd_type ymd = d.year_month_day();
48 datetm.tm_year = ymd.year - 1900;
49 datetm.tm_mon = ymd.month - 1;
50 datetm.tm_mday = ymd.day;
51 datetm.tm_wday = d.day_of_week();
52 datetm.tm_yday = d.day_of_year() - 1;
53 datetm.tm_isdst = -1; // negative because not enough info to set tm_isdst
54 return datetm;
55 }
56
57 //! Converts a tm structure into a date dropping the any time values.
58 inline
59 date date_from_tm(const std::tm& datetm)
60 {
61 return date(static_cast<unsigned short>(datetm.tm_year+1900),
62 static_cast<unsigned short>(datetm.tm_mon+1),
63 static_cast<unsigned short>(datetm.tm_mday));
64 }
65
66} } //namespace boost::gregorian
67
68#endif
69

source code of include/boost/date_time/gregorian/conversion.hpp