boost/date_time/gregorian/conversion.hpp

   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 <string>
  13 #include <stdexcept>
  14 #include <boost/throw_exception.hpp>
  15 #include <boost/date_time/gregorian/gregorian_types.hpp>
  16 #include <boost/date_time/c_time.hpp>
  17 #if defined(USE_DATE_TIME_PRE_1_33_FACET_IO)
  18 #  if defined(BOOST_DATE_TIME_INCLUDE_LIMITED_HEADERS)
  19 #    include <boost/date_time/gregorian/formatters_limited.hpp>
  20 #  else
  21 #    include <boost/date_time/gregorian/formatters.hpp>
  22 #  endif // BOOST_DATE_TIME_INCLUDE_LIMITED_HEADERS
  23 #else
  24 #  include <sstream>
  25 #  include <boost/date_time/gregorian/gregorian_io.hpp>
  26 #endif // USE_DATE_TIME_PRE_1_33_FACET_IO
  27
  28 namespace boost {
  29
  30 namespace gregorian {
  31
  32
  33   //! Converts a date to a tm struct. Throws out_of_range exception if date is a special value
  34   inline
  35   std::tm to_tm(const date& d)
  36   {
  37     if(d.is_pos_infinity() || d.is_neg_infinity() || d.is_not_a_date()){
  38       std::string s = "tm unable to handle date value of ";
  39 #if defined(USE_DATE_TIME_PRE_1_33_FACET_IO)
  40       s += to_simple_string(d);
  41 #else
  42       std::ostringstream ss;
  43       ss << d;
  44       s += ss.str();
  45 #endif // USE_DATE_TIME_PRE_1_33_FACET_IO
  46       boost::throw_exception(std::out_of_range(s));
  47     }
  48     std::tm datetm;
  49     boost::gregorian::date::ymd_type ymd = d.year_month_day();
  50     datetm.tm_year = ymd.year-1900;
  51     datetm.tm_mon = ymd.month-1;
  52     datetm.tm_mday = ymd.day;
  53     datetm.tm_wday = d.day_of_week();
  54     datetm.tm_yday = d.day_of_year()-1;
  55     datetm.tm_hour = datetm.tm_min = datetm.tm_sec = 0;
  56     datetm.tm_isdst = -1; // negative because not enough info to set tm_isdst
  57     return datetm;
  58   }
  59
  60   //! Converts a tm structure into a date dropping the any time values.
  61   inline
  62   date date_from_tm(const std::tm& datetm)
  63   {
  64     return date(static_cast<unsigned short>(datetm.tm_year+1900),
  65                 static_cast<unsigned short>(datetm.tm_mon+1),
  66                 static_cast<unsigned short>(datetm.tm_mday));
  67   }
  68
  69
  70 } } //namespace boost::gregorian
  71
  72
  73
  74
  75 #endif
  76