boost/date_time/date_formatting_limited.hpp

   1 #ifndef DATE_TIME_DATE_FORMATTING_LIMITED_HPP___
   2 #define DATE_TIME_DATE_FORMATTING_LIMITED_HPP___
   3
   4 /* Copyright (c) 2002-2004 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 "boost/date_time/iso_format.hpp"
  13 #include "boost/date_time/compiler_config.hpp"
  14 #include <string>
  15 #include <sstream>
  16 #include <iomanip>
  17
  18
  19 namespace boost {
  20 namespace date_time {
  21
  22   //! Formats a month as as string into an ostream
  23   template<class month_type, class format_type>
  24   class month_formatter
  25   {
  26   public:
  27     //! Formats a month as as string into an ostream
  28     /*! This function demands that month_type provide
  29      *  functions for converting to short and long strings
  30      *  if that capability is used.
  31      */
  32     static std::ostream& format_month(const month_type& month,
  33                                       std::ostream& os)
  34     {
  35       switch (format_type::month_format())
  36       {
  37         case month_as_short_string:
  38         {
  39           os << month.as_short_string();
  40           break;
  41         }
  42         case month_as_long_string:
  43         {
  44           os << month.as_long_string();
  45           break;
  46         }
  47         case month_as_integer:
  48         {
  49           os << std::setw(2) << std::setfill('0') << month.as_number();
  50           break;
  51         }
  52
  53       }
  54       return os;
  55     } // format_month
  56   };
  57
  58
  59   //! Convert ymd to a standard string formatting policies
  60   template<class ymd_type, class format_type>
  61   class ymd_formatter
  62   {
  63   public:
  64     //! Convert ymd to a standard string formatting policies
  65     /*! This is standard code for handling date formatting with
  66      *  year-month-day based date information.  This function
  67      *  uses the format_type to control whether the string will
  68      *  contain separator characters, and if so what the character
  69      *  will be.  In addtion, it can format the month as either
  70      *  an integer or a string as controled by the formatting
  71      *  policy
  72      */
  73     static std::string ymd_to_string(ymd_type ymd)
  74     {
  75       typedef typename ymd_type::month_type month_type;
  76       std::ostringstream ss;
  77       ss << ymd.year;
  78       if (format_type::has_date_sep_chars()) {
  79         ss << format_type::month_sep_char();
  80       }
  81       //this name is a bit ugly, oh well....
  82       month_formatter<month_type,format_type>::format_month(ymd.month, ss);
  83       if (format_type::has_date_sep_chars()) {
  84         ss << format_type::day_sep_char();
  85       }
  86       ss  << std::setw(2) << std::setfill('0')
  87           << ymd.day;
  88       return ss.str();
  89     }
  90   };
  91
  92
  93   //! Convert a date to string using format policies
  94   template<class date_type, class format_type>
  95   class date_formatter
  96   {
  97   public:
  98     //! Convert to a date to standard string using format policies
  99     static std::string date_to_string(date_type d)
 100     {
 101       typedef typename date_type::ymd_type ymd_type;
 102       if (d.is_not_a_date()) {
 103         return format_type::not_a_date();
 104       }
 105       if (d.is_neg_infinity()) {
 106         return format_type::neg_infinity();
 107       }
 108       if (d.is_pos_infinity()) {
 109         return format_type::pos_infinity();
 110       }
 111       ymd_type ymd = d.year_month_day();
 112       return ymd_formatter<ymd_type, format_type>::ymd_to_string(ymd);
 113     }
 114   };
 115
 116
 117 } } //namespace date_time
 118
 119
 120 #endif
 121