1 
2 #ifndef DATETIME_SPECIAL_VALUE_FORMATTER_HPP___
3 #define DATETIME_SPECIAL_VALUE_FORMATTER_HPP___
4 
5 /* Copyright (c) 2004 CrystalClear Software, Inc.
6  * Use, modification and distribution is subject to the
7  * Boost Software License, Version 1.0. (See accompanying
8  * file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
9  * Author: Jeff Garland
10  * $Date$
11  */
12 
13 #include <vector>
14 #include <string>
15 #include <iterator>
16 #include "boost/date_time/special_defs.hpp"
17 
18 namespace boost { namespace date_time {
19 
20 
21   //! Class that provides generic formmatting ostream formatting for special values
22   /*! This class provides for the formmating of special values to an output stream.
23    *  In particular, it produces strings for the values of negative and positive
24    *  infinity as well as not_a_date_time.
25    *
26    *  While not a facet, this class is used by the date and time facets for formatting
27    *  special value types.
28    *
29    */
30   template <class CharT, class OutItrT = std::ostreambuf_iterator<CharT, std::char_traits<CharT> > >
31   class special_values_formatter
32   {
33   public:
34     typedef std::basic_string<CharT> string_type;
35     typedef CharT                    char_type;
36     typedef std::vector<string_type> collection_type;
37     static const char_type default_special_value_names[3][17];
38 
39     //! Construct special values formatter using default strings.
40     /*! Default strings are not-a-date-time -infinity +infinity
41      */
special_values_formatter()42     special_values_formatter()
43     {
44       std::copy(&default_special_value_names[0],
45                 &default_special_value_names[3],
46                 std::back_inserter(m_special_value_names));
47     }
48 
49     //! Construct special values formatter from array of strings
50     /*! This constructor will take pair of iterators from an array of strings
51      *  that represent the special values and copy them for use in formatting
52      *  special values.
53      *@code
54      *  const char* const special_value_names[]={"nadt","-inf","+inf" };
55      *
56      *  special_value_formatter svf(&special_value_names[0], &special_value_names[3]);
57      *@endcode
58      */
special_values_formatter(const char_type * const * begin,const char_type * const * end)59     special_values_formatter(const char_type* const* begin, const char_type* const* end)
60     {
61       std::copy(begin, end, std::back_inserter(m_special_value_names));
62     }
special_values_formatter(typename collection_type::iterator beg,typename collection_type::iterator end)63     special_values_formatter(typename collection_type::iterator beg, typename collection_type::iterator end)
64     {
65       std::copy(beg, end, std::back_inserter(m_special_value_names));
66     }
67 
put_special(OutItrT next,const boost::date_time::special_values & value) const68     OutItrT put_special(OutItrT next,
69                         const boost::date_time::special_values& value) const
70     {
71 
72       unsigned int index = value;
73       if (index < m_special_value_names.size()) {
74         std::copy(m_special_value_names[index].begin(),
75                   m_special_value_names[index].end(),
76                   next);
77       }
78       return next;
79     }
80   protected:
81     collection_type m_special_value_names;
82   };
83 
84   //! Storage for the strings used to indicate special values
85   /* using c_strings to initialize these worked fine in testing, however,
86    * a project that compiled its objects separately, then linked in a separate
87    * step wound up with redefinition errors for the values in this array.
88    * Initializing individual characters eliminated this problem */
89   template <class CharT, class OutItrT>
90   const typename special_values_formatter<CharT, OutItrT>::char_type special_values_formatter<CharT, OutItrT>::default_special_value_names[3][17] = {
91     {'n','o','t','-','a','-','d','a','t','e','-','t','i','m','e'},
92     {'-','i','n','f','i','n','i','t','y'},
93     {'+','i','n','f','i','n','i','t','y'} };
94 
95  } } //namespace boost::date_time
96 
97 #endif
98