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## Class template date_generator_formatter

boost::date_time::date_generator_formatter — Formats date_generators for output.

## Synopsis

    // In header: <boost/date_time/date_generator_formatter.hpp>

    template<typename date_type, typename CharT,
             typename OutItrT = std::ostreambuf_iterator<CharT, std::char_traits<CharT> > >
    class date_generator_formatter {
    public:
      // types
      typedef partial_date< date_type >        partial_date_type;
      typedef nth_kday_of_month< date_type >   nth_kday_type;
      typedef first_kday_of_month< date_type > first_kday_type;
      typedef last_kday_of_month< date_type >  last_kday_type;
      typedef first_kday_after< date_type >    kday_after_type;
      typedef first_kday_before< date_type >   kday_before_type;
      typedef CharT                            char_type;
      typedef std::basic_string< char_type >   string_type;
      typedef std::vector< string_type >       collection_type;

      enum phrase_elements { first = =0, second, third, fourth, fifth, last,
                             before, after, of, number_of_phrase_elements };

      // construct/copy/destruct
      date_generator_formatter();
      date_generator_formatter(const string_type &, const string_type &,
                               const string_type &, const string_type &,
                               const string_type &, const string_type &,
                               const string_type &, const string_type &,
                               const string_type &);

      // public member functions
      void elements(const collection_type &, phrase_elements = first);
      template<typename facet_type>
        OutItrT put_partial_date(OutItrT, std::ios_base &, CharT,
                                 const partial_date_type &, const facet_type &) const;
      template<typename facet_type>
        OutItrT put_nth_kday(OutItrT, std::ios_base &, CharT,
                             const nth_kday_type &, const facet_type &) const;
      template<typename facet_type>
        OutItrT put_first_kday(OutItrT, std::ios_base &, CharT,
                               const first_kday_type &, const facet_type &) const;
      template<typename facet_type>
        OutItrT put_last_kday(OutItrT, std::ios_base &, CharT,
                              const last_kday_type &, const facet_type &) const;
      template<typename facet_type>
        OutItrT put_kday_before(OutItrT, std::ios_base &, CharT,
                                const kday_before_type &, const facet_type &) const;
      template<typename facet_type>
        OutItrT put_kday_after(OutItrT, std::ios_base &, CharT,
                               const kday_after_type &, const facet_type &) const;

      // private member functions
      OutItrT put_string(OutItrT, const string_type &) const;

      // public data members
      static const char_type first_string;
      static const char_type second_string;
      static const char_type third_string;
      static const char_type fourth_string;
      static const char_type fifth_string;
      static const char_type last_string;
      static const char_type before_string;
      static const char_type after_string;
      static const char_type of_string;
    };

## Description

Formatting of date_generators follows specific orders for the various types of date_generators.

- partial_date => "dd Month"

- nth_day_of_the_week_in_month => "nth weekday of month"

- first_day_of_the_week_in_month => "first weekday of month"

- last_day_of_the_week_in_month => "last weekday of month"

- first_day_of_the_week_after => "weekday after"

- first_day_of_the_week_before => "weekday before" While the order of the elements in these phrases cannot be changed, the elements themselves can be. Weekday and Month get their formats and names from the date_facet. The remaining elements are stored in the date_generator_formatter and can be customized upon construction or via a member function. The default elements are those shown in the examples above.

### `date_generator_formatter` public construct/copy/destruct

1.     date_generator_formatter();

   Default format elements used.

2.     date_generator_formatter(const string_type & first_str,
                                const string_type & second_str,
                                const string_type & third_str,
                                const string_type & fourth_str,
                                const string_type & fifth_str,
                                const string_type & last_str,
                                const string_type & before_str,
                                const string_type & after_str,
                                const string_type & of_str);

   Constructor that allows for a custom set of phrase elements.

### `date_generator_formatter` public member functions

1.     void elements(const collection_type & new_strings,
                     phrase_elements beg_pos = first);

   Replace the set of phrase elements with those contained in new_strings.

   The order of the strings in the given collection is important. They must follow:

   - first, second, third, fourth, fifth, last, before, after, of.

   It is not necessary to send in a complete set if only a few elements are to be replaced as long as the correct beg_pos is used.

   Ex: To keep the default first through fifth elements, but replace the rest with a collection of:

   - "final", "prior", "following", "in". The beg_pos of date_generator_formatter::last would be used.

2.     template<typename facet_type>
         OutItrT put_partial_date(OutItrT next, std::ios_base & a_ios, CharT a_fill,
                                  const partial_date_type & pd,
                                  const facet_type & facet) const;

   Put a `partial_date` => "dd Month".

3.     template<typename facet_type>
         OutItrT put_nth_kday(OutItrT next, std::ios_base & a_ios, CharT a_fill,
                              const nth_kday_type & nkd, const facet_type & facet) const;

   Put an nth_day_of_the_week_in_month => "nth weekday of month".

4.     template<typename facet_type>
         OutItrT put_first_kday(OutItrT next, std::ios_base & a_ios, CharT a_fill,
                                const first_kday_type & fkd,
                                const facet_type & facet) const;

   Put a first_day_of_the_week_in_month => "first weekday of month".

5.     template<typename facet_type>
         OutItrT put_last_kday(OutItrT next, std::ios_base & a_ios, CharT a_fill,
                               const last_kday_type & lkd, const facet_type & facet) const;

   Put a last_day_of_the_week_in_month => "last weekday of month".

6.     template<typename facet_type>
         OutItrT put_kday_before(OutItrT next, std::ios_base & a_ios, CharT a_fill,
                                 const kday_before_type & fkb,
                                 const facet_type & facet) const;

   Put a first_day_of_the_week_before => "weekday before".

7.     template<typename facet_type>
         OutItrT put_kday_after(OutItrT next, std::ios_base & a_ios, CharT a_fill,
                                const kday_after_type & fka,
                                const facet_type & facet) const;

   Put a first_day_of_the_week_after => "weekday after".

### `date_generator_formatter` private member functions

1.     OutItrT put_string(OutItrT next, const string_type & str) const;

   helper function to put the various member string into stream