# print_holidays.cpp

This is an example of using functors to define a holiday schedule

    /*generate a set of dates using a collections of date generators
    Output looks like:
    Enter Year: 2002
    2002-Jan-01 [Tue]
    2002-Jan-21 [Mon]
    2002-Feb-12 [Tue]
    2002-Jul-04 [Thu]
    2002-Sep-02 [Mon]
    2002-Nov-28 [Thu]
    2002-Dec-25 [Wed]
    Number Holidays: 7
    */

    #include "boost/date_time/gregorian/gregorian.hpp"
    #include <algorithm>
    #include <functional>
    #include <vector>
    #include <iostream>
    #include <set>

    namespace std {
      //define an operator << for date so transform can call
      std::ostream&
      operator<<(std::ostream& os, const boost::gregorian::date& d)
      {
        os << boost::gregorian::to_simple_string(d);
        return os;
      }

    }

    void
    print_date(boost::gregorian::date d)
    {
      std::cout << d << " [" << d.
    }

    int
    main() {

      std::cout << "Enter Year: ";
      int
      std::cin >> year;

      using namespace boost::gregorian;

      //define a collection of holidays fixed by month and day
      std::vector<partial_date> holidays;
      holidays.push_back(partial_date(Jan,1)); //Western New Year
      holidays.push_back(partial_date(Jul,4)); //US Independence Day
      holidays.push_back(partial_date(Dec,25));//Christmas day

      //define a shorthand for the nkday function object
      typedef boost::date_time::nth_kday_of_month<date> nkday;
      //define a collection of nth kday holidays
      std::vector<nkday> more_holidays;
      more_holidays.push_back(nkday(nkday::first,  Monday,   Sep)); //US labor day
      more_holidays.push_back(nkday(nkday::third,  Monday,   Jan)); //MLK Day
      more_holidays.push_back(nkday(nkday::second, Tuesday,  Feb)); //Pres day
      more_holidays.push_back(nkday(nkday::fourth, Thursday, Nov)); //Thanksgiving

      typedef std::set<date> date_set;
      date_set all_holidays;

    #if (defined(BOOST_MSVC) && (_MSC_VER <= 1200))  // 1200 == VC++ 6.0
      std::cout << "Sorry, this example temporarily disabled on VC 6.\n"
             << "The std::transform isn't accepted by the compiler\n"
             << "So if you hack up the example without std::transform\n"
             << "it should work\n"
             << std::endl;

    #else

      //generate a set of concrete dates from the 'partial_date' holidays
      //by calling the get_date functions
      std::transform(holidays.begin(), holidays.end(),
               std::insert_iterator<date_set>(all_holidays, all_holidays.begin()),
               std::bind2nd(std::mem_fun_ref(&partial_date::get_date),
                         year));

      //Now add in the 'floating' holidays
      std::transform(more_holidays.begin(), more_holidays.end(),
               std::insert_iterator<date_set>(all_holidays, all_holidays.begin()),
               std::bind2nd(std::mem_fun_ref(&nkday::get_date),
                         year));

      //print the holidays to the screen
      std::for_each(all_holidays.begin(), all_holidays.end(), print_date);
      std::cout << "Number Holidays: " << all_holidays.size() << std::endl;

    #endif

    return 0;

    }