...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Interval_sets
and
interval_maps
can be
filled and manipulated using set style operations such as union +=
, difference -=
and intersection &=
.
In this example man power a number of those operations are demonstrated in the process of calculation the available working times (man-power) of a company's employees accounting for weekends, holidays, sickness times and vacations.
// The next line includes <boost/gregorian/date.hpp> // and a few lines of adapter code. #include <boost/icl/gregorian.hpp> #include <iostream> #include <boost/icl/discrete_interval.hpp> #include <boost/icl/interval_map.hpp> using namespace std; using namespace boost::gregorian; using namespace boost::icl; // Function weekends returns the interval_set of weekends that are contained in // the date interval 'scope' interval_set<date> weekends(const discrete_interval<date>& scope) { interval_set<date> weekends; date cur_weekend_sat = first(scope) + days(days_until_weekday(first(scope), greg_weekday(Saturday))) - weeks(1); week_iterator week_iter(cur_weekend_sat); for(; week_iter <= last(scope); ++week_iter) weekends += discrete_interval<date>::right_open(*week_iter, *week_iter + days(2)); weekends &= scope; // cut off the surplus return weekends; } // The available working time for the employees of a company is calculated // for a period of 3 months accounting for weekends and holidays. // The available daily working time for the employees is calculated // using interval_sets and interval_maps demonstrating a number of // addition, subtraction and intersection operations. void man_power() { date someday = from_string("2008-08-01"); date thenday = someday + months(3); discrete_interval<date> scope = discrete_interval<date>::right_open(someday, thenday); // ------------------------------------------------------------------------ // (1) In a first step, the regular working times are computed for the // company within the given scope. From all available days, the weekends // and holidays have to be subtracted: interval_set<date> worktime(scope); // Subtract the weekends worktime -= weekends(scope); // Subtract holidays worktime -= from_string("2008-10-03"); //German reunification ;) // company holidays (fictitious ;) worktime -= discrete_interval<date>::closed(from_string("2008-08-18"), from_string("2008-08-22")); //------------------------------------------------------------------------- // (2) Now we calculate the individual work times for some employees //------------------------------------------------------------------------- // In the company works Claudia. // This is the map of her regular working times: interval_map<date,int> claudias_working_hours; // Claudia is working 8 hours a day. So the next statement says // that every day in the whole scope is mapped to 8 hours worktime. claudias_working_hours += make_pair(scope, 8); // But Claudia only works 8 hours on regular working days so we do // an intersection of the interval_map with the interval_set worktime: claudias_working_hours &= worktime; // Yet, in addition Claudia has her own absence times like discrete_interval<date> claudias_seminar (from_string("2008-09-16"), from_string("2008-09-24"), interval_bounds::closed()); discrete_interval<date> claudias_vacation(from_string("2008-08-01"), from_string("2008-08-14"), interval_bounds::closed()); interval_set<date> claudias_absence_times(claudias_seminar); claudias_absence_times += claudias_vacation; // All the absence times have to subtracted from the map of her working times claudias_working_hours -= claudias_absence_times; //------------------------------------------------------------------------- // Claudia's boss is Bodo. He only works part time. // This is the map of his regular working times: interval_map<date,int> bodos_working_hours; // Bodo is working 4 hours a day. bodos_working_hours += make_pair(scope, 4); // Bodo works only on regular working days bodos_working_hours &= worktime; // Bodos additional absence times discrete_interval<date> bodos_flu(from_string("2008-09-19"), from_string("2008-09-29"), interval_bounds::closed()); discrete_interval<date> bodos_vacation(from_string("2008-08-15"), from_string("2008-09-03"), interval_bounds::closed()); interval_set<date> bodos_absence_times(bodos_flu); bodos_absence_times += bodos_vacation; // All the absence times have to be subtracted from the map of his working times bodos_working_hours -= bodos_absence_times; //------------------------------------------------------------------------- // (3) Finally we want to calculate the available manpower of the company // for the selected time scope: This is done by adding up the employees // working time maps: interval_map<date,int> manpower; manpower += claudias_working_hours; manpower += bodos_working_hours; cout << first(scope) << " - " << last(scope) << " available man-power:" << endl; cout << "---------------------------------------------------------------\n"; for(interval_map<date,int>::iterator it = manpower.begin(); it != manpower.end(); it++) { cout << first(it->first) << " - " << last(it->first) << " -> " << it->second << endl; } } int main() { cout << ">>Interval Container Library: Sample man_power.cpp <<\n"; cout << "---------------------------------------------------------------\n"; man_power(); return 0; } // Program output: /* >>Interval Container Library: Sample man_power.cpp << --------------------------------------------------------------- 2008-Aug-01 - 2008-Oct-31 available man-power: --------------------------------------------------------------- 2008-Aug-01 - 2008-Aug-01 -> 4 2008-Aug-04 - 2008-Aug-08 -> 4 2008-Aug-11 - 2008-Aug-14 -> 4 2008-Aug-15 - 2008-Aug-15 -> 8 2008-Aug-25 - 2008-Aug-29 -> 8 2008-Sep-01 - 2008-Sep-03 -> 8 2008-Sep-04 - 2008-Sep-05 -> 12 2008-Sep-08 - 2008-Sep-12 -> 12 2008-Sep-15 - 2008-Sep-15 -> 12 2008-Sep-16 - 2008-Sep-18 -> 4 2008-Sep-25 - 2008-Sep-26 -> 8 2008-Sep-29 - 2008-Sep-29 -> 8 2008-Sep-30 - 2008-Oct-02 -> 12 2008-Oct-06 - 2008-Oct-10 -> 12 2008-Oct-13 - 2008-Oct-17 -> 12 2008-Oct-20 - 2008-Oct-24 -> 12 2008-Oct-27 - 2008-Oct-31 -> 12 */