EVOLUTION-MANAGER

Edit File: date_iterator.hpp

#ifndef DATE_ITERATOR_HPP___
#define DATE_ITERATOR_HPP___

/* Copyright (c) 2002,2003 CrystalClear Software, Inc.
 * Use, modification and distribution is subject to the
 * Boost Software License, Version 1.0. (See accompanying
 * file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
 * Author: Jeff Garland, Bart Garst
 * $Date$
 */

#include <iterator>

namespace boost {
namespace date_time {
  //! An iterator over dates with varying resolution (day, week, month, year, etc)
  enum date_resolutions {day, week, months, year, decade, century, NumDateResolutions};

//! Base date iterator type
 /*! This class provides the skeleton for the creation of iterators.
 * New and interesting interators can be created by plugging in a new
 * function that derives the next value from the current state.
 * generation of various types of -based information.
 *
 * Template Parameters
 *
 * date_type
 *
 * The date_type is a concrete date_type. The date_type must
 * define a duration_type and a calendar_type.
 */
 template<class date_type>
 class date_itr_base {
 // works, but benefit unclear at the moment
 // class date_itr_base : public std::iterator<std::input_iterator_tag,
 // date_type, void, void, void>{
 public:
 typedef typename date_type::duration_type duration_type;
 typedef date_type value_type;
 typedef std::input_iterator_tag iterator_category;

date_itr_base(date_type d) : current_(d) {}
 virtual ~date_itr_base() {}
 date_itr_base& operator++()
 {
 current_ = current_ + get_offset(current_);
 return *this;
 }
 date_itr_base& operator--()
 {
 current_ = current_ + get_neg_offset(current_);
 return *this;
 }
 virtual duration_type get_offset(const date_type& current) const=0;
 virtual duration_type get_neg_offset(const date_type& current) const=0;
 date_type operator*() {return current_;}
 date_type* operator->() {return &current_;}
 bool operator< (const date_type& d) {return current_ < d;}
 bool operator<= (const date_type& d) {return current_ <= d;}
 bool operator> (const date_type& d) {return current_ > d;}
 bool operator>= (const date_type& d) {return current_ >= d;}
 bool operator== (const date_type& d) {return current_ == d;}
 bool operator!= (const date_type& d) {return current_ != d;}
 private:
 date_type current_;
 };

//! Overrides the base date iterator providing hook for functors
 /*
 * offset_functor
 *
 * The offset functor must define a get_offset function that takes the
 * current point in time and calculates and offset.
 *
 */
 template<class offset_functor, class date_type>
 class date_itr : public date_itr_base<date_type> {
 public:
 typedef typename date_type::duration_type duration_type;
 date_itr(date_type d, int factor=1) :
 date_itr_base<date_type>(d),
 of_(factor)
 {}
 private:
 virtual duration_type get_offset(const date_type& current) const
 {
 return of_.get_offset(current);
 }
 virtual duration_type get_neg_offset(const date_type& current) const
 {
 return of_.get_neg_offset(current);
 }
 offset_functor of_;
 };

} } //namespace date_time

#endif