boost/date_time/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: 2008-02-27 15:00:24 -0500 (Wed, 27 Feb 2008) $
*/
#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.
*
* <b>Template Parameters</b>
*
* <b>date_type</b>
*
* 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 ¤t_;};
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
/*
* <b>offset_functor</b>
*
* 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