1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/os/ossrv/ossrv_pub/boost_apis/boost/date_time/period.hpp Fri Jun 15 03:10:57 2012 +0200
1.3 @@ -0,0 +1,352 @@
1.4 +#ifndef DATE_TIME_PERIOD_HPP___
1.5 +#define DATE_TIME_PERIOD_HPP___
1.6 +
1.7 +/* Copyright (c) 2002,2003 CrystalClear Software, Inc.
1.8 + *
1.9 + * Distributed under the Boost Software License, Version 1.0.
1.10 + * (See accompanying file LICENSE_1_0.txt or copy at
1.11 + * http://www.boost.org/LICENSE_1_0.txt)
1.12 + *
1.13 + *
1.14 + * Author: Jeff Garland, Bart Garst
1.15 + * $Date: 2006/07/17 03:56:05 $
1.16 + */
1.17 +
1.18 +/*! \file period.hpp
1.19 + This file contain the implementation of the period abstraction. This is
1.20 + basically the same idea as a range. Although this class is intended for
1.21 + use in the time library, it is pretty close to general enough for other
1.22 + numeric uses.
1.23 +
1.24 +*/
1.25 +
1.26 +#include "boost/operators.hpp"
1.27 +
1.28 +
1.29 +namespace boost {
1.30 +namespace date_time {
1.31 + //!Provides generalized period type useful in date-time systems
1.32 + /*!This template uses a class to represent a time point within the period
1.33 + and another class to represent a duration. As a result, this class is
1.34 + not appropriate for use when the number and duration representation
1.35 + are the same (eg: in the regular number domain).
1.36 +
1.37 + A period can be specified by providing either the begining point and
1.38 + a duration or the begining point and the end point( end is NOT part
1.39 + of the period but 1 unit past it. A period will be "invalid" if either
1.40 + end_point <= begin_point or the given duration is <= 0. Any valid period
1.41 + will return false for is_null().
1.42 +
1.43 + Zero length periods are also considered invalid. Zero length periods are
1.44 + periods where the begining and end points are the same, or, the given
1.45 + duration is zero. For a zero length period, the last point will be one
1.46 + unit less than the begining point.
1.47 +
1.48 + In the case that the begin and last are the same, the period has a
1.49 + length of one unit.
1.50 +
1.51 + The best way to handle periods is usually to provide a begining point and
1.52 + a duration. So, day1 + 7 days is a week period which includes all of the
1.53 + first day and 6 more days (eg: Sun to Sat).
1.54 +
1.55 + */
1.56 + template<class point_rep, class duration_rep>
1.57 + class period : private
1.58 + boost::less_than_comparable<period<point_rep, duration_rep>
1.59 + , boost::equality_comparable< period<point_rep, duration_rep>
1.60 + > >
1.61 + {
1.62 + public:
1.63 + typedef point_rep point_type;
1.64 + typedef duration_rep duration_type;
1.65 +
1.66 + period(point_rep first_point, point_rep end_point);
1.67 + period(point_rep first_point, duration_rep len);
1.68 + point_rep begin() const;
1.69 + point_rep end() const;
1.70 + point_rep last() const;
1.71 + duration_rep length() const;
1.72 + bool is_null() const;
1.73 + bool operator==(const period& rhs) const;
1.74 + bool operator<(const period& rhs) const;
1.75 + void shift(const duration_rep& d);
1.76 + bool contains(const point_rep& point) const;
1.77 + bool contains(const period& other) const;
1.78 + bool intersects(const period& other) const;
1.79 + bool is_adjacent(const period& other) const;
1.80 + bool is_before(const point_rep& point) const;
1.81 + bool is_after(const point_rep& point) const;
1.82 + period intersection(const period& other) const;
1.83 + period merge(const period& other) const;
1.84 + period span(const period& other) const;
1.85 + private:
1.86 + point_rep begin_;
1.87 + point_rep last_;
1.88 + };
1.89 +
1.90 + //! create a period from begin to last eg: [begin,end)
1.91 + /*! If end <= begin then the period will be invalid
1.92 + */
1.93 + template<class point_rep, class duration_rep>
1.94 + inline
1.95 + period<point_rep,duration_rep>::period(point_rep first_point,
1.96 + point_rep end_point) :
1.97 + begin_(first_point),
1.98 + last_(end_point - duration_rep::unit())
1.99 + {}
1.100 +
1.101 + //! create a period as [begin, begin+len)
1.102 + /*! If len is <= 0 then the period will be invalid
1.103 + */
1.104 + template<class point_rep, class duration_rep>
1.105 + inline
1.106 + period<point_rep,duration_rep>::period(point_rep first_point, duration_rep len) :
1.107 + begin_(first_point),
1.108 + last_(first_point + len-duration_rep::unit())
1.109 + { }
1.110 +
1.111 +
1.112 + //! Return the first element in the period
1.113 + template<class point_rep, class duration_rep>
1.114 + inline
1.115 + point_rep period<point_rep,duration_rep>::begin() const
1.116 + {
1.117 + return begin_;
1.118 + }
1.119 +
1.120 + //! Return one past the last element
1.121 + template<class point_rep, class duration_rep>
1.122 + inline
1.123 + point_rep period<point_rep,duration_rep>::end() const
1.124 + {
1.125 + return last_ + duration_rep::unit();
1.126 + }
1.127 +
1.128 + //! Return the last item in the period
1.129 + template<class point_rep, class duration_rep>
1.130 + inline
1.131 + point_rep period<point_rep,duration_rep>::last() const
1.132 + {
1.133 + return last_;
1.134 + }
1.135 +
1.136 + //! True if period is ill formed (length is zero or less)
1.137 + template<class point_rep, class duration_rep>
1.138 + inline
1.139 + bool period<point_rep,duration_rep>::is_null() const
1.140 + {
1.141 + return end() <= begin_;
1.142 + }
1.143 +
1.144 + //! Return the length of the period
1.145 + template<class point_rep, class duration_rep>
1.146 + inline
1.147 + duration_rep period<point_rep,duration_rep>::length() const
1.148 + {
1.149 + if(last_ < begin_){ // invalid period
1.150 + return last_+duration_rep::unit() - begin_;
1.151 + }
1.152 + else{
1.153 + return end() - begin_; // normal case
1.154 + }
1.155 + }
1.156 +
1.157 + //! Equality operator
1.158 + template<class point_rep, class duration_rep>
1.159 + inline
1.160 + bool period<point_rep,duration_rep>::operator==(const period& rhs) const
1.161 + {
1.162 + return ((begin_ == rhs.begin_) &&
1.163 + (last_ == rhs.last_));
1.164 + }
1.165 +
1.166 + //! Strict as defined by rhs.last <= lhs.last
1.167 + template<class point_rep, class duration_rep>
1.168 + inline
1.169 + bool period<point_rep,duration_rep>::operator<(const period& rhs) const
1.170 + {
1.171 + return (last_ < rhs.begin_);
1.172 + }
1.173 +
1.174 +
1.175 + //! Shift the start and end by the specified amount
1.176 + template<class point_rep, class duration_rep>
1.177 + inline
1.178 + void period<point_rep,duration_rep>::shift(const duration_rep& d)
1.179 + {
1.180 + begin_ = begin_ + d;
1.181 + last_ = last_ + d;
1.182 + }
1.183 +
1.184 + //! True if the point is inside the period, zero length periods contain no points
1.185 + template<class point_rep, class duration_rep>
1.186 + inline
1.187 + bool period<point_rep,duration_rep>::contains(const point_rep& point) const
1.188 + {
1.189 + return ((point >= begin_) &&
1.190 + (point <= last_));
1.191 + }
1.192 +
1.193 +
1.194 + //! True if this period fully contains (or equals) the other period
1.195 + template<class point_rep, class duration_rep>
1.196 + inline
1.197 + bool period<point_rep,duration_rep>::contains(const period<point_rep,duration_rep>& other) const
1.198 + {
1.199 + return ((begin_ <= other.begin_) && (last_ >= other.last_));
1.200 + }
1.201 +
1.202 +
1.203 + //! True if periods are next to each other without a gap.
1.204 + /* In the example below, p1 and p2 are adjacent, but p3 is not adjacent
1.205 + * with either of p1 or p2.
1.206 + *@code
1.207 + * [-p1-)
1.208 + * [-p2-)
1.209 + * [-p3-)
1.210 + *@endcode
1.211 + */
1.212 + template<class point_rep, class duration_rep>
1.213 + inline
1.214 + bool
1.215 + period<point_rep,duration_rep>::is_adjacent(const period<point_rep,duration_rep>& other) const
1.216 + {
1.217 + return (other.begin() == end() ||
1.218 + begin_ == other.end());
1.219 + }
1.220 +
1.221 +
1.222 + //! True if all of the period is prior or t < start
1.223 + /* In the example below only point 1 would evaluate to true.
1.224 + *@code
1.225 + * [---------])
1.226 + * ^ ^ ^ ^ ^
1.227 + * 1 2 3 4 5
1.228 + *
1.229 + *@endcode
1.230 + */
1.231 + template<class point_rep, class duration_rep>
1.232 + inline
1.233 + bool
1.234 + period<point_rep,duration_rep>::is_after(const point_rep& t) const
1.235 + {
1.236 + if (is_null())
1.237 + {
1.238 + return false; //null period isn't after
1.239 + }
1.240 +
1.241 + return t < begin_;
1.242 + }
1.243 +
1.244 + //! True if all of the period is prior to the passed point or end <= t
1.245 + /* In the example below points 4 and 5 return true.
1.246 + *@code
1.247 + * [---------])
1.248 + * ^ ^ ^ ^ ^
1.249 + * 1 2 3 4 5
1.250 + *
1.251 + *@endcode
1.252 + */
1.253 + template<class point_rep, class duration_rep>
1.254 + inline
1.255 + bool
1.256 + period<point_rep,duration_rep>::is_before(const point_rep& t) const
1.257 + {
1.258 + if (is_null())
1.259 + {
1.260 + return false; //null period isn't before anything
1.261 + }
1.262 +
1.263 + return last_ < t;
1.264 + }
1.265 +
1.266 +
1.267 + //! True if the periods overlap in any way
1.268 + /* In the example below p1 intersects with p2, p4, and p6.
1.269 + *@code
1.270 + * [---p1---)
1.271 + * [---p2---)
1.272 + * [---p3---)
1.273 + * [---p4---)
1.274 + * [-p5-)
1.275 + * [-p6-)
1.276 + *@endcode
1.277 + */
1.278 + template<class point_rep, class duration_rep>
1.279 + inline
1.280 + bool period<point_rep,duration_rep>::intersects(const period<point_rep,duration_rep>& other) const
1.281 + {
1.282 + return ( contains(other.begin_) ||
1.283 + other.contains(begin_) ||
1.284 + ((other.begin_ < begin_) && (other.last_ >= begin_)));
1.285 + }
1.286 +
1.287 + //! Returns the period of intersection or invalid range no intersection
1.288 + template<class point_rep, class duration_rep>
1.289 + inline
1.290 + period<point_rep,duration_rep>
1.291 + period<point_rep,duration_rep>::intersection(const period<point_rep,duration_rep>& other) const
1.292 + {
1.293 + if (begin_ > other.begin_) {
1.294 + if (last_ <= other.last_) { //case2
1.295 + return *this;
1.296 + }
1.297 + //case 1
1.298 + return period<point_rep,duration_rep>(begin_, other.end());
1.299 + }
1.300 + else {
1.301 + if (last_ <= other.last_) { //case3
1.302 + return period<point_rep,duration_rep>(other.begin_, this->end());
1.303 + }
1.304 + //case4
1.305 + return other;
1.306 + }
1.307 + //unreachable
1.308 + }
1.309 +
1.310 + //! Returns the union of intersecting periods -- or null period
1.311 + /*!
1.312 + */
1.313 + template<class point_rep, class duration_rep>
1.314 + inline
1.315 + period<point_rep,duration_rep>
1.316 + period<point_rep,duration_rep>::merge(const period<point_rep,duration_rep>& other) const
1.317 + {
1.318 + if (this->intersects(other)) {
1.319 + if (begin_ < other.begin_) {
1.320 + return period<point_rep,duration_rep>(begin_, last_ > other.last_ ? this->end() : other.end());
1.321 + }
1.322 +
1.323 + return period<point_rep,duration_rep>(other.begin_, last_ > other.last_ ? this->end() : other.end());
1.324 +
1.325 + }
1.326 + return period<point_rep,duration_rep>(begin_,begin_); // no intersect return null
1.327 + }
1.328 +
1.329 + //! Combine two periods with earliest start and latest end.
1.330 + /*! Combines two periods and any gap between them such that
1.331 + * start = minimum(p1.start, p2.start)
1.332 + * end = maximum(p1.end , p2.end)
1.333 + *@code
1.334 + * [---p1---)
1.335 + * [---p2---)
1.336 + * result:
1.337 + * [-----------p3----------)
1.338 + *@endcode
1.339 + */
1.340 + template<class point_rep, class duration_rep>
1.341 + inline
1.342 + period<point_rep,duration_rep>
1.343 + period<point_rep,duration_rep>::span(const period<point_rep,duration_rep>& other) const
1.344 + {
1.345 + point_rep start((begin_ < other.begin_) ? begin() : other.begin());
1.346 + point_rep newend((last_ < other.last_) ? other.end() : this->end());
1.347 + return period<point_rep,duration_rep>(start, newend);
1.348 + }
1.349 +
1.350 +
1.351 +} } //namespace date_time
1.352 +
1.353 +
1.354 +
1.355 +#endif