--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/imgtools/imglib/boostlibrary/boost/date_time/period.hpp Tue Oct 27 16:36:35 2009 +0000
@@ -0,0 +1,377 @@
+#ifndef DATE_TIME_PERIOD_HPP___
+#define DATE_TIME_PERIOD_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) $
+ */
+
+/*! \file period.hpp
+ This file contain the implementation of the period abstraction. This is
+ basically the same idea as a range. Although this class is intended for
+ use in the time library, it is pretty close to general enough for other
+ numeric uses.
+
+*/
+
+#include "boost/operators.hpp"
+
+
+namespace boost {
+namespace date_time {
+ //!Provides generalized period type useful in date-time systems
+ /*!This template uses a class to represent a time point within the period
+ and another class to represent a duration. As a result, this class is
+ not appropriate for use when the number and duration representation
+ are the same (eg: in the regular number domain).
+
+ A period can be specified by providing either the begining point and
+ a duration or the begining point and the end point( end is NOT part
+ of the period but 1 unit past it. A period will be "invalid" if either
+ end_point <= begin_point or the given duration is <= 0. Any valid period
+ will return false for is_null().
+
+ Zero length periods are also considered invalid. Zero length periods are
+ periods where the begining and end points are the same, or, the given
+ duration is zero. For a zero length period, the last point will be one
+ unit less than the begining point.
+
+ In the case that the begin and last are the same, the period has a
+ length of one unit.
+
+ The best way to handle periods is usually to provide a begining point and
+ a duration. So, day1 + 7 days is a week period which includes all of the
+ first day and 6 more days (eg: Sun to Sat).
+
+ */
+ template<class point_rep, class duration_rep>
+ class period : private
+ boost::less_than_comparable<period<point_rep, duration_rep>
+ , boost::equality_comparable< period<point_rep, duration_rep>
+ > >
+ {
+ public:
+ typedef point_rep point_type;
+ typedef duration_rep duration_type;
+
+ period(point_rep first_point, point_rep end_point);
+ period(point_rep first_point, duration_rep len);
+ point_rep begin() const;
+ point_rep end() const;
+ point_rep last() const;
+ duration_rep length() const;
+ bool is_null() const;
+ bool operator==(const period& rhs) const;
+ bool operator<(const period& rhs) const;
+ void shift(const duration_rep& d);
+ void expand(const duration_rep& d);
+ bool contains(const point_rep& point) const;
+ bool contains(const period& other) const;
+ bool intersects(const period& other) const;
+ bool is_adjacent(const period& other) const;
+ bool is_before(const point_rep& point) const;
+ bool is_after(const point_rep& point) const;
+ period intersection(const period& other) const;
+ period merge(const period& other) const;
+ period span(const period& other) const;
+ private:
+ point_rep begin_;
+ point_rep last_;
+ };
+
+ //! create a period from begin to last eg: [begin,end)
+ /*! If end <= begin then the period will be invalid
+ */
+ template<class point_rep, class duration_rep>
+ inline
+ period<point_rep,duration_rep>::period(point_rep first_point,
+ point_rep end_point) :
+ begin_(first_point),
+ last_(end_point - duration_rep::unit())
+ {}
+
+ //! create a period as [begin, begin+len)
+ /*! If len is <= 0 then the period will be invalid
+ */
+ template<class point_rep, class duration_rep>
+ inline
+ period<point_rep,duration_rep>::period(point_rep first_point, duration_rep len) :
+ begin_(first_point),
+ last_(first_point + len-duration_rep::unit())
+ { }
+
+
+ //! Return the first element in the period
+ template<class point_rep, class duration_rep>
+ inline
+ point_rep period<point_rep,duration_rep>::begin() const
+ {
+ return begin_;
+ }
+
+ //! Return one past the last element
+ template<class point_rep, class duration_rep>
+ inline
+ point_rep period<point_rep,duration_rep>::end() const
+ {
+ return last_ + duration_rep::unit();
+ }
+
+ //! Return the last item in the period
+ template<class point_rep, class duration_rep>
+ inline
+ point_rep period<point_rep,duration_rep>::last() const
+ {
+ return last_;
+ }
+
+ //! True if period is ill formed (length is zero or less)
+ template<class point_rep, class duration_rep>
+ inline
+ bool period<point_rep,duration_rep>::is_null() const
+ {
+ return end() <= begin_;
+ }
+
+ //! Return the length of the period
+ template<class point_rep, class duration_rep>
+ inline
+ duration_rep period<point_rep,duration_rep>::length() const
+ {
+ if(last_ < begin_){ // invalid period
+ return last_+duration_rep::unit() - begin_;
+ }
+ else{
+ return end() - begin_; // normal case
+ }
+ }
+
+ //! Equality operator
+ template<class point_rep, class duration_rep>
+ inline
+ bool period<point_rep,duration_rep>::operator==(const period& rhs) const
+ {
+ return ((begin_ == rhs.begin_) &&
+ (last_ == rhs.last_));
+ }
+
+ //! Strict as defined by rhs.last <= lhs.last
+ template<class point_rep, class duration_rep>
+ inline
+ bool period<point_rep,duration_rep>::operator<(const period& rhs) const
+ {
+ return (last_ < rhs.begin_);
+ }
+
+
+ //! Shift the start and end by the specified amount
+ template<class point_rep, class duration_rep>
+ inline
+ void period<point_rep,duration_rep>::shift(const duration_rep& d)
+ {
+ begin_ = begin_ + d;
+ last_ = last_ + d;
+ }
+
+ /** Expands the size of the period by the duration on both ends.
+ *
+ *So before expand
+ *@code
+ *
+ * [-------]
+ * ^ ^ ^ ^ ^ ^ ^
+ * 1 2 3 4 5 6 7
+ *
+ *@endcode
+ * After expand(2)
+ *@code
+ *
+ * [----------------------]
+ * ^ ^ ^ ^ ^ ^ ^
+ * 1 2 3 4 5 6 7
+ *
+ *@endcode
+ */
+ template<class point_rep, class duration_rep>
+ inline
+ void period<point_rep,duration_rep>::expand(const duration_rep& d)
+ {
+ begin_ = begin_ - d;
+ last_ = last_ + d;
+ }
+
+ //! True if the point is inside the period, zero length periods contain no points
+ template<class point_rep, class duration_rep>
+ inline
+ bool period<point_rep,duration_rep>::contains(const point_rep& point) const
+ {
+ return ((point >= begin_) &&
+ (point <= last_));
+ }
+
+
+ //! True if this period fully contains (or equals) the other period
+ template<class point_rep, class duration_rep>
+ inline
+ bool period<point_rep,duration_rep>::contains(const period<point_rep,duration_rep>& other) const
+ {
+ return ((begin_ <= other.begin_) && (last_ >= other.last_));
+ }
+
+
+ //! True if periods are next to each other without a gap.
+ /* In the example below, p1 and p2 are adjacent, but p3 is not adjacent
+ * with either of p1 or p2.
+ *@code
+ * [-p1-)
+ * [-p2-)
+ * [-p3-)
+ *@endcode
+ */
+ template<class point_rep, class duration_rep>
+ inline
+ bool
+ period<point_rep,duration_rep>::is_adjacent(const period<point_rep,duration_rep>& other) const
+ {
+ return (other.begin() == end() ||
+ begin_ == other.end());
+ }
+
+
+ //! True if all of the period is prior or t < start
+ /* In the example below only point 1 would evaluate to true.
+ *@code
+ * [---------])
+ * ^ ^ ^ ^ ^
+ * 1 2 3 4 5
+ *
+ *@endcode
+ */
+ template<class point_rep, class duration_rep>
+ inline
+ bool
+ period<point_rep,duration_rep>::is_after(const point_rep& t) const
+ {
+ if (is_null())
+ {
+ return false; //null period isn't after
+ }
+
+ return t < begin_;
+ }
+
+ //! True if all of the period is prior to the passed point or end <= t
+ /* In the example below points 4 and 5 return true.
+ *@code
+ * [---------])
+ * ^ ^ ^ ^ ^
+ * 1 2 3 4 5
+ *
+ *@endcode
+ */
+ template<class point_rep, class duration_rep>
+ inline
+ bool
+ period<point_rep,duration_rep>::is_before(const point_rep& t) const
+ {
+ if (is_null())
+ {
+ return false; //null period isn't before anything
+ }
+
+ return last_ < t;
+ }
+
+
+ //! True if the periods overlap in any way
+ /* In the example below p1 intersects with p2, p4, and p6.
+ *@code
+ * [---p1---)
+ * [---p2---)
+ * [---p3---)
+ * [---p4---)
+ * [-p5-)
+ * [-p6-)
+ *@endcode
+ */
+ template<class point_rep, class duration_rep>
+ inline
+ bool period<point_rep,duration_rep>::intersects(const period<point_rep,duration_rep>& other) const
+ {
+ return ( contains(other.begin_) ||
+ other.contains(begin_) ||
+ ((other.begin_ < begin_) && (other.last_ >= begin_)));
+ }
+
+ //! Returns the period of intersection or invalid range no intersection
+ template<class point_rep, class duration_rep>
+ inline
+ period<point_rep,duration_rep>
+ period<point_rep,duration_rep>::intersection(const period<point_rep,duration_rep>& other) const
+ {
+ if (begin_ > other.begin_) {
+ if (last_ <= other.last_) { //case2
+ return *this;
+ }
+ //case 1
+ return period<point_rep,duration_rep>(begin_, other.end());
+ }
+ else {
+ if (last_ <= other.last_) { //case3
+ return period<point_rep,duration_rep>(other.begin_, this->end());
+ }
+ //case4
+ return other;
+ }
+ //unreachable
+ }
+
+ //! Returns the union of intersecting periods -- or null period
+ /*!
+ */
+ template<class point_rep, class duration_rep>
+ inline
+ period<point_rep,duration_rep>
+ period<point_rep,duration_rep>::merge(const period<point_rep,duration_rep>& other) const
+ {
+ if (this->intersects(other)) {
+ if (begin_ < other.begin_) {
+ return period<point_rep,duration_rep>(begin_, last_ > other.last_ ? this->end() : other.end());
+ }
+
+ return period<point_rep,duration_rep>(other.begin_, last_ > other.last_ ? this->end() : other.end());
+
+ }
+ return period<point_rep,duration_rep>(begin_,begin_); // no intersect return null
+ }
+
+ //! Combine two periods with earliest start and latest end.
+ /*! Combines two periods and any gap between them such that
+ * start = min(p1.start, p2.start)
+ * end = max(p1.end , p2.end)
+ *@code
+ * [---p1---)
+ * [---p2---)
+ * result:
+ * [-----------p3----------)
+ *@endcode
+ */
+ template<class point_rep, class duration_rep>
+ inline
+ period<point_rep,duration_rep>
+ period<point_rep,duration_rep>::span(const period<point_rep,duration_rep>& other) const
+ {
+ point_rep start((begin_ < other.begin_) ? begin() : other.begin());
+ point_rep newend((last_ < other.last_) ? other.end() : this->end());
+ return period<point_rep,duration_rep>(start, newend);
+ }
+
+
+} } //namespace date_time
+
+
+
+#endif