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- <?xml version="1.0" encoding="utf-8"?>
- <!DOCTYPE library PUBLIC "-//Boost//DTD BoostBook XML V1.0//EN"
- "../../../tools/boostbook/dtd/boostbook.dtd">
- <!-- Copyright (c) 2001-2005 CrystalClear Software, Inc.
- 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)
- -->
- <section id="date_time.design_goals">
- <title>Design Goals</title>
- <informaltable frame="all">
- <tgroup cols="2">
- <thead>
- <row>
- <entry valign="top" morerows="1">Category</entry>
- <entry>Description</entry>
- </row>
- <row>
- <entry>Functions</entry>
- </row>
- </thead>
- <tbody>
- <row>
- <entry valign="top" morerows="1">Interfaces</entry>
- <entry>Provide concrete classes for manipulation of dates and times</entry>
- </row>
- <row>
- <entry>
- <itemizedlist mark="bullet">
- <listitem>date, time, date_duration, time_duration, date_period, time_period, etc</listitem>
- <listitem>support for infinity - positive infinity, negative infinity</listitem>
- <listitem>iterators over time and date ranges</listitem>
- <listitem>allow date and time implementations to be separate as much as possible</listitem>
- </itemizedlist>
- </entry>
- </row>
- <row>
- <entry valign="top" morerows="1">Calculation</entry>
- <entry>Provide a basis for performing efficient time calculations </entry>
- </row>
- <row>
- <entry>
- <itemizedlist mark="bullet">
- <listitem>days between dates </listitem>
- <listitem>durations of times </listitem>
- <listitem>durations of dates and times together </listitem>
- </itemizedlist>
- </entry>
- </row>
- <row>
- <entry valign="top" morerows="1">Representation Flexibility</entry>
- <entry>Provide the maximum possible reusability and flexibility</entry>
- </row>
- <row>
- <entry>
- <itemizedlist mark="bullet">
- <listitem>traits based customization of internal representations for size versus resolution control</listitem>
- <listitem>Allowing the use of different epochs and resolution (eg: seconds versus microseconds, dates starting at the year 2000 versus dates starting in 1700)</listitem>
- <listitem>Options for configuring unique calendar representations (Gregorian + others)</listitem>
- <listitem>the use of Julian Day number and the conversion between this and the Gregorian/Julian calendar date</listitem>
- <listitem>Allow for flexible adjustments including leap seconds</listitem>
- </itemizedlist>
- </entry>
- </row>
- <row>
- <entry valign="top" morerows="1">Date Calculations</entry>
- <entry>Provide tools for date calculations</entry>
- </row>
- <row>
- <entry>
- <itemizedlist mark="bullet">
- <listitem>provide basis for calculation of complex event specs like holidays</listitem>
- <listitem>calendar to calendar conversions</listitem>
- <listitem>provide for ability to extend to new calendar systems</listitem>
- </itemizedlist>
- </entry>
- </row>
- <row>
- <entry valign="top" morerows="1">Time Calculations</entry>
- <entry>Provide concrete classes for manipulation of time</entry>
- </row>
- <row>
- <entry>
- <itemizedlist mark="bullet">
- <listitem>provide the ability to handle cross time-zone issues</listitem>
- <listitem>provide adjustments for daylight savings time (summer time)</listitem>
- </itemizedlist>
- </entry>
- </row>
- <row>
- <entry valign="top" morerows="1">Clock Interfaces</entry>
- <entry>Provide classes for retrieving time current time</entry>
- </row>
- <row>
- <entry>
- <itemizedlist mark="bullet">
- <listitem>access to a network / high resolution time sources </listitem>
- <listitem>retrieving the current date time information to populate classes </listitem>
- </itemizedlist>
- </entry>
- </row>
-
- <row>
- <entry valign="top" morerows="1">I/O Interfaces</entry>
- <entry>Provide input and output for time including</entry>
- </row>
- <row>
- <entry>
- <itemizedlist mark="bullet">
- <listitem>multi-lingual support </listitem>
- <listitem>provide ISO8601 compliant time facet </listitem>
- <listitem>use I/O facets for different local behavior </listitem>
- </itemizedlist>
- </entry>
- </row>
- </tbody>
- </tgroup>
- </informaltable>
- </section>
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