ex_flight.xml 6.9 KB

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  1. <?xml version="1.0" encoding="utf-8"?>
  2. <!DOCTYPE library PUBLIC "-//Boost//DTD BoostBook XML V1.0//EN"
  3. "../../../tools/boostbook/dtd/boostbook.dtd">
  4. <!-- Copyright (c) 2001-2005 CrystalClear Software, Inc.
  5. Subject to the Boost Software License, Version 1.0.
  6. (See accompanying file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
  7. -->
  8. <section id="date_time.examples.flight">
  9. <title>Flight Time Example</title>
  10. <para>This example shows a program that calculates the arrival time of a plane that flys from Phoenix to New York. During the flight New York shifts into daylight savings time (Phoenix doesn't because Arizona doesn't use dst).</para>
  11. <programlisting>
  12. <literal>
  13. <phrase role="preprocessor">#include</phrase><phrase role="string"> &quot;boost/date_time/local_time/local_time.hpp&quot;</phrase><phrase role="preprocessor">
  14. #include</phrase><phrase role="special"> &lt;</phrase><phrase role="identifier">iostream</phrase><phrase role="special">&gt;</phrase><phrase role="comment">
  15. /* This example shows a program that calculates the arrival time of a plane
  16. * that flys from Phoenix to New York. During the flight New York shifts
  17. * into daylight savings time (Phoenix doesn't because Arizona doesn't use
  18. * dst).
  19. *
  20. *
  21. */</phrase><phrase role="keyword">
  22. int</phrase><phrase role="identifier"> main</phrase><phrase role="special">()</phrase><phrase role="special">
  23. {</phrase><phrase role="keyword">
  24. using</phrase><phrase role="keyword"> namespace</phrase><phrase role="identifier"> boost</phrase><phrase role="special">::</phrase><phrase role="identifier">gregorian</phrase><phrase role="special">;</phrase><phrase role="keyword">
  25. using</phrase><phrase role="keyword"> namespace</phrase><phrase role="identifier"> boost</phrase><phrase role="special">::</phrase><phrase role="identifier">local_time</phrase><phrase role="special">;</phrase><phrase role="keyword">
  26. using</phrase><phrase role="keyword"> namespace</phrase><phrase role="identifier"> boost</phrase><phrase role="special">::</phrase><phrase role="identifier">posix_time</phrase><phrase role="special">;</phrase><phrase role="comment">
  27. //setup some timezones for creating and adjusting local times
  28. //This user editable file can be found in libs/date_time/data.
  29. </phrase><phrase role="identifier"> tz_database</phrase><phrase role="identifier"> tz_db</phrase><phrase role="special">;</phrase><phrase role="identifier">
  30. tz_db</phrase><phrase role="special">.</phrase><phrase role="identifier">load_from_file</phrase><phrase role="special">(</phrase><phrase role="string">&quot;date_time_zonespec.csv&quot;</phrase><phrase role="special">);</phrase><phrase role="identifier">
  31. time_zone_ptr</phrase><phrase role="identifier"> nyc_tz</phrase><phrase role="special"> =</phrase><phrase role="identifier"> tz_db</phrase><phrase role="special">.</phrase><phrase role="identifier">time_zone_from_region</phrase><phrase role="special">(</phrase><phrase role="string">&quot;America/New_York&quot;</phrase><phrase role="special">);</phrase><phrase role="comment">
  32. //Use a
  33. </phrase><phrase role="identifier"> time_zone_ptr</phrase><phrase role="identifier"> phx_tz</phrase><phrase role="special">(</phrase><phrase role="keyword">new</phrase><phrase role="identifier"> posix_time_zone</phrase><phrase role="special">(</phrase><phrase role="string">&quot;MST-07:00:00&quot;</phrase><phrase role="special">));</phrase><phrase role="comment">
  34. //local departure time in phoenix is 11 pm on april 2 2005
  35. // (ny changes to dst on apr 3 at 2 am)
  36. </phrase><phrase role="identifier"> local_date_time</phrase><phrase role="identifier"> phx_departure</phrase><phrase role="special">(</phrase><phrase role="identifier">date</phrase><phrase role="special">(</phrase><phrase role="number">2005</phrase><phrase role="special">,</phrase><phrase role="identifier"> Apr</phrase><phrase role="special">,</phrase><phrase role="number"> 2</phrase><phrase role="special">),</phrase><phrase role="identifier"> hours</phrase><phrase role="special">(</phrase><phrase role="number">23</phrase><phrase role="special">),</phrase><phrase role="identifier">
  37. phx_tz</phrase><phrase role="special">,</phrase><phrase role="identifier">
  38. local_date_time</phrase><phrase role="special">::</phrase><phrase role="identifier">NOT_DATE_TIME_ON_ERROR</phrase><phrase role="special">);</phrase><phrase role="identifier">
  39. time_duration</phrase><phrase role="identifier"> flight_length</phrase><phrase role="special"> =</phrase><phrase role="identifier"> hours</phrase><phrase role="special">(</phrase><phrase role="number">4</phrase><phrase role="special">)</phrase><phrase role="special"> +</phrase><phrase role="identifier"> minutes</phrase><phrase role="special">(</phrase><phrase role="number">30</phrase><phrase role="special">);</phrase><phrase role="identifier">
  40. local_date_time</phrase><phrase role="identifier"> phx_arrival</phrase><phrase role="special"> =</phrase><phrase role="identifier"> phx_departure</phrase><phrase role="special"> +</phrase><phrase role="identifier"> flight_length</phrase><phrase role="special">;</phrase><phrase role="identifier">
  41. local_date_time</phrase><phrase role="identifier"> nyc_arrival</phrase><phrase role="special"> =</phrase><phrase role="identifier"> phx_arrival</phrase><phrase role="special">.</phrase><phrase role="identifier">local_time_in</phrase><phrase role="special">(</phrase><phrase role="identifier">nyc_tz</phrase><phrase role="special">);</phrase><phrase role="identifier">
  42. std</phrase><phrase role="special">::</phrase><phrase role="identifier">cout</phrase><phrase role="special"> &lt;&lt;</phrase><phrase role="string"> &quot;departure phx time: &quot;</phrase><phrase role="special"> &lt;&lt;</phrase><phrase role="identifier"> phx_departure</phrase><phrase role="special"> &lt;&lt;</phrase><phrase role="identifier"> std</phrase><phrase role="special">::</phrase><phrase role="identifier">endl</phrase><phrase role="special">;</phrase><phrase role="identifier">
  43. std</phrase><phrase role="special">::</phrase><phrase role="identifier">cout</phrase><phrase role="special"> &lt;&lt;</phrase><phrase role="string"> &quot;arrival phx time: &quot;</phrase><phrase role="special"> &lt;&lt;</phrase><phrase role="identifier"> phx_arrival</phrase><phrase role="special"> &lt;&lt;</phrase><phrase role="identifier"> std</phrase><phrase role="special">::</phrase><phrase role="identifier">endl</phrase><phrase role="special">;</phrase><phrase role="identifier">
  44. std</phrase><phrase role="special">::</phrase><phrase role="identifier">cout</phrase><phrase role="special"> &lt;&lt;</phrase><phrase role="string"> &quot;arrival nyc time: &quot;</phrase><phrase role="special"> &lt;&lt;</phrase><phrase role="identifier"> nyc_arrival</phrase><phrase role="special"> &lt;&lt;</phrase><phrase role="identifier"> std</phrase><phrase role="special">::</phrase><phrase role="identifier">endl</phrase><phrase role="special">;</phrase><phrase role="special">
  45. }</phrase>
  46. </literal>
  47. </programlisting>
  48. </section>