Boost date_time Part 1

The C++ _time library wraps the vagaries of time, date, and high resolution timing into a single header file, #include <boost/.hpp>. With all it does, it is relatively easy to use, and far easier than integrating your particular OS's date functions + low-resolution time function + high resolution time function, then accounting for time zones... The most difficult things about using the library are understanding how various time/date concepts are embodied in classes and the multiple-level namespaces.

Concepts Needed for date_time
Concept Class Example
Time Duration boost::posix_time::time_duration 3hr 40min 11s
Date boost::gregorian::date May 5, 2012
Absolute Time boost::posix_time May 5, 2012 23:53 UTC
Time Period boost::posix_time::time_period May 5, 2012 02:00 UTC thru May 12, 2012 18:00 UTC

Example C++ code demonstrating the different classes listed in the table above are show below. In each case, the first use of a function or member data is fully namespace qualified. I do this because I get frustrated with examples that presume the reader knows the namespace to use. To avoid visual clutter and verbosity, after the first use we take advantage of using namespace.

[crayon title="Example use of boost::posix_time::" url="2012/05/timeDurationExample.hpp" lang="cpp"/]
[crayon title="Example use of boost::gregorian::date" url="2012/05/dateExample.hpp" lang="cpp"/]
[crayon title="Example use of boost::posix_time::" url="2012/05/ptimeExample.hpp" lang="cpp"/]
[crayon title="Example use of boost::posix_time::ptime" url="2012/05/timePeriodExample.hpp" lang="cpp"/]

This post supplements two videos on the subject. The source file developed in the video is available below, as is the re-usable class Elapsed.hpp.

[youtube=http://www.youtube.com/watch?v=fxhOdIAKYhc]

[youtube=http://www.youtube.com/watch?v=wH2Fd_cchsM]

[crayon title="File date_time.cpp developed in the video" url="2012/05/date_time.cpp" lang="cpp"/]

[crayon title="Reusable class Elapsed.hpp developed in the video" url="2012/05/Elapsed.hpp" lang="cpp"/]

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