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From: Philip Miller (pwmiller_at_[hidden])
Date: 2003-09-03 16:09:08

David Abrahams wrote:

> I'm trying to get a ptime relative to 1/1/1970, so I did:
> using namespace boost::date_time;
> ptime d;
> ...
> boost::posix_time::time_duration since_1970 = d - 1/Jan/1970;
> Error.
> Since it is a completely lossless conversion (like an upcast), I'd
> like to see boost::date -> boost::posix_time::ptime implicit
> conversions added.

Can you elaborate on the problem? I, too, am doing lots of conversions between
the boost::date_time library date, ptime, and duration instances with the
conventional unix/posix dawn of time, 1/1/1970. To my knowledge (perhaps in
ignorance), I have had no problems using constructs similar to

ptime time0( date(1970, 1, 1 ) );
ptime t1;
time_duration dt = t1 - time0;

Is the problem that you want to do this with date instances and not time

With regards to another posting you made, I also work to work with in sub-second
time precision and have had a problem understanding the nuances of clock
ticks/resolutions. As a simple user I have not had many (if any) problems getting
the library to do what I want, given that my assumption that
time_duration::fractional_seconds returns microseconds is correct. If/when this
assumption becomes invalid (i.e., date_time changes its internal representation
for msvc or I work on a platform that uses nanoseconds for fractional_seconds),
then I will be in trouble and have to fix a few places spots in my code. So, I
would like to see a standard time_duration accessor that returns microseconds
rather than the compile-time dependent fractional_seconds.


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