Re: [Boost-users] [date_time] So how come there isn't a to_time_t helper func?

From: Jeff Garland (jeff_at_[hidden])
Date: 2006-05-04 08:31:05

Scott wrote:
> I noticed there's a from_time_t() helper function, but I need to convert
> from a ptime to a time_t.  Is this the proper way to do it?
> 
>   inline
>   std::time_t to_time_t(ptime t) 
>   {
>     ptime start(gregorian::date(1970,1,1));
>     time_duration dur = t - start;
>     return dur.seconds();
>   }
> 
> I'm also curious why such functionality isn't already available?

I suspect that it's a plot by the date_time author to keep people from 
using time_t ;-)

Seriously though, while your function will work for some times, there 
are issues:

1) ptime can represent dates prior to 1970-1-1 and after 2038 (or 
wherever the upper bound of time_t is).  Probably need an exception for 
these cases on the conversion.
2) ptime can represent times with less than 1 second resolution.  Maybe 
the function should round instead of truncating in case the time is 
2006-May-04 00:00:00.999999?

So if you're sure your application doesn't care about any of these 
issues than the function above should be fine.

Jeff