status changed; resolution set

Marshall Clow — Sat, 15 Mar 2014 15:42:07 GMT

status new → closed
resolution → invalid

Here's my take on the code in days_before_weekday:

1: Calculates a number in the range 0 .. 6 for the next time the specified day of the week rolls around. Note that asking for Tuesday on Tuesday gives you 0.

2: If we got a number > 0, then we're looking into the future. Set the wks variable to 7.

3: Step wks days into the future, and then subtract off the number of days we calculated in step 1.

Note that the comment at the end of the routine explicitly says that this function can return zero (i.e, zero days from d). I don't see a bug in this code (though I would be tempted to write it like this - warning: untested code):

    typedef typename date_type::duration_type duration_type;
    duration_type dd(wd.as_number() - d.day_of_week().as_number()); // 1
    return dd ? duration_type(7) - dd ? 0;

I don't think there's a bug in this code. The behavior "return 0 when asking for last Tuesday on Tuesday" is quite deliberate. Whether or not that should be the behavior is a different question, and that's a discussion that should be had on the boost mailing list.

I'll take a look at the documentation; see what the best place to add a note is. Closing this as "not a bug". If you disagree, please re-open it.

Boost C++ Libraries: Ticket #5753: previous_weekday() returns the very same day

status changed; resolution set