[boost] Re: Date-Time

From: David Abrahams (dave_at_[hidden])
Date: 2004-04-17 12:38:36

"Janusz Piwowarski" <jpiw_at_[hidden]> writes:

> Rob Stewart writes:
>  
>> That makes the result of the expression quite explicit.  I can't
>> see any problems with that approach.  I'd expect an exception if
>> the resulting month doesn't have the requested day.  OTOH, if
>> date's ctor were to take an extra argument, or if there was a
>> date factory function supplying the different behavior, you could
>> specify that you want clipping to the last day of the designated
>> month:
>> 
>>    date(d.month() + 2 * months, d.day(), clip_to_eom)
>>    make_date_clipped_to_end_of_month(d.month() + 2 * months,
>>       d.day())
>> 
>
> IMHO, simple date wrappers can give more readability:
>
>     d.allow_clipping_to_eom() + 2*months;
>     d.disallow_clipping_to_eom() + 2*months;
>
> or 
>
>     allow_clipping_to_eom(d) + 2*months;
>     disallow_clipping_to_eom(d) + 2*months;
>
> where adding months to date directly isn't allowed.

That said, I'd really like to de-emphasize the importance of this
clipping behavior.  We already have a plausible way to represent a
particular month, e.g. Feb/2003.  I'd like to be able to write:

    30/(Feb/2003 + 3*month)

To get 30/May/2003.

Cheers,

-- 
Dave Abrahams
Boost Consulting
http://www.boost-consulting.com