Boost logo

Boost :

From: Jeff Garland (jeff_at_[hidden])
Date: 2003-08-19 08:49:31

On Tue, 19 Aug 2003 13:25:37 +1000, Chris Trengove wrote
> I have some concerns about the implementation of the "period"
> concept, as given in period.hpp. First of all, the documentation
> (for, say, date_period) talks of the constructor
> date_period(date begin,date last)
> as creating a period as [begin,last). But really what is meant here
> is that the "last" parameter is actually going to become the "end"
> of the period. This is clear from the implementation in period.hpp,
> which is
> template<class point_rep, class duration_rep>
> inline
> period<point_rep,duration_rep>::period(point_rep begin, point_rep
> end)

Yes, the function defintion is misleading. In the function implementation
(shown above) it is clear that this is the end.

> I think there are two errors in the implementation of the period
> class, perhaps caused by this confusion between "last" and "end".
> 1) is_null() is implemented as
> return last_ <= begin;
> which means that a period of length 1 is judged as being "null". The
> correct implementation should be
> return end() <= begin;
> or
> return last < begin;

Yep. Fixed in CVS.
> 2) operator<() is implemented as
> return (last_ <= rhs.begin_);
> and this should be
> return (end() <= rhs.begin_);
> or
> return (last_ < rhs.begin_);

Yep. Fixed in CVS.

> Also, I think that the implementation would be simpler and more
> efficient if _end was chosen as the data member, rather than _last.
> ... detail omitted...

Probably true, I'll put this on the todo list to look at.

Thanks for the detailed comments.


Boost list run by bdawes at, gregod at, cpdaniel at, john at