Eric Niebler wrote:
Jeff Garland wrote:
Jeff Garland wrote: Of
course, what I'm thinking is for the stock price rolling average example above you might want to use gregorian::date or posix_time::ptime to represent point of measurement of the stock price. I wasn't finding the requirements for the offset_type...which is what I think would need to be replaced. Right, I should document the requirements on the offset_type. The code has been tested with offset_types of int and double. I think the right concept for offset_type is LessThanComparible. Well, here's the thing. In date-time the 'duration_type' and the 'point_in_time_type' are different. For example, with dates you have 'date' as the 'point_in_time' which is conceptually dimensionless and the duration_type 'day'. If you subtract 2 points in time you get a duration. So it's possible there would need to be a different type in the mix to make
Eric Niebler wrote: things work. Anyway, this will be a good experiment at some point. I'd do it myself if I only had more time.... ;-)
Ah. So the type of (offset - offset) is not the same as the type of offset.
Well, depends on what we mean by an offset. From a concept perspective in date-time it goes something like this: TimePoint - Timepoint --> Duration TimePoint - Duration --> TimePoint Duration - Duration --> Duration concretely realized this means: date - date --> days date - days --> date days - days --> days Same for the time types only at a higher resolution.
That's not a problem in theory, but certainly the code doesn't handle that situation right now.
Yep, that's kinda what I was seeing. Jeff