using std.algorithm to find intersection of DateTime[][] arg

[Laeeth Isharc via Digitalmars-d-learn]

On Thursday, 10 September 2015 at 11:58:10 UTC, deed wrote:
> On Wednesday, 9 September 2015 at 20:28:35 UTC, Laeeth Isharc 
> wrote:
>> I have a DateTime[][] arg ...
>> I would like to find the intersection of the dates.
>
> A suggestion:
>
> auto minLength      = arg.map!(a => a.length).reduce!min;
> auto minIdx         = arg.map!(a => 
> a.length).countUntil(minLength);
> auto intersection   = arg[minIdx].filter!(e => 
> chain(arg[0..minIdx], arg[minIdx..$]).all!(a => 
> a.assumeSorted.contains(e)));
>
> reduce with setIntersection seems the most straightforward, but 
> needs array AFAIK, i.e.:
>
> auto intersection =
> //reduce!((r, x) => setIntersection(r, x))(arg);      // 
> doesn't work
>   reduce!((r, x) => setIntersection(r, x).array)(arg);// does, 
> but with array

Thank you for this - exactly what I was looking for - and for the 
other answer.


Laeeth.