Is logical subsetting of an array possible ?

[Sahil via Digitalmars-d-learn]

On Thursday, 14 July 2016 at 11:01:20 UTC, Nicholas Wilson wrote:
> On Thursday, 14 July 2016 at 10:51:33 UTC, Nicholas Wilson 
> wrote:

> I should explain this a bit more if you are totally new to D.
>
> although filter looks like a method for an array type it is not 
> it is a function.
> in D function like f(a,b) can be rewritten as a.f(b);
>
> the '!' is the template instansiation operator (as filter is a 
> template function) and its template parameter is the predicate 
> to filter in this case ,(e => e>3).
>
> As with anyone totally new to D i cannot recommend more highly 
> Ali's book.

Yes, I have started with this book.
Thanks for the explanation!