[phobos] phobos commit, revision 1566

[Andrei Alexandrescu]

On 05/29/2010 02:51 PM, Philippe Sigaud wrote:
>   Steve:
>  > Arguably, Take should never support back and popBack.
>  > If you have a random access range, why wouldn't you just do r[0..3]?
>
> Because your range may not have opSlice defined. And is such a slice
> always lazy?

I think the correct answer is that with take(r, 5) you take maximum 5 
elements from any range (more general), whereas with r[0 .. 5] you take 
exactly 5 elements from a range defining opSlice (most often, random 
access) - which is a more specialized function.

There's a tacit rule that has r.opSlice(a, b) return the same type as r 
itself.

I'm not sure if take does that already, but it should simply morph into 
opSlice() if opSlice() is available. No need to use another layer when 
opSlice does what you need.


Andrei