Can't iterate over range

[Profile Anaysis via Digitalmars-d-learn]

On Saturday, 4 February 2017 at 14:35:37 UTC, ag0aep6g wrote:
> On 02/04/2017 12:31 PM, Profile Anaysis wrote:
>> I am trying to iterate over the combinations of a set using 
>> the code
>>
>> https://rosettacode.org/wiki/Power_set#D
>>
>> I have an array which I call powerSet on and I get a result of
>> MapResult. I have tried to foreach or front/popFront and even 
>> each() on
>> it but I can never get the result as the same array type that 
>> I started
>> with.
>
> To create an array from a range, you can use std.array.array:
>
> http://dlang.org/phobos/std_array.html#.array
>
>> What is MapResult(the algorithm that generates the result 
>> lazily?)
>
> Yes, it's a struct that gives you one element at a time, lazily 
> generated.
>
>> and
>> how do we easily iterate over the results like we would with 
>> an array?
>
> foreach and empty/front/popFront should both work. If you can't 
> get them to work, show what you tried.

well, I simply took the code from the page I linked and did a 
front() on the MapResult and it say the type was wrong. I thought 
it would give me the type I put in which was an array.

I guess maybe I needed to convert it to an array though... but I 
didn't try. I moved on it iterating over it manually.

someStruct[] X;
someStruct[] x = powerSet(X).popFront();

gave me an error. Was saying I was getting another MapResult, 
which I thought it shouldn't but maybe I just needed to convert 
it to an array.