Reason for 'static struct'

[Jon D via Digitalmars-d-learn]

On Wednesday, 9 December 2015 at 21:23:03 UTC, Daniel Kozák wrote:
> V Wed, 09 Dec 2015 21:10:43 +0000
> Jon D via Digitalmars-d-learn 
> <digitalmars-d-learn at puremagic.com>
> napsáno:
>
>> There is a fair bit of range related code in the standard 
>> library structured like:
>> 
>>      auto MyRange(Range)(Range r)
>>          if (isInputRange!Range)
>>       {
>>          static struct Result
>>          {
>>              private Range source;
>>              // define empty, front, popFront, etc
>>          }
>>          return Result(r);
>>      }
>> 
>> I'm curious about what declaring the Result struct as 'static' 
>> does, and if there are use cases where it be better to exclude 
>> the static qualifier.
>> 
>> --Jon
>
> It make it non-nested struct: 
> https://dlang.org/spec/struct.html#nested

Thanks. So, is in the example above, would the advantage be that 
'static' avoids saving the enclosing state, which is not needed?