iota result as member variable

[Edwin van Leeuwen via Digitalmars-d-learn]

On Thursday, 24 March 2016 at 06:54:25 UTC, Alex wrote:
> Hi everybody,
> doing some optimization on my code, I faced some strange 
> question:
> how to save a iota result in a class member?
>
> Say I have
> class A
> {
>     ??? member;
>
>     auto testIter4()
>     {
>         return iota(0,5);
>     }
> }
>
> void main()
> {
>     A a = new A();
>     a.member = testIter4();
> }
>
> how would I declare the member?
>

Yeah this is one of the downsides of voldermort types. In these 
cases typeof and ReturnType are your friend. It often takes me a 
couple of tries to get it right, but the following seems to work:

import std.traits : ReturnType;
import std.range : iota;
class A
{
     ReturnType!(A.testIter4) member;
     auto testIter4()
     {
         return iota(0,5);
     }
}

void main()
{

      A a = new A();
      a.member = a.testIter4();
	
}