save() feature for iota

[Salih Dincer via Digitalmars-d-learn]

Hi All,

Isn't there a save feature for `iota()`?
```d
import std.stdio;
import std.range;

void main()
{
  foreach(num; iota!char('a', 'f').chunks(3)/*
              "onetwosixfour".chunks(3)//*/
  ) {
                //auto n = num.save();
                num.writeln(": ", num.walkLength);
  }
} /* Prints:
: 3
: 2
*/
```
So is there a way to find out the length of an `iota()` range 
without consuming it?

SDB@79