What is the 'Result' type even for?

[Ruby The Roobster]

On Friday, 20 January 2023 at 03:30:56 UTC, Steven Schveighoffer 
wrote:
> On 1/19/23 10:11 PM, Ruby The Roobster wrote:
> ...
>
> The point is to be a range over the original input, evaluated 
> lazily. Using this building block, you can create an array, or 
> use some other algorithm, or whatever you want. All without 
> allocating more space to hold an array.
>
> -Steve

I get the point that it is supposed to be lazy.  But why are 
these basic cases not implemented?  I shouldn't have to go write 
a wrapper for something as simple as casting this type to the 
original type.  This is one of the things that one expects the 
standard library to do for you.