Combining infinite ranges

[bearophile]

Andrei Alexandrescu:

> My point was that there's no need to sit down and implement 
> functionality. Just write
> 
> auto enumerate(R)(R r) if (isInputRange!R)
> {
>      return zip(iota(0, size_t.max), r);
> }

Right, thank you. A std lib can contain even small functions/HOFs (that are the result of combination of few other things), if they are very commonly useful.

Bye,
bearophile