fold on empty range

[Rumbu]

On Wednesday, 17 February 2021 at 12:58:29 UTC, Mitacha wrote:
> On Wednesday, 17 February 2021 at 11:38:45 UTC, Rumbu wrote:
>> [...]
>
> If you replace `fold` and `splitter` with this, then it doesn't 
> allocate:
> ```
> auto fn() @nogc {
>     return only("k1,k2", "k3,k4")
>         .map!(x => x.splitter(","))
>         .joiner;
> }
>
> void main() {
>    auto range = fn();
>    range.writeln;
> }
> ```
Wow, thanks a lot.