std.v2020.algorithm etc[ WAS: Is run.d going to be expand for runtime and the phobos library?]

[Timon Gehr]

On 20.06.20 16:51, Andrei Alexandrescu wrote:
> 
> Input ranges should have only one API:
> 
> bool fetchNext(T& target);
> 
> Fill the user-provided target with the next element and return true. At 
> the end of the range, return false and leave the target alone.

What if the caller does not know how to construct a T?

Nullable!T fetchNext();

(I get that D's support for algebraic data types is subpar, but maybe 
that is something to look into.)