Unionize range types

[Jakob Ovrum via Digitalmars-d-learn]

On Tuesday, 3 November 2015 at 01:55:27 UTC, Freddy wrote:
> Is there any way I can Unionize range Types?
> ---
> auto primeFactors(T)(T t, T div = 2)
> {
>     if (t % div == 0)
>     {
>         return t.only.chain(primeFactors(t / div, div));
>     }
>     if (div > t)
>     {
>         return [];
>     }
>     else
>     {
>         return primeFactors(t, div + 1);
>     }
> }
>
> ---

http://dlang.org/phobos/std_range#choose