- it is not directly possible to provide a variadic join(args...),
due to overload resolution ambiguities
- as a remedy, simplify the invocation of stringify() for the typical cases,
and provide some frequently used shortcuts
...for the operation on a PlantingHandle, which allows
to implant a sub type instance into the opaque buffer.
* "create" should be used for a constructor invocation
* "emplace" takes an existing object and move-constructs
