In working on ARROW-3762, I've found it's useful to be able to have functions return either Array or ChunkedArray. We might consider promoting the arrow::compute::Datum variant out of arrow/compute/kernel.h so it can be used in other places where it's helpful

Reporter: Wes McKinney / @wesm
Assignee: Wes McKinney / @wesm

Related issues:

• [C++] Improved declarative compute function / kernel development framework, normalize calling conventions (relates to)

_{Note: This issue was originally created as ARROW-4022. Please see the migration documentation for further details.}