[C++] DictionaryBuilder should use signed integers for indices #16957
Description
Unsigned integers are out of spec at the moment. I ran into this in ARROW-1199 so please check with me before starting a patch for this =)
Reporter: Wes McKinney / @wesm
Assignee: Uwe Korn / @xhochy
Related issues:
- Arrow 0.5.0 release (blocks)
Note: This issue was originally created as ARROW-1200. Please see the migration documentation for further details.