[ARROW-9434] [C++] Store type_code information in UnionScalar::value

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 6.0.0
• Component/s: C++
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/25508
• Assignee: Antoine Pitrou
• Reporter: Krisztian Szucs
• Created: 13/Jul/20 12:40
• Updated: 11/Jan/23 08:06
• Resolved: 02/Aug/21 15:34

Description

The format allows duplicated types in unions, so in order to properly construct an array from a unionscalar we need to know which type to use. Currently we only store the value as another scalar.

Issue Links

• links to: GitHub Pull Request #10817