[jira] [Created] (ARROW-15975) [C++] Document VisitArrayInline and type traits

["Will Jones (Jira)" <ji...@apache.org>]

Will Jones created ARROW-15975:
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             Summary: [C++] Document VisitArrayInline and type traits
                 Key: ARROW-15975
                 URL: https://issues.apache.org/jira/browse/ARROW-15975
             Project: Apache Arrow
          Issue Type: Improvement
          Components: C++
    Affects Versions: 7.0.0
            Reporter: Will Jones
            Assignee: Will Jones
             Fix For: 8.0.0


In ARROW-15952, we documented the {{ArrayVisitor}} and {{TypeVisitor}} classes. But as I discovered in [a cookbook PR|https://github.com/apache/arrow-cookbook/pull/166], you can't subclass these abstract visitors _and_ use type traits. Now I know why most visitor implementations within of Arrow don't subclasses these.

We should instead suggest users simply use the {{VisitArrayInline}} and {{VisitTypeInline}} with their visitors, and ignore the {{ArrayVisitor}} and {{TypeVisitor}} classes and associated {{Accept()}} methods. In fact, can we deprecate (or even remove) those? Do they add anything valuable?



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