[ARROW-7086] [C++] Provide a wrapper for invoking factories to produce a Result

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Won't Fix
• Affects Version/s: 0.15.1
• Fix Version/s: 0.16.0
• Component/s: C++
• External issue URL: https://github.com/apache/arrow/issues/23393
• Assignee: Ben Kietzman
• Reporter: Ben Kietzman
• Created: 07/Nov/19 14:16
• Updated: 11/Jan/23 07:51
• Resolved: 09/Dec/19 15:39

Description

There is a proliferation of code like:

Result<int> SafeAdd(int a, int b) {
  int out;
  RETURN_NOT_OK(SafeAdd(a, b, &out));
  return out;
}

Ideally, this should be resolved by moving the implementation of SafeAdd into the Result returning overload then using Result::Value in the Status returning function. In cases where this is inconvenient, it'd be helpful to have an adapter for doing this more efficiently:

Result<int> SafeAdd(int a, int b) {
  return RESULT_INVOKE(SafeAdd, a, b);
}

This will probably have to be a macro; otherwise the return type can be inferred but only when the function is not overloaded