[ARROW-328] [C++] Return shared_ptr by value instead of const-ref?

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.2.0
• Component/s: C++
• External issue URL: https://github.com/apache/arrow/issues/15326
• Assignee: Wes McKinney
• Reporter: Wes McKinney
• Created: 08/Oct/16 19:59
• Updated: 11/Jan/23 07:08
• Resolved: 10/Dec/16 08:06

Description

This is largely my fault but: many C++ programmers seem to feel that you should always return std::shared_ptr by value for a couple reasons:

• RVO in many cases prevents a double ref-count manipulation and,
• If you are planning to share ownership with the other class, you will need to copy the shared_ptr anyway

On some contemplation I'm +1 on changing all const std::shared_ptr<T>& to std::shared_ptr<T>, but let me know if there are other opinions.