[ARROW-7313] [C++] Add function for retrieving a scalar from an array slot

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.15.1
• Fix Version/s: 1.0.0
• Component/s: C++
• External issue URL: https://github.com/apache/arrow/issues/23598
• Assignee: Ben Kietzman
• Reporter: Ben Kietzman
• Created: 04/Dec/19 15:55
• Updated: 11/Jan/23 07:52
• Resolved: 06/Jun/20 22:03

Description

It'd be useful to construct scalar values given an array and an index.

/* static */ std::shared_ptr<Scalar> Scalar::FromArray(const Array&, int64_t);

Since this is much less efficient than unboxing the entire array and accessing its buffers directly, it should not be used in hot loops.

kszucs fsaintjacques