[ARROW-17924] [Docs] Clarify immutability assumption in the C Data Interface documentation

• Type: Task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 10.0.0
• Component/s: Documentation, Format
• External issue URL: https://github.com/apache/arrow/issues/33133
• Assignee: Antoine Pitrou
• Reporter: Joris Van den Bossche
• Created: 04/Oct/22 08:57
• Updated: 11/Jan/23 11:57
• Resolved: 05/Oct/22 08:06

Description

The current documentation (https://arrow.apache.org/docs/dev/format/CDataInterface.html) is not explicit about whether there are any guarantees about (im)mutability.

My assumption is that the consumer of C Data Interface structs should assume the data to be immutable by default (unless they would know that the producer is fine with mutating the data). But it would be good to document this.

(as a reference, the DLPack Python docs mention this: https://dmlc.github.io/dlpack/latest/python_spec.html#semantics)