[ntuple] Allow users to specify a per-field read callback function

[jalopezg-git]

As per a conversation with @jblomer on 16/11/2022 (and probably also related to #11628 (comment)), it would be useful to provide a way for users to set a per-field callback function to be invoked after reading a value object.

As an alternative to the (yet to be supported) manual schema evolution rules, this can be used as a simple way to inspect/modify the value object after reading.

Describe the solution you'd like

Something similar to RFieldBase::SetReadCallback(void (*)(RFieldValue&)) might be part of the RFieldBase public interface in order to allow users to set such callback.

[jalopezg-git]

This feature is related to issue #10019.

[github-actions]

Hi @jalopezg-r00t,

It appears this issue is closed, but wasn't yet added to a project. Please add upcoming versions that will include the fix, or 'not applicable' otherwise.

Sincerely,
🤖