I want to update an A cdt with another B cdt which is subset of A cdt. Is there

@sidhantb: Yes., its not OOTB but we are still using it in 16.1 without any issue. I did not understand the use case here completely so just thought of sharing an option to easily update CDTs. When we use updatecdt() we don't need to do any type casting and no need to mention all the fields as we do for updatearray() or normal variable to variable mapping.

It will be useful when we update very few fields among a large CDT.

And rule!returnModifiedChildValues here is just to do any data manipulation they want to do with the child cdt values. Like updating a lastModifiedDate field inside the child.

@sidhantb: Yes., its not OOTB but we are still using it in 16.1 without any issue. I did not understand the use case here completely so just thought of sharing an option to easily update CDTs. When we use updatecdt() we don't need to do any type casting and no need to mention all the fields as we do for updatearray() or normal variable to variable mapping.

It will be useful when we update very few fields among a large CDT.

And rule!returnModifiedChildValues here is just to do any data manipulation they want to do with the child cdt values. Like updating a lastModifiedDate field inside the child.