Support for using current element index as source value when mapping collections

[crizzis]

Use case

It would be nice to be able to map the index of the current element in the source list to a property in the target collection. I imagine sth like @Mapping(source = "#currentIndex" target = "recordIndexField")

(bonus points, I suppose, for being able to reference it in other contexts as well, e.g. expression = "java(someCustomMethod(#currentIndex))")

Generated Code

No response

Possible workarounds

The only workaround I could think of was to iterate over the collection programmatically, which meant it was also clearer to use a per-element mapper, instead of a collection mapper

MapStruct Version

No response