SQLite function to enable inserting single row from virtual table rarray / carray

I want to insert a single row from an rarray(?) (Rust equivalent of the carray extension, provided by rusqlite) which provides a single-column virtual table.

insert into mytable select somehow_transpose(*) from rarray(?)

How do I implement somehow_transpose?

Or somehow_load such that I could use:

insert into mytable values (somehow_load(rarray(?)))