The documentation for mongoc_cursor_clone states that it returns a newly allocated struct that should be freed with a particular method (it links to mongoc_cursor_destroy. The docs for the session_opts and transaction_opts clone methods simply state that they create a copy of a struct in their "Synopsis" section. Those pages also don't have a "Returns" section as the cursor method does. I think they can be improved by 'd do well to link to the corresponding destroy method. Optionally, consider doing so in a "Returns" section for consistency.
Related pages: