Signature:

      SUBROUTINE h5pget_virtual_srcspace_f(dcpl_id, index, ds_id, hdferr)
        INTEGER(HID_T) , INTENT(IN)  :: dcpl_id
        INTEGER(SIZE_T), INTENT(IN)  :: index
        INTEGER(HID_T) , INTENT(OUT) :: ds_id
        INTEGER, INTENT(OUT)         :: hdferr

Inputs:

      dcpl_id - The identifier of the virtual dataset creation property list.
      index   - Mapping index.
                The value of index is 0 (zero) or greater and less than count
                (0 ≤ index < count), where count is the number of mappings
                returned by h5pget_virtual_count.

Outputs:

      ds_id  - dataspace identifier
      hdferr - Returns 0 if successful and -1 if fails.