Signature:

      SUBROUTINE h5ovisit_f(object_id, index_type, order, op, op_data, &
                return_value, hdferr)
        INTEGER(HID_T), INTENT(IN) :: object_id
        INTEGER, INTENT(IN) :: index_type
        INTEGER, INTENT(IN) :: order

        TYPE(C_FUNPTR):: op
        TYPE(C_PTR)   :: op_data
        INTEGER, INTENT(OUT) :: return_value
        INTEGER, INTENT(OUT) :: hdferr

Inputs:

      object_id  - Identifier of the object at which the recursive iteration
                    begins.
      index_type - Type of index; valid values include:
                    H5_INDEX_NAME_F
                    H5_INDEX_CRT_ORDER_F
      order      - Order in which index is traversed; valid values include:
                    H5_ITER_DEC_F
                    H5_ITER_INC_F
                    H5_ITER_NATIVE_F
      op         - Callback function passing data regarding the group to the
                   calling application
      op_data    - User-defined pointer to data required by the application
                   for its processing of the group

Outputs:

      return_value - Returns the return value of the first operator that
                     returns a positive value, or zero if all members were
                     processed with no operator returning non-zero.
      hdferr       - Returns 0 if successful and -1 if fails.