request_get Function

   function request_get(this) result(mpi_request_out)
      class(request_t), intent(in) :: this
      integer :: mpi_request_out

      if (.not. this%is_valid) then
         error stop "Cannot get MPI_Request from null request"
      end if
      mpi_request_out = this%m_request
   end function request_get