get_partial_reshape Function

  function get_partial_reshape(this, upstream_grad) result(output)
    implicit none
    class(array_type), intent(inout) :: this
    type(array_type), intent(in) :: upstream_grad
    type(array_type) :: output
    type(array_type), pointer :: ptr

    ptr => reshape( &
         upstream_grad, new_shape = this%indices &
    )
    call output%assign_and_deallocate_source(ptr)
  end function get_partial_reshape