eulerian_obj_SubEulerianRObj Function

    impure function eulerian_obj_SubEulerianRObj(this,in) result (res)
      !> Performs subtraction of real Eulerian objects.
      implicit none
      class(eulerian_obj_base), intent(in) :: this                             !! An Eulerian object
      type(eulerian_obj_r),     intent(in) :: in                               !! An Eulerian object
      type(eulerian_obj_r)                 :: res                              !! Result

      call res%Initialize(this%name,this%block,this%parallel,this%staggering)
      select type (this)
      type is (eulerian_obj_r)
          res%cell = this%cell-in%cell

      type is (eulerian_obj_i)
          res%cell = real(this%cell,wp)-in%cell

      class default
        call this%parallel%Stop("Error performing addition of Eulerian object")
      end select

      return
    end function eulerian_obj_SubEulerianRObj