ResPart_set_StoreOld Subroutine

    pure subroutine ResPart_set_StoreOld(this)
      !> Stores values from previous timestep
      implicit none
      class(ResPart_set), intent(inout) :: this                                !! Collection of Resolved Particles
      ! Work variables
      integer :: n,m

       select type (particle =>this%p)
       type is (ResPart_obj)
         do n=1,this%count_
           ! Position, linear, and angular velocities
           particle(n)%pold  = particle(n)%p
           particle(n)%vold  = particle(n)%v
           particle(n)%wold  = particle(n)%w

           ! Hydrodynamic and collisional forces
           particle(n)%Fhold = particle(n)%Fh
           particle(n)%Thold = particle(n)%Th
           particle(n)%Fcold = particle(n)%Fc
           particle(n)%Tcold = particle(n)%Tc
         end do
       end select

       select type (markers=>this%ib%p)
       type is (marker_obj)
         do m=1,this%ib%count_
           markers(m)%pold = markers(m)%p
           markers(m)%vold = markers(m)%v
         end do
       end select

       return
    end subroutine ResPart_set_StoreOld