particle_obj_assign Subroutine

    pure subroutine particle_obj_assign(this,val)
      !> Assignment
      implicit none
      class(particle_obj), intent(inout) :: this                               !! An particle_obj object
      class(lagrangian_obj),  intent(in) :: val                                !! An particle_obj object
      select type (val)
      type is (particle_obj)
        this%id    = val%id
        this%p     = val%p
        this%c     = val%c
        this%s     = val%s
        this%d     = val%d
        this%rho   = val%rho
        this%v     = val%v
        this%w     = val%w
        this%Fh    = val%Fh
        this%Th    = val%Th
        this%Fc    = val%Fc
        this%Tc    = val%Tc
        this%pold  = val%pold
        this%vold  = val%vold
        this%wold  = val%wold
        this%Fhold = val%Fhold
        this%Thold = val%Thold
        this%Fcold = val%Fcold
        this%Tcold = val%Tcold
      end select

      return
    end subroutine particle_obj_assign