module Subset

  procedure(SubRotInt0),pointer::subrot1a
  procedure(SubRotInt0),pointer::subrot1b
  procedure(SubRotInt1),pointer::subrot2a
  procedure(SubRotInt1),pointer::subrot2b

abstract interface
  subroutine SubRotInt0
  end subroutine SubRotInt0

  subroutine SubRotInt1(iovar)
    double precision,intent(in)::iovar
  end subroutine SubRotInt1
end interface

contains

subroutine SetSubset
  subrot1a => mysub1a
  subrot1b => mysub1b
  subrot2a => mysub2a
  subrot2b => mysub2b
end subroutine SetSubset

subroutine SetSubsetNull
  subrot1a => Dummy1
  subrot1b => Dummy1
  subrot2a => Dummy2
  subrot2b => Dummy2
end subroutine SetSubsetNull

subroutine SwapSubset
  procedure(SubRotInt0),pointer::tmpptr1 => NULL()
  procedure(SubRotInt1),pointer::tmpptr2 => NULL()
  tmpptr1 => subrot1a
  subrot1a => subrot1b
  subrot1b => tmpptr1
  tmpptr2 => subrot2a
  subrot2a => subrot2b
  subrot2b => tmpptr2
end subroutine SwapSubset

subroutine mysub1a
  write (*,*) "Calling mysub1a"
end subroutine mysub1a

subroutine mysub1b
  write (*,*) "Calling mysub1b"
end subroutine mysub1b

subroutine mysub2a(iovar)
  double precision,intent(in)::iovar
  write (*,*) "Calling mysub2a with ", iovar
end subroutine mysub2a

subroutine mysub2b(iovar)
  double precision,intent(in)::iovar
  write (*,*) "Calling mysub2b with ", iovar
end subroutine mysub2b

subroutine Dummy1
end subroutine

subroutine Dummy2(iovar)
  double precision, intent(in)::iovar
end subroutine

end module SubSet