anchor.diff:  !*****************************************************************************************
   
   !*****************************************************************************************
  -    function keys_equal(me,k1,k2)
  +    pure function keys_equal(me,k1,k2)
   
       !! Returns true if the two keys are equal.
       !!
  
positive.code:         procedure :: remove_by_pointer !! remove node given pointer
          procedure :: get_node          !! get a pointer to a node in the list
          procedure :: keys_equal        !! for testing key string equality
  
      end type list
  
  
negative.code:     nullify(me%value)
  
      end subroutine destroy_node_data
  !*****************************************************************************************
  
  !*****************************************************************************************
      subroutine list_finalizer(me)
  
      !! just a wrapper for [[destroy_list]].
  
      implicit none
  
      type(list),intent(inout) :: me
  
      call me%destroy()
  
      end subroutine list_finalizer
  !*****************************************************************************************
  
  !*****************************************************************************************
  