Re: Booch: missing r/w access through iterators

[mheaney@on2.com (Matthew Heaney)]

porton@ex-code.com (Victor Porton) wrote in message news:<3dc92622$0$308$bed64819@news.gradwell.net>...
> In Booch generic package BC.Containers there are
> function Current_Item which gives read-only access
> to the current item. Why a function giving direct
> read-write access to the current item (by returning
> access to it) is missing?!

The Charles library has such a function:

   generic
      type Element_Access is 
         access all Element_Type;
   function Generic_Element 
     (Iterator : Iterator_Type) return Element_Access;

This allows you to modify elements in place:

   type Element_Access is
     access all Element_Subtype;

   function To_Access is
     new Generic_Element (Element_Access);   

   declare
      E : Element_Type renames To_Access (Iterator).all;
   begin
      <now manipulate actual element object>
   end;

You can get the latest version of Charles at my home page:

http://home.earthlink.net/~matthewjheaney/charles/index.html