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From: "David Botton" <David@Botton.com>
Subject: Re: Checking Access Parameters to Procedures
Date: 2000/03/06
Message-ID: <rh_w4.852$iJ2.121345@news4.usenetserver.com>#1/1
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Date: 2000-03-06T00:00:00+00:00
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"This" can not be NULL as it is passed in by "access". In the event that you
would like to pass in a NULL value, you would have to redefine your
procedure to have an in paramter of an access type.

For example:

package tst_pkg is
    type my_ttype is tagged private;
    type My_ttype_Access is access all My_ttype'Class;
    procedure tst_proc(this : My_Ttype_Access);

Andy Askey wrote in message ...
>I want to check if a value passed into a procedure is NULL.  For
>example:


>    procedure tst_proc(this : access my_ttype'class);