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From: Andy Askey <ajaskey@mindspring.com>
Subject: Checking Access Parameters to Procedures
Date: 2000/03/06
Message-ID: <q6r8cscb2h8c9pmjhei7q1fk8hn6gimfpj@4ax.com>#1/1
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Organization: MindSpring Enterprises
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Newsgroups: comp.lang.ada
Date: 2000-03-07T02:50:45+00:00
List-Id: <comp.lang.ada>

Another, probably simple, question....

I want to check if a value passed into a procedure is NULL.  For
example:

package tst_pkg is
    type my_ttype is tagged private;
    procedure tst_proc(this : access my_ttype'class);
private
    type my_ttype is tagged
      record
         i : integer;
      end record;
end tst_pkg;

package body tst_pkg is

   procedure tst_proc(this : access my_ttype'class) is
   begin
      if (this = NULL) then
        ....
     end if;
   end tst_proc;
end tst_pkg;

This does not compile so I tried every combination I can think of and
nothing worked so far.  How can I test if "this" is a NULL pointer?

Thanx.

--
Andy Askey
ajaskey@mindspring.com