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From: gate02@wrandyke.demon.co.uk (Michael Mounteney)
Newsgroups: comp.lang.ada
Subject: Efficiently setting up large quantities of constant data
Date: 13 Dec 2004 13:48:49 -0800
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Date: 2004-12-13T13:48:49-08:00
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I want to set up about 100 variables which somehow reference
variable-length arrays of other things.  The other things, for a given
variable, are fixed.  Simplifying:

     type component is
          record
               X : character;
          end record;

     type component_list is array (positive range <>) of component;

     type component_ref is access all component_list;

     type structure is
          record
               part : component_ref;
          end record;

So I will have lots of structures scattered about, which will be
completely constant.  I would like to enforce this constancy, but Ada
(as far as I know) does not (unlike C++;  that should get some hackles
rising) allow `constant' to be splashed about in type definitions. 
This is on GNAT, which does not support pragma read_only.

Is there any way to ensure that these data are not modified, other
than by forbidding direct access to structure.part etc?