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Message-ID: <4pQF1fF90emTFwjr@ada-augusta.demon.co.uk>
From: Mike H <postmaster@ada-augusta.demon.co.uk>
Reply-To: Mike Hopkins <postmaster@ada-augusta.demon.co.uk>
Newsgroups: comp.lang.ada
Subject: Re: A question about private types
References: <$ql0lCCpEcmTFwCt@ada-augusta.demon.co.uk>
 <lncnhn$e4i$1@dont-email.me>
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In message <lncnhn$e4i$1@dont-email.me>, Jeffrey Carter 
<spam.jrcarter.not@spam.not.acm.org> writes
>A private type can't be used as an array index as you're doing here, 
>however. Perhaps that's really what you're complaining about.
>
>Even if Grid_Index_Type were private, Address could still be changed.
>
>Address would be harder to change if it were a discriminant:
>
>type Cell_Type (Address: Grid_Index_Type := Some_Initial_Value) is record
>    Data : Cell_Data;
>end record;
>
Thanks, perhaps I'll take a closer look at that. It may also solve a 
second niggling worry. If Grid_index_type is a subtype of some type that 
is range 0..81 then Some_initial_value = 0 could be used to flag an 
un-initialised grid.
-- 
Time flies like an arrow. Fruit flies like a banana.
Mike