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From: "Robert I. Eachus" <rieachus@attbi.com>
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Newsgroups: comp.lang.ada
Subject: Re: Elegant 'realloc'?
References: <slrnbihq0e.2j7.lutz@taranis.iks-jena.de>
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Date: 2003-08-01T00:01:54+00:00
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Lutz Donnerhacke wrote:
> When dealing with dynamically allocated variable length arrays, the
> allocated space might change. Is there a common idiom to simulate an
> 'realloc' (especially shrinking) other than, allocate, copy, free?
> 
>    declare
>       procedure Free is new Unchecked_Deallocation(T_Array, T_Array_Access);
>       oldp : constant T_Array_Access := current.field;
>    begin
>       current.field := new T_Array'(oldp(oldp'First .. current.last));
>       Free(oldp);
>    end;

I would just write:

   declare
     Current: T_Array(1..Whatever);
   begin
     -- process Current
   end;

The array Current gets put on the stack.  If you really need the array 
to be extensible, containing the old value, you can either use 
recursion, the heap, or Ada.Strings.Unbounded. ;-)

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