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Date: Thu, 6 Feb 2014 08:13:28 -0800 (PST)
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Subject: Need help for constrained type
From: Gerd <GerdM.O@t-online.de>
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Date: 2014-02-06T08:13:28-08:00
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Hello,

can someone help me? 

This is my problem:

I have a record containing a constrainted array. I can write it like this:


  type Mem_Array is array (Natural range <>) of Short_Integer;

  type Memory_Block (len : Natural) is
    record
      Start_Address : Mem_Addr;
      Block_Size : Natural;
      Usage_Info : Mem_Array (1..len);
    end record;

  mem : Memory_Block (2**16);  --  for example


But i would like the indices of Usage_Info running from 0..len - 1 (C-style). But when I write

  type Memory_Block (len : Natural) is
    record
      Start_Address : Mem_Addr;
      Block_Size : Natural;
      Usage_Info : Mem_Array (0..len-1);
    end record;

the compiler tells me that this is not allowed.

Is it possible to allocate "len" units, but address them from 0 .. len - 1?

How can I do this?

Thanks.