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Subject: Re: Teaching new tricks to an old dog (C++ -->Ada)
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From: Pascal Obry <pascal@obry.org>
Date: 09 Mar 2005 09:52:13 +0100
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Date: 2005-03-09T09:52:15+01:00
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Ioannis Vranos <ivr@remove.this.grad.com> writes:

> Pascal, this looks like Pascal.

Agreed.

> The C++ equivalent:
> 
> 
> #include <vector>
> 
> // ...
> 
> 
> using namespace std;
> 
> vector<int> Data(10);
> 
> for(vector<int>::size_type i=0; i<Data.size(); ++i)
> {
>      if (Data[i]== 1)

And no C++ compiler will check that Data[i] is valid. That's the point. If you
add the check explicitly no C++ compiler will be able to remove it. In the Ada
case the compiler knows lot more about the program and can decide to remove
the check if it knows that the index will never be outside the object
range. This is always the case for:

   for K in Data'Range loop
      ... Data(k)...

Pascal.

-- 

--|------------------------------------------------------
--| Pascal Obry                           Team-Ada Member
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