Re: [BLACKBOX] Overflow checking (was: Type transfer)

From: [at]} <Bernhard>
Date: Tue, 18 Oct 2011 10:48:00 +0200

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> Critical checks are absolutely necessary; indiscriminate overflow-checking
> is not necessarily a good thing. There are some occasions when overflow
> trapping might be useful and others where it should not be done. Some good
> examples are here:
>
> http://www.codeproject.com/KB/cs/overflow_checking.aspx
>

good point.

Let me put it this way:

I personally would prefer having them enabled by default.
It would also avoid the endless loop created by:

   VAR
       i : BYTE;

[...]

  FOR i := MIN(BYTE) TO MAX(BYTE) DO
      Something(i)
  END

This loop runs correctly when i is SHORTINT, INTEGER or LONGINT, but loops forever by silently overflowing from MAX(BYTE) to MIN(BYTE) when i is BYTE.

But it is correct that it is difficult to implement special algorithms, which depend on silent overflow, if you cannot control it.

regards
    Bernhard

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Received on Tue Oct 18 2011 - 10:48:00 UTC