[fpc-devel] bug: Inc(v,i)/Dec(v,i)

C Western mftq75 at dsl.pipex.com
Wed Jul 6 22:25:33 CEST 2005

Marco van de Voort wrote:
>>>>  v : cardinal;
>>>>  v:=100;
>>>>  inc(v,-1);
>>>>The reason is that -1 is in fact an addition of $ffffffff resulting in the
>>>>carry flag being set and therefor an overflow.
>>>For cardinal IMHO not-a-bug?
>>I think it's a bug for cardinals and other unsigned ints also (as long as the
>>result is in the range of the result variable)
> -1 is not a valid cardinal -> out of range -> rangecheck error.
But on the other hand Dec(v,1) is fine, so Inc(v,-1) should also work.

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