Re: CONSTRAINT_ERROR - why?

[Dennis Lee Bieber <wlfraed@ix.netcom.com>]

Alfred Hilscher fed this fish to the penguins on Sunday 15 December 
2002 05:45 am:

> 
> 
> Dennis Lee Bieber schrieb:
>> 
>> From the user guide:
>> 
>> -gnato
>>    Enables overflow checking for integer operations. This causes GNAT
>> to generate slower and larger executable programs by adding code to
>> check for overflow (resulting in raising Constraint_Error as required
>> by standard Ada semantics). These overflow checks correspond to
>> situations in which the true value of the result of an operation may
>> be
> 
> "... the result of an operation ..." The result of the operation "/"
> _does_ fit into a BYTE.
> 
>> outside the base range of the result type. The following example
>> shows the distinction:

        You stopped short of " *may* be outside"... I'll concede that I'd have 
thought the compiler could have made the determination -- given that 
the size of Fac_Conf_Struct is fixed at compile time. However, I expect 
the 'Size returns a value defined in some "type" (call it "size_type") 
which is probably 32-bit integer. So you have a 32-bit integer divided 
by an anoymous integer; the result of that division, based solely on 
the data types, /could/ exceed the result type BYTE.

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