Re: [HACKERS] NAN code

>
> I have changed the NAN code, so if NAN is not defined, we just use 'num'
> as NAN, since we only get here if num is NAN. Seems like a good fix for
> platforms that can't assign a NAN to a variable.
>
> ---------------------------------------------------------------------------
>
> if (NUMERIC_IS_NAN(num))
> {
> result = (float32)palloc(sizeof(float32data));
> #ifdef NAN
> *result = NAN;
> #else
> *result = num;
> #endif
> return result;
> }

And I where so happy to have finally found that damned NAN
define :-}

Anyway - that above is absolutely wrong.

num is of type Numeric, which is a pointer to struct
NumericData! So the above should result in some compiler
warning (in fact it type casts a pointer into a double value
- and that will give unpredictable results).

Seems that only isnan() is defined as part of Posix. But not
a definition that can force a NAN. So we have to find a
portable way to define the value NaN for double and float.
Does anybody know of such a way?

Jan

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