On Thu, 17 Jan 2019 at 03:42, David Rowley <david.rowley@2ndquadrant.com> wrote:
> 35. The evaluation order of this macro is wrong.
>
> #define ITEM_SIZE(ndims) \
> (ndims * (sizeof(uint16) + sizeof(bool)) + 2 * sizeof(double))
>
> You'd probably want ITEM_SIZE(10) to return 170, but:
>
> select (10 * (2 + 1) + 2 * 8);
> ?column?
> ----------
> 46
>
> Unsure why this does not cause a crash.
>
No, the code is actually correct, as explained in the comment above
it. Each item contains (ndims) copies of the uint16 index and the
boolean, but it always contains exactly 2 doubles, independent of
ndims.
> ndims should also have parenthesis around it in case someone does
> ITEM_SIZE(x + y), likewise for the other ITEM_* macros.
>
+1 on that point.
Regards,
Dean
