Re: What's the purpose of these parentheses in the #define's?

[Philippe Lhoste <PhiLho@...>]

On 26/01/2015 10:00, Philipp Janda wrote:
> Am 26.01.2015 um 08:51 schröbte William Ahern:
> > The macro arguments might themselves be comma expressions. So the
> > parentheses aren't useless.
>
> You can't have comma expressions without parentheses in argument lists.
>
>      #define X(a, b) ...
>
>      X(1, 2); /* ok */
>      X(1, 2, 3); /* constraint violation: wrong number of arguments */
>      X((1, 2), 3); /* ok, using comma expression as first argument */

What about vararg functions? (My C is rusty, so it can be an invalid remark!)

Of course, this discussion is mostly theoretical, I would say as above the parentheses are 
here mostly for consistency (with other macros) and common practice.

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Philippe Lhoste
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