Re: lun - Lucky Number

Richard Heathfield in sci.crypt:

On 16/03/2025 14:57, Marcel Logen wrote:

Richard Heathfield in sci.crypt:

#define BIT_QRY(x,i) (((x)[(i)>>3] & (1<<((i)&7)))!=0)

>
This is actually another C question:
>
Why does it have to be "(x)" and "(i)" everywhere instead of
"x" and "i"? What kind of "protection" is meant here?

[...]

If in doubt, steer well clear of side effects in macros.

Ah, OK, all this refers to macros.

I had initially assumed that it was generally about paren-
theses around variable names.

Marcel