[PATCH v3 00/16] Introduce and use generic parity16/32/64 helper

Jiri Slaby jirislaby at kernel.org
Fri Mar 7 10:52:52 UTC 2025


On 07. 03. 25, 10:19, Kuan-Wei Chiu wrote:
> I used to believe that casting a boolean variable to int would always
> result in 0 or 1 until a few months ago when Waiman Long explicitly
> pointed out during a review that C does not guarantee this.
> 
> So I revisited the C11 standard, which states that casting to _Bool
> always results in 0 or 1 [1]. Another section specifies that bool,
> true, and false are macros defined in <stdbool.h>, with true expanding
> to 1 and false to 0. However, these macros can be #undef and redefined
> to other values [2].

Note that we do not have/use user's stdbool.h in kernel at all. Instead, 
in linux/stddef.h, we define:
enum {
         false   = 0,
         true    = 1
};

So all is blue.

thanks,
-- 
js
suse labs


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