Re: double exclamation (!!) suckage in the kernel

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 5/26/07, Al Viro <[email protected]> wrote:
On Sat, May 26, 2007 at 02:26:11AM +0530, Satyam Sharma wrote:
> also be brave enough to take a C quiz here :-)
>
> >        what type should x have for !!x to be a valid expression?
>
> Any integer type (includes pointers)

Er, no...  Pointers are not integer types *and* you can use ! on any
scalar type (including floating ones, even though it's not particulary
useful there).

Yeah, I noticed this (with a sample program) just after the quiz ...

> >        what will be the type of result?
>
> int (I guess boolean for C99?)

Actually, ! and comparisons still give int in C99 (and !x is defined as
(x == 0) in all situations).

Hmm, thanks for explaining this.

Satyam
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux