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

[Satyam Sharma]

On 5/26/07, Al Viro <viro@xxxxxxxxxxxxxxxx> 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
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