Messages in this thread | | | Date | Sat, 26 May 2007 03:07:15 +0530 | From | "Satyam Sharma" <> | Subject | Re: double exclamation (!!) suckage in the kernel |
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On 5/26/07, Al Viro <viro@ftp.linux.org.uk> 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.
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