Re: RFC: booleans and the kernel

Kai Henningsen (kaih@khms.westfalen.de)
25 Jan 2002 08:36:00 +0200


timothy.covell@ashavan.org (Timothy Covell) wrote on 25.01.02 in <200201242243.g0OMhAL06878@home.ashavan.org.>:

> On Thursday 24 January 2002 16:38, Robert Love wrote:
> > On Fri, 2002-01-25 at 17:30, Timothy Covell wrote:
> > > On Thursday 24 January 2002 16:19, Robert Love wrote:
> > > > how is "if (x)" any less legit if x is an integer ?
> > >
> > > What about
> > >
> > > {
> > > char x;
> > >
> > > if ( x )
> > > {
> > > printf ("\n We got here\n");
> > > }
> > > else
> > > {
> > > // We never get here
> > > printf ("\n We never got here\n");
> > > }
> > > }
> > >
> > >
> > > That's not what I want. It just seems too open to bugs
> > > and messy IHMO.
> >
> > When would you ever use the above code? Your reasoning is "you may
> > accidentally check a char for a boolean value." In other words, not
> > realize it was a char. What is to say its a boolean? Or not? This
> > isn't an argument. How does having a boolean type solve this? Just use
> > an int.
> >
> > Robert Love
>
> It would fix this because then the compiler would refuse to compile
> "if (x)" when x is not a bool. That's what I would call type safety.

But that's not what C actually does.

> But I guess that you all are arguing that C wasn't built that way and
> that you don't want it.

We're talking about a specific language feature, and that feature isn't
what you seem to be thinking it is. It does not change anything you can do
with ints.

MfG Kai
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