On 10 October 2012 06:09, Anthony Toft <toftat@cowshed.us> wrote:

> But why? (the bane of my parent's existence)
>
> p++; only increments the value of the pointer on the stack, not the
> original pointer (&myInt or &anotherInt) nor the contents of the
> pointer.
>

Correct, it just tries to avoid situations where you may try to use the
pointer as an address of a buffer as opposed to a single element.

Tamas



>
> Here at work (I am 18 years into a software engineering career) I see
> examples of unnecessary const-ness all over the place, it causes any
> amount of trouble! The only time I have ever needed a <const_cast> is
> because of overzealous use of const parameters, the compiler will not
> remove const-ness without express permission, unlike adding it.
>
> Now, on the other hand, pointers to const objects or values ie "const
> int *p" I feel is an excellent idea, but once again, it's not the
> calling function saying "I won't allow him to change this" it's the
> called function saying "I promise I won't change it"
>
>
> On 2012-10-10 03:16, Tamas Rudnai wrote:
> > On 9 October 2012 18:22, Anthony Toft <toftat@cowshed.us> wrote:
> >
> >> Not sure that I've ever wanted a const pointer other than "int
> >> p[2];"
> >>
> >> What would you use it for?
> >>
> >
> > We can make sure a function never screws up a pointer causing hard to
> > debug
> > bugs... For example:
> >
> > void foo ( int * const p ) {
> >    *p =3D 1234; // works great
> >    p++; // hey, we do not want to do that! Error!
> > }
> >
> > main () {
> >   int myInt;
> >   int anotherInt;
> >
> >   foo ( &myInt );
> >   foo ( &anotherInt );
> > }
> >
> > $ gcc -o testConstPointer testConstPointer.c
> > testConstPointer.c: In function =91foo=92:
> > testConstPointer.c:5: error: increment of read-only location
> >
> >
> >
> >>
> >> -----Original Message-----
> >> From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On
> >> Behalf
> >> Of
> >> V G
> >> Sent: Tuesday, October 09, 2012 20:04
> >> To: Microcontroller discussion list - Public.
> >> Subject: Re: [OT] C/C++ pointer syntax
> >>
> >> Another case. What if you want to declare a const pointer like so:
> >> int *
> >> const p;?
> >>
> >> int *const p; looks weird, and it's illogical. How would you even go
> >> about
> >> trying to justify why the asterisk is touching the const keyword?
> >>
> >> int* const p; looks better.
> >>
> >> int * const p; looks the best
> >> --
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> >>
> >>
> >> --
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> >>
> >
> >
> >
> > --
> > int main() { char *a,*s,*q; printf(s=3D"int main() { char *a,*s,*q;
> > printf(s=3D%s%s%s, q=3D%s%s%s%s,s,q,q,a=3D%s%s%s%s,q,q,q,a,a,q); }",
> > q=3D"\"",s,q,q,a=3D"\\",q,q,q,a,a,q); }
>
> --
> http://www.piclist.com PIC/SX FAQ & list archive
> View/change your membership options at
> http://mailman.mit.edu/mailman/listinfo/piclist
>



--=20
int main() { char *a,*s,*q; printf(s=3D"int main() { char *a,*s,*q;
printf(s=3D%s%s%s, q=3D%s%s%s%s,s,q,q,a=3D%s%s%s%s,q,q,q,a,a,q); }",
q=3D"\"",s,q,q,a=3D"\\",q,q,q,a,a,q); }
--=20
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.