Static memfun through null ptr

[Oliver Anhuth]

Hello all,

is it legal to call a static member function with a null pointer?

Is this correct C++?

class X {
public:
static void f() {}
};

int main() {
X* pX = 0;
pX->f();
}

Thanks Oliver

[Gianni Mariani]

Re: Static memfun through null ptr

Oliver Anhuth wrote:[color=blue]
> Hello all,
>
> is it legal to call a static member function with a null pointer?
>
> Is this correct C++?
>
> class X {
> public:
> static void f() {}
> };
>
> int main() {
> X* pX = 0;
> pX->f();
> }
>
> Thanks Oliver[/color]

No, it is not legal.

The behaviour is undefined.

[Ron Natalie]

Re: Static memfun through null ptr


"Oliver Anhuth" <q4708253@bonsa i.fernuni-hagen.de> wrote in message news:bjmjpn$l6p $1@beech.fernun i-hagen.de...[color=blue]
> Hello all,
>
> is it legal to call a static member function with a null pointer?
>[/color]
No. It is illegal to dereference, that is apply * or -> to a null pointer
even if the result would appear not to care about the actual value of
the pointer.

[Howard]

Re: Static memfun through null ptr


"Oliver Anhuth" <q4708253@bonsa i.fernuni-hagen.de> wrote in message
news:bjmjpn$l6p $1@beech.fernun i-hagen.de...[color=blue]
> Hello all,
>
> is it legal to call a static member function with a null pointer?
>
> Is this correct C++?
>
> class X {
> public:
> static void f() {}
> };
>
> int main() {
> X* pX = 0;
> pX->f();
> }
>
> Thanks Oliver[/color]

No, it's not legal, but if it's static then you don't need an instance
variable at all. Just call it like this:

X::f();

-Howard