[Patch] Fix undeleted "static QFont *_font" in kglobalsettings.cpp

Olivier Goffart ogoffart at kde.org
Sun Dec 14 17:03:17 GMT 2008

Le mardi 9 décembre 2008, Matthew Woehlke a écrit :
> Johannes Sixt wrote:
> > No, you are misunderstanding: It's not the integers that are stored in an
> > esoteric way, but the *null pointer*! There are architectures out there
> > where the null pointer does not have all bits set to zero. Nevertheless,
> > in the C++ program code you still write
> >
> >    Foo* x = 0;
> Eew, trying to think of what you'd have to do to the compiler to support
> this makes my head hurt ;-). Not to mention the gross violation of least
> surprise principle.

I can give you a very concrete example:

#include <iostream>
struct A {
	int a;
	int b;
int main() {
	int A::*m = 0;
	int A::*n = &A::a; 
	std::cout << " m = " << *(int*)(&m) << ", n = " << *(int*)(&n) << std::endl;

Compiles this program with gcc and the result is:
 m = -1, n = 0

Because the pointer is relative, the 0x000000 binary value points to the first 
member in the class.  So the sementic value 0 or NULL need to be something 
else (hence -1)

Some architecture may have also a relative addressing mechanism for normal 
pointer. (none that we support, ok)

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