C++ Programming - Is static the problem?


#include < iostream >

using namespace std;

static int i;
class x {
 int i;
 public:
  x() { cout << "In HERE" << endl; }
  int geti() { return i; }
};


int main()
{
 cout << "Inside main() = " << ((x *)(&i+1))->geti() << endl;
 *(&i+1) = 17;
 cout << "Inside main() = " << ((x *)(&i+1))->geti() << endl;
 static x aa;
 cout << "Inside f() : " << aa.geti() << endl;
 x bb;
}

When we ran this on Intel Platform Linux (gcc 3.4.3 20041212, Red Hat 3.4.3-9.EL4) & Windows (.NET 2003) the results were very surprising (fcoz will be ;) but on Solaris it worked fine.

Could you guess what was the output on Intel Linux and Windows?

Labels: C++

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Published:: 9:05 am; by -

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samm 7:37 am

I see a couple of problems with the code:

1. casting from an int* to an x* is undefined, I belive the standard only supports casting to POD objects in cases like this. The class x is not a POD object since it has a private member variable.

2. I would prefer to use reinterpret_cast than to use the old c-style cast since it makes your intent much clearer. Though, the use of this cast would raise a flag to me since it often means non portable code.

3. The use of the static keyword to specify file local linkage is deprecated. You should use an anonymous namespace instead.

That said, I'm not surprised the results differ depending on your compiler and operating system.

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C++ Programming - Is static the problem?

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