Link QVariant to global variable

I have list of properties. Each property has a name and a QVariant value. I can access each property over the name(like QSettings).
I want to connect some property to a concrete global variable. If the value of property is changed the global variable should also be changed.
Here is some code to to show what i mean.

Code:

---

// global variable
double xy;  // could be any other type (e.g int,QPoint,QString etc.)
 
class Prop
{
private:
	QString mName;
	QVariant mValue;
	QVariant /*or void?? */ *mPointer; // should point to xy
 
public: 
	void SetPointer(/*Pointer to xy*/) 
	{ 
		mPointer = /*Pointer to xy*/;
	}
 
	void SetGlobalVariabel()
	{
                     // should set xy indirect with mPointer
	    */*Pointer to xy*/ = mValue.value();
	}
};

---

Is this possible? If yes, how can i do this.
There are other ways to change the global variable. But also this way should work.

If the global variable was also of type QVariant then this would be easy, but if you want to allow a generic type without QVariant, you have to provide some kind of "handlers" for different types and associate them with each global var. It'd be much easier if you used QVariant ;)

Now i have solved the problem with a handler:

Code:

---

// global variable
double xy;  // could be any other type (e.g int,QPoint,QString etc.) 
 
class Prop
{
private:    
   QString mName;    
   QVariant mValue;    
   void *mPointer; // should point to xy 
 
public:
   void SetPointer(void *pointer)     
   {         
      mPointer = pointer;    
   } 
 
   void SetGlobalVariabel() // should set xy indirect with mPointer   
   {                     
		  if (!mPointer) return;
 
	  	switch (mValue.type()) 
		  {
	  	case (QVariant::Double): {
			  *(static_cast<double*>(mPointer)) = mValue.value<double>();
			  break;
			  }
		  case (QVariant::Int): {
			  *(static_cast<int*>(mPointer)) = mValue.value<int>();
			  break;
			  }
		  default:
           ;
		  }
   }
};

---

SetPointer(&xy) links the QVariant variable to the global variable.
SetGlobalVariable() sets the global variable.

This is not exactly what i wanted but since i only need some types of QVariant it is the fastest way to solve the problem.

A more common solution should be possible if i would know the address(pointer) where QVariant stores the value of the variable.

But at the moment the problem is solved for me.

Thanks for the help.