#include <cstddef>
#include <iostream>
 
struct ICell
{
	virtual bool isEmtpy() = 0;
};
 
class MyCell : public ICell
{
	int value;
public:
	MyCell() :value(0)
	{
	}
 
	virtual bool isEmtpy()
	{
		return value == 0;
	}
};
 
void foo(ICell *cells, size_t sz)
{
    std::cout << "Base address " << &cells[1] << std::endl;
    std::cout << "Derived address " << &((MyCell*)cells)[1] << std::endl;
//	cells[1].isEmtpy(); //Access violation
    ((MyCell*)cells)[1].isEmtpy();
}
 
int main()
{
	MyCell *myCells = new MyCell[10];
	foo(myCells, 10);
	delete[] myCells;
 
	return 0;
}

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