为什么通过指针静态访问类数据成员返回1？

Given the following code:

给出以下代码:

#include <iostream>

using std::cout;

class A {
    public:
        virtual ~A() {}
        int x,y,z;
};

int main (void)
{
    std::cout<<&A::x;
    std::cout<<&A::y;
    std::cout<<&A::z;
}
#include