C++类成员指针

类成员指针用法：

#include <iostream>
using namespace std;

class Test{
    public:
        static int x; //static member
        int y;
        int foo(int i){
            return i;
        }
        int Test::* get_y_ptr(){
            return &Test::y;
        }
};
int Test::x = 0;

int main(){
    cout<<hex<<&(Test::x)<<endl; //we can get address of static member directly
    Test t;
    Test * pt = &t;
    t.y = 0xdeadbeef;
    int Test::* p1 = &Test::y; //get member pointer of x
    cout<<hex<<t.*p1<<endl;
    cout<<hex<<pt->*p1<<endl;

    int Test::* p2 = t.get_y_ptr(); //get member pointer through function call
    cout<<hex<<t.*p2<<endl;
    cout<<hex<<pt->*p2<<endl;

    int (Test::*func)(int) = &Test::foo; //get member pointer of member function. pay attention to the position of '*'
    cout<<(t.*func)(0)<<endl;   // '()' around 't.*func' is essential
    cout<<(pt->*func)(0)<<endl;  // so is this case
    return 0;
}

估计成员指针中存放的是该成员在对象中的相对偏移。