C++中如何定义指向类成员的指针

class Test
{
public:
	Test(){ std::cout << "Test()" << std::endl; };
    void show() { std::cout << "show()" << std::endl; }
    static void fun(){ std::cout << "fun()" << std::endl; }

    int a;
    static int b;
};

int Test::b;

int main()
{
    //int * p  = &Test::a;
    //int Test::*p 转换为 int *
    Test t1;
    Test *t2 = new Test();

    int Test::* p = &Test::a;
    //依赖对象
    t1.*p = 200;
    std::cout << t1.*p << std::endl;
    //依赖对象
    t2->*p = 300;
    std::cout << t2->*p << std::endl;

    int * q = &Test::b;
    //不依赖对象
    *q = 400;
    std::cout << *q << std::endl;

    //pf指向的不是一般的全局方法，是属于Test类型下的成员方法
    //C风格定义函数指针，自然就不需要加类作用域了
    void (Test::*pf)() = &Test::show;
    (t1.*pf)();
    (t2->*pf)();

    //而静态方法调用是不需要依赖对象的
    void (*pfun)() = &Test::fun;
    pfun();
    return 0;
}