指向成员函数的静态函数指针变量（hpho）

#include
using namespace std;

struct A {
    static void (A::*pfn)();
    void foo(){ cout << "a" << endl; }
};
void (A::*pfn)()=&A::foo;

int main() {
    pfn; // it's right, becasue pfn is a global variant
    A a;
    (a.*pfn)();
}

//////////////////////////////////////////////////////////////////////////////////

#include
using namespace std;

struct A {
    static void (A::*pfn)();
    void foo(){ cout << "a" << endl; }
};
void (A::*A::pfn)()=&A::foo;

int main() {
    // pfn; // it's wrong, becasue pfn is a member variant of A
    A a;
    (a.*A::pfn)();
}