C++学习笔记之类成员指针

struct point1{
	int x, y, z;
};

struct point2{
	int c[3];
};

int A:: *member = &A::x;

point1 tmp{4, 5, 6};
cout << tmp.(*member); //把member解引用，得到tmp::x，表示要访问x

int A:: *member [] = {&A::x, &A::y, &A::z};
for (int i = 0; i < 3; ++i)
	cout << tmp.(*member[i]);

struct A{
	int a, b, c;
};

main() {
	printf("%d%d%d", &A::a, &A::b, &A::c); //! 输入为0, 4, 8
	//! 当然这玩意类型不是int，printf直接将他以int解析输出了，所以cout达不到效果
}

#include <iostream>
#include <functional>
using namespace std;
class Compute
{
public:
    Compute(int a, int b) :a(a), b(b)
    {
 
    }
    int add()
    {
        return a + b;
    }
    int sub() const
    {
        return a - b;
    }
private:
    int a;
    int b;
};
int main(void)
{
    Compute com(100, 10), *p = &com;
    auto fun1 = mem_fn(&Compute::add);
    cout << fun1(com) << endl;
    cout << fun1(p) << endl;
    auto fun2 = mem_fn(&Compute::sub);
    cout << fun2(com) << endl;
    cout << fun2(p) << endl;
    cin.get();
    return 0;
}