编辑代码

#include <iostream>
using namespace std;

static bool default_func(int r) {
    return false;
}

typedef bool(*cal_func)(int);

class AAA {
    public:
        static cal_func user_func;

        static bool run_callback_func(int r) {
            cout << "run_callback_func\n" << endl;
            user_func(r);
        };
        
};

static bool my_user_func(int r) {
    cout << "my_user_func:" << endl;
    cout << r << endl;
    return true;
}
// 静态成员变量只能在全局范围内赋值
cal_func AAA::user_func = &default_func;

int main() {
	cout << "Hello world!    - cpp.jsrun.net." << endl;
    cout << AAA::run_callback_func << endl;
    AAA::user_func = &my_user_func;
    AAA::run_callback_func(666);
	return 0;
}