C++中如何实现函数指针回调 与lambda表达式结合的现代写法

typedef void (*CallbackFunc)(int);

void register_callback(CallbackFunc cb) {
    if (cb) {
        cb(42);  // 假设触发某个事件后调用回调
    }
}

void my_callback(int value) {
    std::cout << "Value: " << value << std::endl;
}

register_callback(my_callback);

#include <functional>

void register_callback(std::function<void(int)> callback) {
    if (callback) {
        callback(42);
    }
}

register_callback([](int value) {
    std::cout << "Lambda got: " << value << std::endl;
});

register_callback(my_callback);

class MyClass {
public:
    void start() {
        register_callback([this](int value) {
            handle_event(value);
        });
    }

private:
    void handle_event(int value) {
        std::cout << "Handling event with m_value = " << m_value << ", value = " << value << std::endl;
    }

    int m_value = 10;
};

class MyService {
public:
    void register_me() {
        auto self = shared_from_this();
        register_callback([self](int) {
            self->do_something();
        });
    }

private:
    void do_something() { /* ... */ }
};

register_callback([weakSelf = weak_from_this()](int) {
    if (auto self = weakSelf.lock()) {
        self->do_something();
    }
});