C++虚函数和函数指针一起使用

C++虚函数和函数指针一起使用，写起来有点麻烦。

下面贴出一份示例代码，可作参考。(需要支持C++11编译)

#include <stdio.h>
#include <list>
using namespace std;

class VirtualWithCallBack {
public:
    using CallBack = void(VirtualWithCallBack::*)(int);

public:
    virtual void testCallBack(int arg) = 0;

    virtual CallBack getCallBack() const = 0;
};

class VirtualWithCallBackSample1 : public VirtualWithCallBack {
public:
    VirtualWithCallBackSample1() {
        callBack = &VirtualWithCallBack::testCallBack;
    }

public:
    void testCallBack(int arg) override {
        printf("This is virtual call 1 : arg = %d
", arg);
    }

    CallBack getCallBack() const override {
        return callBack;
    }

private:
    CallBack callBack = nullptr;
};

class VirtualWithCallBackSample2 : public VirtualWithCallBack {
public:
    VirtualWithCallBackSample2() {
        callBack = &VirtualWithCallBack::testCallBack;
    }

public:
    void testCallBack(int arg) override {
        printf("This is virtual call 2 : arg = %d
", arg);
    }

    CallBack getCallBack() const override {
        return callBack;
    }

private:
    CallBack callBack = nullptr;
};

class VirtualCaller {
public:
    void push(VirtualWithCallBack* callBack) {
        callBackList.push_back(callBack);
    }

    void run() {
        for (auto r : callBackList) {
            (r->*(r->getCallBack()))(99);
        }
    }

private:
    list<VirtualWithCallBack*> callBackList;
};

int main() {
    VirtualCaller caller;
    caller.push(new VirtualWithCallBackSample1());
    caller.push(new VirtualWithCallBackSample2());
    caller.run();
    return 0;
}

运行结果

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