Class Adapter 範例 PlugAdapter 插頭轉接

上篇做了object adapter 範例，這篇輪到class Adapter，其實我上網爬了一陣子文，發現大家基本上都只寫object adapter範例（？）。 class Adapter通常利用多重繼承，讓一個類別繼承多個類別，獲得多個類別的屬性，就可以被當成其他類別使用。因為Java沒辦法用多重繼承，所以今天用C++來寫～

假設我們是歐洲人到美國旅遊，那就會需要歐規轉美規的轉接頭，這邊就簡單實作一下：

#include <iostream>
using namespace std;

// European plug interface
class EuropeanPlug {
    public:
        virtual void plugInEuropeanSocket() = 0;
};

// European charger for your smartphone
class EuropeanCharger : public EuropeanPlug {
    public:
        void plugInEuropeanSocket() override {
            cout << "Charging your smartphone with a European plug." << endl;
        }
};

// US socket interface
class USSocket {
    public:
        virtual void plugInUSSocket() = 0;
};

// Adapter to make European plug work with US socket
class PlugAdapter : public USSocket {
    private:
        EuropeanPlug* europeanPlug;

    public:
        PlugAdapter(EuropeanPlug* plug) : europeanPlug(plug) {}

        void plugInUSSocket() override {
            cout << "Using an adapter to plug your European charger into a US socket." << endl;
            europeanPlug -> plugInEuropeanSocket(); // Delegate to the European charger
        }
};

int main() {
    EuropeanPlug* europeanCharger = new EuropeanCharger();
    USSocket* adapter = new PlugAdapter(europeanCharger);

    // Now, you can plug your European charger into a US socket using the adapter.
    adapter -> plugInUSSocket();
}

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