编辑“︁C++ 适配器模式实现”︁（章节）

== 实际应用案例 ==  
'''场景'''：第三方支付接口与系统现有接口不兼容。  

<mermaid>  
classDiagram  
    class PaymentSystem {  
        <<interface>>  
        +processPayment()  
    }  
    class ThirdPartyPayment {  
        +makePayment()  
    }  
    class PaymentAdapter {  
        -ThirdPartyPayment* tpp  
        +processPayment()  
    }  
    PaymentSystem <|-- PaymentAdapter  
    PaymentAdapter o-- ThirdPartyPayment  
</mermaid>  

<syntaxhighlight lang="cpp">  
// 现有系统接口  
class PaymentSystem {  
public:  
    virtual void processPayment(float amount) = 0;  
};  

// 第三方支付类（不兼容接口）  
class ThirdPartyPayment {  
public:  
    void makePayment(float amount, const std::string& currency) {  
        std::cout << "Paid " << amount << " " << currency << " via ThirdParty\n";  
    }  
};  

// 适配器  
class PaymentAdapter : public PaymentSystem {  
private:  
    ThirdPartyPayment* tpp;  
public:  
    PaymentAdapter(ThirdPartyPayment* t) : tpp(t) {}  
    void processPayment(float amount) override {  
        tpp->makePayment(amount, "USD"); // 固定货币为USD  
    }  
};  

int main() {  
    ThirdPartyPayment* tpp = new ThirdPartyPayment();  
    PaymentSystem* ps = new PaymentAdapter(tpp);  
    ps->processPayment(100.0f); // 输出：Paid 100 USD via ThirdParty  
    delete ps;  
    delete tpp;  
    return 0;  
}  
</syntaxhighlight>