怎样实现C++中的命令模式？

#include <iostream>
#include <memory>

// 抽象命令类
class Command {
public:
    virtual ~Command() = default;
    virtual void execute() = 0;
};

// 具体命令类 - 打开灯
class LightOnCommand : public Command {
public:
    void execute() override {
        std::cout << "Turning on the light." << std::endl;
    }
};

// 具体命令类 - 关闭灯
class LightOffCommand : public Command {
public:
    void execute() override {
        std::cout << "Turning off the light." << std::endl;
    }
};

// 具体命令类 - 打开风扇
class FanOnCommand : public Command {
public:
    void execute() override {
        std::cout << "Turning on the fan." << std::endl;
    }
};

// 具体命令类 - 关闭风扇
class FanOffCommand : public Command {
public:
    void execute() override {
        std::cout << "Turning off the fan." << std::endl;
    }
};

// 遥控器类
class RemoteControl {
private:
    std::unique_ptr<Command> onCommand;
    std::unique_ptr<Command> offCommand;

public:
    void setCommands(std::unique_ptr<Command> on, std::unique_ptr<Command> off) {
        onCommand = std::move(on);
        offCommand = std::move(off);
    }

    void pressOnButton() {
        if (onCommand) {
            onCommand->execute();
        }
    }

    void pressOffButton() {
        if (offCommand) {
            offCommand->execute();
        }
    }
};

int main() {
    RemoteControl remote;

    remote.setCommands(std::make_unique<LightOnCommand>(), std::make_unique<LightOffCommand>());
    remote.pressOnButton();  // 输出: Turning on the light.
    remote.pressOffButton(); // 输出: Turning off the light.

    remote.setCommands(std::make_unique<FanOnCommand>(), std::make_unique<FanOffCommand>());
    remote.pressOnButton();  // 输出: Turning on the fan.
    remote.pressOffButton(); // 输出: Turning off the fan.

    return 0;
}