C++怎么实现依赖注入(DI)_C++实现控制反转(IoC)以降低代码耦合度

class ILogger {
public:
    virtual ~ILogger() = default;
    virtual void log(const std::string& msg) = 0;
};

class FileLogger : public ILogger {
public:
    void log(const std::string& msg) override {
        // 写入文件
    }
};

class UserService {
    ILogger* logger;
public:
    // 构造函数注入
    explicit UserService(ILogger* logger) : logger(logger) {}

    void addUser(const std::string& name) {
        logger->log("Adding user: " + name);
        // 其他逻辑
    }
};

FileLogger fileLogger;
UserService userService(&fileLogger);
userService.addUser("Alice");

class ServiceContainer {
public:
    template<typename T>
    static std::shared_ptr<T> resolve() {
        if constexpr (std::is_same_v<T, ILogger>) {
            return std::make_shared<FileLogger>();
        }
        else if constexpr (std::is_same_v<T, UserService>) {
            auto logger = resolve<ILogger>();
            return std::make_shared<UserService>(logger.get());
        }
        return nullptr;
    }
};

auto userService = ServiceContainer::resolve<UserService>();
userService->addUser("Bob");

template<typename LoggerType>
class UserServiceT {
    LoggerType logger;
public:
    void addUser(const std::string& name) {
        logger.log("Adding user: " + name);
    }
};

UserServiceT<FileLogger> service1;
UserServiceT<ConsoleLogger> service2;

service1.addUser("Tom");