メタデータ管理と動的プロパティ アクセスにおける C++ メタプログラミングの役割は何ですか?

template<typename T>
struct AttributeMetadata {
    std::string name;
    std::string type;
    bool is_required;
};

class MyClass {
    std::string name;
    int age;
    bool is_active;
};

static const AttributeMetadata<MyClass> attributeMetadata[] = {
    {"name", "std::string", false},
    {"age", "int", false},
    {"is_active", "bool", false}
};

for (const auto& attribute : attributeMetadata) {
    std::cout << "Name: " << attribute.name << std::endl;
    std::cout << "Type: " << attribute.type << std::endl;
    std::cout << "Required: " << (attribute.is_required ? "Yes" : "No") << std::endl;
}

class MyDynamicObject {
public:
    template<typename T>
    T getAttribute(const std::string& name) {
        return decltype(this->*name)();
    }

    template<typename T>
    void setAttribute(const std::string& name, const T& value) {
        (this->*name) = value;
    }
};

MyDynamicObject obj;
std::string name = obj.getAttribute<std::string>("name");
obj.setAttribute("age", 25);

template<typename T>
struct LogLevel {
    static const char* value;
};

struct Debug : LogLevel<Debug> { static const char* value = "DEBUG"; };
struct Info : LogLevel<Info> { static const char* value = "INFO"; };
struct Warning : LogLevel<Warning> { static const char* value = "WARNING"; };
struct Error : LogLevel<Error> { static const char* value = "ERROR"; };

class Logger {
public:
    template<typename L>
    void log(const char* message) {
        std::cout << "[" << LogLevel<L>::value << "] " << message << std::endl;
    }
};

int main() {
    Logger logger;
    logger.log<Debug>("This is a debug message");
    logger.log<Info>("This is an info message");
    logger.log<Warning>("This is a warning message");
    logger.log<Error>("This is an error message");
    return 0;
}

[DEBUG] This is a debug message
[INFO] This is an info message
[WARNING] This is a warning message
[ERROR] This is an error message