如何在C++中检查对象是否为模板类的实例？

#include <iostream>

// 定义一个模板类
template <typename T>
class MyTemplateClass {
public:
    void print() {
        std::cout << "This is a template class." << std::endl;
    }
};

// 定义一个非模板类
class MyClass {
public:
    void print() {
        std::cout << "This is not a template class." << std::endl;
    }
};

// 定义一个模板元函数，用于检查对象是否为模板类的实例
template <typename T>
struct is_template_class {
    static constexpr bool value = false;
};

template <typename T>
struct is_template_class<MyTemplateClass<T>> {
    static constexpr bool value = true;
};

int main() {
    MyTemplateClass<int> obj1;
    MyClass obj2;

    if (is_template_class<decltype(obj1)>::value) {
        obj1.print();
    } else {
        std::cout << "obj1 is not a template class instance." << std::endl;
    }

    if (is_template_class<decltype(obj2)>::value) {
        obj2.print();
    } else {
        std::cout << "obj2 is not a template class instance." << std::endl;
    }

    return 0;
}