如何覆盖C++模板子类中的转换运算符？

#include <iostream>

template <typename T>
class Base {
public:
    operator T() const {
        return static_cast<T>(value_);
    }

protected:
    int value_ = 42;
};

class Derived : public Base<double> {
public:
    operator double() const {
        return value_ * 2.0;
    }
};

int main() {
    Derived d;
    double result = static_cast<double>(d);  // 调用子类的转换运算符
    std::cout << result << std::endl;  // 输出：84.0

    Base<int>& baseRef = d;
    int intValue = static_cast<int>(baseRef);  // 调用父类的转换运算符
    std::cout << intValue << std::endl;  // 输出：42

    return 0;
}