模板类创建对象的模板成员函数调用问题

#include <bits/stdc++.h>
// #include <boost/lexical_cast.hpp>

using namespace std;

class Caster1 {
public:
    template<typename R, typename T>
    R cast(const T& t) {
        stringstream ss;
        ss << t;
        R r;
        ss >> r;
        return r;
    }
};

// class Caster2 {
// public:
//     template<typename R, typename T>
//     R cast(const T& t) {
//         return boost::lexical_cast<R>(t);
//     }
// };

template<typename CAST_T>
class Test {
public:
    template<typename R, typename T>
    R cast(const T& t) {
        return CAST_T().cast<R>(t); // 此处会报错
    }
};


int main() {
    cout << Caster1().cast<double>("3.14") << endl;
    // cout << Caster2().cast<double>("3.14") << endl;

    Test<Caster1> test;
    cout << test.cast<double>("3.14") << endl;
   
    return 0;
}