#include <stdio.h>
#include <iostream>

using namespace std;

template<typename T>
class A{
    private:
        A();

    public:
        A(const T &object);
        const T&fetch(const T&or_else = Default) const noexcept;

    public:
        static const T Default;

    private:
        T contents;
        bool has_something;
};

template<typename T>
const T A<T>::Default{"DEFAULT"};

template<typename T>
A<T>::A():contents{Default}, has_something{false}{}

template<typename T>
A<T>::A(const T &object):contents{object}, has_something{true}{}

template<typename T>
const T& A<T>::fetch(const T &or_else) const noexcept{
    if ( has_something )
        return contents;
    else
        return or_else;
}

int main()
{
    cout << "\nTest 1" << endl;
    A< string > hibox{ "Hello, world!" };
    cout << hibox.fetch() << endl;
    return 0;
}