#include <iostream>
#include "boost/noncopyable.hpp"
template<class T>
class SingleInstance : public boost::noncopyable {
public:
    static inline T instance() {
        static T obj;
        return obj;
    }
};
class T {
public:
    void show() {
        std::cout << "show T...!" << std::endl;
    }
};
#define G_T SingleInstance<T>::instance()
int main() {
    G_T.show();

    return 0;
}