模板实现一个任意类型创建

#include <iostream>
#include <memory>


#define REGISTER_MESSAGE_TYPE(data, type) \
    data = std::make_shared<type>(); \

template<typename T>
class test
{
private:
   std::shared_ptr<T> proto_;
public:
    test() :proto_ (nullptr){
        REGISTER_MESSAGE_TYPE(proto_,T);
    }
    void set(T v) {
        *proto_ = v;
    }
    void print() const {
        std::cout << *proto_<<std::endl;
    }
    ~test() = default;
};




int main(int argc, const char** argv) {

    test<int> t;
    t.set(1);
    t.print();

    test<std::string> t1;
    t1.set("aaaaa");
    t1.print();
    return 0;
}