C++ Singleton 实现

此方法为线程安全的

#include <iostream>



using namespace std;



class A

{

    public:

        static inline A& instance(void)

        {

            static A a;

            return a;

        }

        

        int b;

    private:

        A(void);

        ~A(void);

};



A::A()

{

    b = 4;

}



A::~A()

{



}



int main(int argc, char *argv[])

{

    cout << A::instance().b << endl;



    return 0;

}