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;

}