"Design mode" singleton mode

1. Meyers Singleton

　　

1ClassSingleton {2Public:3Static singleton&GetInstance () {4StaticSingleton instance;5ReturnInstance6}78Private:9Singleton () {}Ten Singleton (const singleton&); 11 singleton& operator= ( const singleton&); 12 }; 13 14 int main () 15 {16 Singleton &s = Singleton::getinstance (); 18 return 0; 19}             

This is the way Scott Meyers Singleton in "effective C + +". It is a lazy pattern, that is, when the class instance is first invoked, a new instance of that class is generated, and only this instance is returned at a later time.

The disadvantage of Meyers Singleton is the problem of thread safety. It is thread-safe after c++11. However, the standard before c++11 does not have thread safety.

　　

"Design mode" singleton mode