如何解释 c++11 中的 static 代码

Question

I just found some source codes, written in C++11. The code is like this:

inline Class& function() {
    static Class x;
    return x;
}

and then for using this function I faced:

function().app();

Is this function() implements the Singleton Pattern? How it is working? It seems strange to me.

Answer 1

The subroutine-static means on the stack, and return & means return a pointer to that, all very singular but no guarantee there is no Class x elsewhere in the process. Wiki says you must hide the constructor, have a class method to return a reference to a class-static object: https://en.wikipedia.org/wiki/Singleton_pattern