functionstaticsingleton.cpp

来自「Think in C++ 2nd」· C++ 代码 · 共 30 行

//: C25:FunctionStaticSingleton.cpp
// From Thinking in C++, 2nd Edition
// Available at http://www.BruceEckel.com
// (c) Bruce Eckel 1999
// Copyright notice in Copyright.txt

class Singleton1 {
  Singleton1() {}
public:
  static Singleton1& ref() {
    static Singleton1 single;
    return single;
  }
};

class Singleton2 {
  Singleton1& s1;
  Singleton2(Singleton1& s) : s1(s) {}
public:
  static Singleton2& ref() {
    static Singleton2 single(Singleton1::ref());
    return single;
  }
  Singleton1& f() { return s1; }
};

int main() {
  Singleton1& s1 = Singleton2::ref().f();
} ///:~