singletonpattern2.cpp

来自「很经典的书籍」· C++ 代码 · 共 27 行

//: C10:SingletonPattern2.cpp
// Meyers' Singleton
#include <iostream>
using namespace std;

class Singleton {
  int i;
  Singleton(int x) : i(x) { }
  void operator=(Singleton&);
  Singleton(const Singleton&);
public:
  static Singleton& instance() {
    static Singleton s(47);
    return s;
  }
  int getValue() { return i; }
  void setValue(int x) { i = x; }
};

int main() {
  Singleton& s = Singleton::instance();
  cout << s.getValue() << endl;
  Singleton& s2 = Singleton::instance();
  s2.setValue(9);
  cout << s.getValue() << endl;
} ///:~