singletonpattern.cpp

来自「C++编程思想第二版第一册答案」· C++ 代码 · 共 32 行

//: C25:SingletonPattern.cpp
// From Thinking in C++, 2nd Edition
// Available at http://www.BruceEckel.com
// (c) Bruce Eckel 1999
// Copyright notice in Copyright.txt
#include <iostream>
using namespace std;

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

Singleton Singleton::s(47);

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