h5网站建设作用,微网站建设,红动中国免费素材网站,深圳在哪些网站找什么好处在下面的示例中#xff0c;我将演示如何创建一个工厂类#xff0c;该工厂类能够生成四个不同类型的单例对象#xff0c;每个单例对象都通过单独的工厂方法进行创建。
#include iostream
#include mutex// Singleton base class
class Singleton {
protecte…在下面的示例中我将演示如何创建一个工厂类该工厂类能够生成四个不同类型的单例对象每个单例对象都通过单独的工厂方法进行创建。
#include iostream
#include mutex// Singleton base class
class Singleton {
protected:Singleton() {}public:Singleton(const Singleton) delete;Singleton operator(const Singleton) delete;static Singleton getInstance() {static Singleton instance;return instance;}void doSomething() {std::cout Singleton is doing something. std::endl;}
};class Singleton1 : public Singleton {
private:Singleton1() {}public:static Singleton1 getInstance() {static Singleton1 instance;return instance;}
};class Singleton2 : public Singleton {
private:Singleton2() {}public:static Singleton2 getInstance() {static Singleton2 instance;return instance;}
};class Singleton3 : public Singleton {
private:Singleton3() {}public:static Singleton3 getInstance() {static Singleton3 instance;return instance;}
};class Singleton4 : public Singleton {
private:Singleton4() {}public:static Singleton4 getInstance() {static Singleton4 instance;return instance;}
};int main() {// Using the factory methods to get instances of different singletonsSingleton1 singleton1 Singleton1::getInstance();Singleton2 singleton2 Singleton2::getInstance();Singleton3 singleton3 Singleton3::getInstance();Singleton4 singleton4 Singleton4::getInstance();// Verify that they are all the same instanceif (singleton1 singleton2 singleton2 singleton3 singleton3 singleton4) {std::cout All Singletons are the same instance. std::endl;}singleton1.doSomething();singleton2.doSomething();singleton3.doSomething();singleton4.doSomething();return 0;
}在这个示例中我们创建了一个基类 Singleton它实现了单例模式的基本机制然后创建了四个派生类 Singleton1、Singleton2、Singleton3 和 Singleton4每个派生类都有自己的工厂方法 getInstance 来创建对应的单例对象。
通过这种方式每个派生类继承了单例的行为但每个单例对象都是独立的实例。当我们调用工厂方法来获取这些单例对象时它们确保只有一个实例存在而且每个工厂方法创建的实例是不同的即每个单例类都有自己的单例实例。
