C++单例模式的自动生成资源管理器

    #include <iostream>
    using std::cout;
    using std::endl;
    
    class Singleton
    {
    public:
    	static Singleton * getInstance()
    	{
    		//使用懒汉模式时，在多线程环境下是非线程安全的
    		//可以通过加锁来实现线程安全
    		if(nullptr == _pInstance) {
    			_pInstance = new Singleton();
    		}
    		return _pInstance;
    	}
    
    private:
    	class AutoRelease
    	{
    	public:
    		AutoRelease() {	cout << "AutoRelease()" << endl;	}
    
    		~AutoRelease()
    		{
    			if(_pInstance) {
    				delete _pInstance;
    				cout << "~AutoRelease()" <