c++单例类

//singleton.h

#pragma once

template <typename T>

class Singleton

{

public:

template<typename... Args>

static T* Instance(Args&&... args)

{

if (m_pInstance == nullptr)

{

m_pInstance = new T(std::forward<Args>(args)...);

}

return m_pInstance;

}

static T* GetInstance()

{

if (m_pInstance == nullptr)

{

throw std::logic_error("Please initialize the instance first");

}

return m_pInstance;

}

static void DestroyInstance()

{

delete m_pInstance;

m_pInstance = nullptr;

}

private:

Singleton(void);

virtual ~Singleton(void);

//将拷贝构造函数和=操作符设置为私有的，禁止外在调用拷贝

Singleton(const Singleton&);

Singleton& operator = (const Singleton&);

private:

static T* m_pInstance;

};

template < class T> T* Singleton<T>::m_pInstance = nullptr;

////使用方式

//class A

//{

//public:

// void test(){};

//};

////使用方式

//Singleton<A>::Instance();

//Singleton<A>::GetInstance()->test();

//Singleton<A>::DestroyInstance();