条款14：在资源管理类中小心coping行为

class Mutex{};
void lock(Mutex* mutex) {}  //锁住资源
void unlock(Mutex* mutex) {} //释放资源

class MyLock
{
public:
	explicit MyLock(Mutex *mutex) :m_mutex(mutex)
	{
		lock(m_mutex);
	}

	~MyLock() {unlock(m_mutex);}
private:
	Mutex *m_mutex;
};

void process()
{
	Mutex mutex;
	MyLock mylock(&mutex);
	//process
} //离开作用域，mylock执行析构函数，释放mutex

void process()
{
	Mutex mutex;
	MyLock mylock(&mutex);
	MyLock mylock2(mylock);  //调用默认拷贝构造函数，指向同一个资源
	//process
} //离开作用域，mylock和mylock2执行析构函数，释放mutex两次

class MyLock : private Uncopyable {};

class Mutex{};
void lock(Mutex* mutex) {}  //锁住资源
void unlock(Mutex* mutex) {} //释放资源

class MyLock
{
public:
	explicit MyLock(Mutex *mutex) :m_mutexPtr(mutex, unlock)
	{
		lock(m_mutexPtr.get());
	}

	//~MyLock() {unlock(m_mutex);} //不用再定义析构函数，直接通过m_mutexPtr删除器释放资源
private:
	std::tr1::shared_ptr<Mutex> m_mutexPtr;

};

void process()
{
	Mutex mutex;
	MyLock mylock(&mutex);   //m_mutexPtr引用计数为2
	MyLock mylock2(mylock);  //调用默认拷贝构造函数，指向同一个资源,m_mutexPtr引用计数为2
	//process

} //离开作用域，成员对象mylock和mylock2的智能指针对象都执行析构函数且引用计数减为0，则调用删除器unlock()函数解除锁