智能指针 auto_ptr(C++ Primier-8)

//case 1)
auto_ptr<string> pstr1_auto(new string("auto ptr"));
auto_ptr<string> pstr2_auto(pstr1_auto);
cout<<*pstr2_auto<<endl;
//case 2)
auto_ptr<int> pi1_auto(new int(1024));
auto_ptr<int> pi2_auto(new int(2048));
pi1_auto = pi2_auto;
cout<<*pi1_auto<<endl; 
//case 3)
auto_ptr<int> p_auto_int;
if (p_auto_int.get() != 0 && *p_auto_int != 1024)
{cout<<"existing value"<<endl;*p_auto_int = 1024;
}
else
{p_auto_int.reset(new int(512));
}
cout<<*p_auto_int<<endl;
//set empty auto_ptr
p_auto_int.reset(0);
if (p_auto_int.get() == 0)
{cout<<"reset to 0"<<endl;
}

int* pInt = (int*)malloc(sizeof(int));
auto_ptr<int>pInt_auto(pInt); //not safe

auto_ptr<string>pstr_auto2(pstr_auto1.get()); //bad behavior;

#include <iostream>
#include <memory>
using namespace std;
class TC
{public:TC(){cout<<"TC()"<<endl;}~TC(){cout<<"~TC()"<<endl;}
};
void foo(bool isThrow)
{auto_ptr<TC> pTC(new TC);    // 方法2//TC *pTC = new TC;            // 方法1try{if(isThrow)throw "haha";}catch(const char* e){//delete pTC;           // 方法1throw;}//delete pTC;              // 方法1
}
int main()
{try{foo(true);}catch(...){cout<<"caught"<<endl;}system("pause");
}

template<class _Ty>  struct auto_ptr_ref  {   // proxy reference for auto_ptr copying  explicit auto_ptr_ref(_Ty *_Right)  : _Ref(_Right)  {   // construct from generic pointer to auto_ptr ptr  }  _Ty *_Ref;  // generic pointer to auto_ptr ptr  };  template<class _Ty>  class auto_ptr  {   // wrap an object pointer to ensure destruction  
public:  typedef auto_ptr<_Ty> _Myt;  typedef _Ty element_type;  explicit auto_ptr(_Ty *_Ptr = 0) _THROW0()  : _Myptr(_Ptr)  {   // construct from object pointer  }  auto_ptr(_Myt& _Right) _THROW0()  : _Myptr(_Right.release())  {   // construct by assuming pointer from _Right auto_ptr  }  auto_ptr(auto_ptr_ref<_Ty> _Right) _THROW0()  {   // construct by assuming pointer from _Right auto_ptr_ref  _Ty *_Ptr = _Right._Ref;  _Right._Ref = 0;    // release old  _Myptr = _Ptr;  // reset this  }  template<class _Other>  operator auto_ptr<_Other>() _THROW0()  {   // convert to compatible auto_ptr  return (auto_ptr<_Other>(*this));  }  /  //  当auto_ptr的拷贝构造函数以及赋值操作符函数的参数是auto_ptr-  //  右值引用对象时，该参数将被转换为 auto_ptr_ref  //  编译器正是通过调用下面的隐式类型转换函数来完成这一隐式转换的  /  template<class _Other>  operator auto_ptr_ref<_Other>() _THROW0()  {   // convert to compatible auto_ptr_ref  _Other *_Cvtptr = _Myptr;   // test implicit conversion  auto_ptr_ref<_Other> _Ans(_Cvtptr);  _Myptr = 0; // pass ownership to auto_ptr_ref  return (_Ans);  }  template<class _Other>  _Myt& operator=(auto_ptr<_Other>& _Right) _THROW0()  {   // assign compatible _Right (assume pointer)  reset(_Right.release());  return (*this);  }  template<class _Other>  auto_ptr(auto_ptr<_Other>& _Right) _THROW0()  : _Myptr(_Right.release())  {   // construct by assuming pointer from _Right  }  _Myt& operator=(_Myt& _Right) _THROW0()  {   // assign compatible _Right (assume pointer)  reset(_Right.release());  return (*this);  }  _Myt& operator=(auto_ptr_ref<_Ty> _Right) _THROW0()  {   // assign compatible _Right._Ref (assume pointer)  _Ty *_Ptr = _Right._Ref;  _Right._Ref = 0;    // release old  reset(_Ptr);    // set new  return (*this);  }  ~auto_ptr()  {   // destroy the object  delete _Myptr;  }  _Ty& operator*() const _THROW0()  {   // return designated value  #if _ITERATOR_DEBUG_LEVEL == 2  if (_Myptr == 0)  _DEBUG_ERROR("auto_ptr not dereferencable");  #endif /* _ITERATOR_DEBUG_LEVEL == 2 */  return (*get());  }  _Ty *operator->() const _THROW0()  {   // return pointer to class object  #if _ITERATOR_DEBUG_LEVEL == 2  if (_Myptr == 0)  _DEBUG_ERROR("auto_ptr not dereferencable");  #endif /* _ITERATOR_DEBUG_LEVEL == 2 */  return (get());  }  _Ty *get() const _THROW0()  {   // return wrapped pointer  return (_Myptr);  }  _Ty *release() _THROW0()  {   // return wrapped pointer and give up ownership  _Ty *_Tmp = _Myptr;  _Myptr = 0;  return (_Tmp);  }  void reset(_Ty *_Ptr = 0)  {   // destroy designated object and store new pointer  if (_Ptr != _Myptr)  delete _Myptr;  _Myptr = _Ptr;  }  private:  _Ty *_Myptr;    // the wrapped object pointer  };  

<Refer to>  http://blog.csdn.net/monkey_d_meng/article/details/5901392 &  http://blog.csdn.net/btwsmile/article/details/6819900