智能指针的简单实现

来源：互联网发布：淘宝美工需要什么资质编辑：程序博客网时间：2024/05/16 07:06
share_ptr运用对每一个对象进行计数，从而防止资源泄露auto_ptr:template<class T>class AutoPtr{public:    AutoPtr(T* ptr)        :_ptr(ptr)    {}    ~AutoPtr()    {        if (_ptr)        {            cout << "delete" << _ptr << endl;            delete _ptr;            _ptr = NULL;        }    }    AutoPtr(AutoPtr<T>& ap)        :_ptr(ap._ptr)    {        ap._ptr = NULL;    }    AutoPtr& operator=(AutoPtr<T>& ap)    {        if (this != &ap)        {            delete _ptr;            _ptr = ap._ptr;            ap._ptr = NULL;        }        return *this;    }public:    T& operator*()    {        return *_ptr;    }    T* operator->()    {        return _ptr;    }    T* GetPtr()    {        return _ptr;    }protected:    T* _ptr;};share_prt:template<class T>class SharedPtr{public:    SharedPtr(T* ptr)            :_ptr(ptr)            , _pCount(new long(1))    {}    ~SharedPtr()    {        _Release();    }    SharedPtr(const SharedPtr<T> sp)        :_ptr(sp._ptr)        , _pCount(sp._pCount)    {        ++*_pCount;    }    //传统写法    //SharedPtr& operator=(const SharedPtr<T>& sp)    //{    //  if (_ptr != sp._ptr)    //  {    //      _Release();    //      _ptr = sp._ptr;    //      _pCount = sp._pCount;    //      ++*_pCount;    //  }    //  return *this;    //}    //现代写法    SharedPtr& operator=(SharedPtr<T> sp)    {        swap(_ptr, sp._ptr);        swap(_pCount, sp._pCount);        return *this;    }public:    T& operator*()    {        return *_ptr;    }    T* operator->()    {        return _ptr;    }    T* GetPtr()    {        return _ptr;    }    long GetCount()    {        return *_pCount;    }protected:    void _Release()    {        if (--*_pCount == 0)        {            delete _ptr;            delete _pCount;        }    }protected:    T* _ptr;    long* _pCount;};share_array:template<class T>class SharedArray{public:    SharedArray(T* ptr)        :_ptr(ptr)        , _pCount(new long(1))    {}    ~SharedArray()    {        _Release();    }public:    T& operator[](size_t index)    {        return _ptr[index];    }protected:    void _Release()    {        if (--*_pCount == 0)        {            delete[] _ptr;            delete _pCount;        }    }protected:    T* _ptr;    long* _pCount;};//#pragma once//#include<iostream>//#include<string>//template<class T>//class ScopedPtr//{//public://  ScopedPtr(T* ptr)//      :_ptr(ptr)//  {////  }//  ~ScopedPtr()//  {//      delete _ptr;//  }//  void Display()//  {//      cout << (*_ptr) << endl;//  }//  T& operator*()//  {//      //assert(_ptr);//      return *_ptr;//  }////  T* operator->()//  {//      return _ptr;//  }////  T* GetPtr()//  {//      return _ptr;//  }//protected://  T* _ptr;//private:// //  ScopedPtr(const ScopedPtr<T>& s);//  ScopedPtr& operator=(const ScopedPtr<T> s);//}；scorp_ptr:template < typename T >class ScopedPtr   {public:    ScopedPtr(T * ptr)        :_ptr(ptr)    {}    ~ScopedPtr()    {        if (NULL != this)        {            delete _ptr;            _ptr = NULL;        }    }protected:    ScopedPtr< T >(ScopedPtr < T>& ap);    ScopedPtr <T > opreator = (ScopedPtr & ap);  private:    T * _ptr;};#include<iostream>  using namespace std;int main(){    int* p = new int(1);    ScopedPtr<int> sp(p);    //ScopedPtr<int> sp1(sp);      return 0;}template<typename T>class ScopedPtrArray{public:    ScopedPtrArray(T* ptrArr = NULL)        :_ptrArr(ptrArr)    {}    ~ScopedPtrArray()    {        if (NULL != this)        {            delete[] _ptrArr;              _ptrArr = NULL;        }    }protected:    ScopedPtrArray<T>(ScopedPtrArray<T> & parr);    ScopedPtrArray& operator=(ScopedPtrArray<T> & parr);private:    T* _ptrArr;};#include<iostream>  using namespace std;int main(){    ScopedPtrArray<int> pa(new int[10]);    //ScopedPtrArray<int> pa1(pa);      return 0;}
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