目前测试功能正常。若有不完善的地方在改进吧。时候不早了睡觉去，哎，翘课会被抓，不冒险了。晚安全世界O(∩_∩)O
1 /************************************************************************* 2 *my shared_ptr: share_ptr 3 *author:ERIC 4 *blog:http://www.ilovecpp.com 5 *time:2015-5-28 01:36:43 6 *************************************************************************/ 7 8 template <typename T> class share_ptr { 9 private: 10 T* __ptr; 11 int* __pcounts; 12 public: 13 share_ptr(T* p= NULL); 14 share_ptr(const share_ptr<T>& src); 15 share_ptr& operator=(share_ptr<T>& src); 16 ~share_ptr(); 17 operator bool() const;//支持if(p)形式 18 T* operator-> () const; 19 T& operator*() const; 20 T* get() const; 21 int use_counts() const;//返回引用计数 22 bool unique() const;//当前智能指针是否唯一 23 void swap(share_ptr& rhs);//交换，成员函数 24 template <typename Type>//友元函数，交换两个智能指针 25 friend void swap(share_ptr<Type>& lhs,share_ptr<Type>& rhs); 26 }; 27 28 template<typename T> 29 share_ptr<T>::share_ptr(T* p) 30 :__ptr(p),__pcounts(new int(0)) 31 { 32 if(__ptr) 33 *__pcounts = 1; 34 } 35 36 template<typename T> 37 share_ptr<T>::~share_ptr() 38 { 39 --*__pcounts; 40 if(*__pcounts == 0) 41 {//空智能指针这里delete __ptr也安全，delete NULL; 42 delete __pcounts; 43 delete __ptr; 44 } 45 } 46 47 /*__ptr(new T(src)) 很重要 ，如果直接__ptr(new T) 48 *会由于T类没有默认构造函数而出错 49 *测试的时候才发现这个问题的 50 */ 51 template<typename T> 52 share_ptr<T>::share_ptr (const share_ptr<T>& src) 53 :__pcounts(new int),__ptr(new T(src)) 54 { 55 ++*src.__pcounts; 56 __ptr = src.__ptr; 57 __pcounts = src.__pcounts; 58 } 59 60 template <typename T> 61 share_ptr<T>& share_ptr<T>::operator= (share_ptr<T>& src) 62 { 63 --*__pcounts; 64 //如果是空智能指针的话 __pcounts == -1,那块内存也得释放 65 if(*__pcounts == 0 || *__pcounts == -1) 66 delete __pcounts; 67 ++*src.__pcounts; 68 __ptr = src.__ptr; 69 __pcounts = src.__pcounts; 70 return *this; 71 } 72 73 //支持if(p)这样的操作 74 template<typename T> 75 share_ptr<T>::operator bool() const 76 { 77 return __ptr; 78 } 79 80 template<typename T> 81 T* share_ptr<T>::operator->() const 82 { 83 return __ptr; 84 } 85 86 template<typename T> 87 T& share_ptr<T>::operator*() const 88 { 89 return *__ptr; 90 } 91 92 93 template<typename T> 94 T* share_ptr<T>::get() const 95 { 96 return __ptr; 97 } 98 99 template<typename T> 100 int share_ptr<T>::use_counts() const 101 { 102 return *__pcounts; 103 } 104 105 template<typename T> 106 bool share_ptr<T>::unique() const 107 { 108 if(*__pcounts == 1) 109 return true; 110 else 111 return false; 112 } 113 114 template<typename T> 115 void share_ptr<T>::swap(share_ptr<T>& rhs) 116 { 117 T* tmpPtr = rhs.__ptr; 118 rhs.__ptr = __ptr; 119 __ptr = tmpPtr; 120 int* tmpPcounts = rhs.__pcounts; 121 rhs.__pcounts = __pcounts; 122 __pcounts = tmpPcounts; 123 } 124 125 template<typename T> 126 void swap(share_ptr<T>& lhs,share_ptr<T>& rhs) 127 { 128 T* tmpPtr = rhs.__ptr; 129 rhs.__ptr = lhs.__ptr; 130 lhs.__ptr = tmpPtr; 131 int* tmpPcounts = rhs.__pcounts; 132 rhs.__pcounts = lhs.__pcounts; 133 lhs.__pcounts = tmpPcounts; 134 } 135 136 //c++11 make_shared<T>(args) 137 template<typename T> 138 share_ptr<T> make_share(T args) 139 { 140 return new T(args); 141 }