智能指针与弱引用详解

class SmartPtr{

public:

SmartPtr(T *p = 0):ptr(p){count = new int(1) ;}// 第一次创建的时候，引数肯定是1

SmartPtr(const SmartPtr & rhs):ptr(rhs.ptr),count(rhs.count){++*rhs.count ;}

T ＆operator*(){return *ptr}

T* operator->(){return ptr}

SmartPtr ＆operator=(const SmartPtr & rhs){

if(ptr == rhs.ptr)

return *this ;

if(--*count == 0){

delete ptr ;

delete count ;

}

++*rhs.count ;

count = rhs.count ;

ptr = rhs.ptr ;

}

~SmartPtr(){

if(--*count==0)

delete ptr ;

delete count ;

}

private:

T ＊ptr ;

int ＊count ;