c++ - 实现智能指针类时出错

Question

我卡在了一个错误上。这是我的代码:

 template<class t>
 class smart_ptr{
    t *ptr;
 public: 
    smart_ptr(t *p):ptr(p){cout<<"smart pointer copy constructor is called"<<endl;} 

    ~smart_ptr(){cout<<"smart pointer destructor is called"<<endl;delete(ptr);}
    t& operator *(){cout<<"returning the * of pointer"<<endl;return(*ptr);}
    t* operator ->(){cout<<"returning the -> of pointer"<<endl;return(ptr);}
    t* operator=(const t &lhs){ptr=lhs;cout<<"assignement operator called"<<endl;}
   };
   class xxx{
            int x;
    public:
            xxx(int y=0):x(y){cout<<"xxx constructor called"<<endl;}
            ~xxx(){cout<<"xxx destructor is called"<<endl;}
            void show(){cout<<"the value of x="<<x<<endl;}
    };
 int main(int argc, char *argv[])
 {
    xxx *x1=new xxx(50);
    smart_ptr<xxx *> p1(x1);
    return 0;
 }

编译时出现以下错误

smart_pointer_impl.cpp: 在函数‘int main(int, char**)’中:

smart_pointer_impl.cpp:27: 错误:没有匹配函数来调用‘smart_ptr::smart_ptr(xxx*&)’

smart_pointer_impl.cpp:7:注意:候选者是:smart_ptr::smart_ptr(t*) [with t = xxx*]

smart_pointer_impl.cpp:4: 注意:smart_ptr::smart_ptr(const smart_ptr&)

欢迎提供解决方案的任何帮助。

Answer 1

大概是smart_ptr是template<class t>然后主要是smart_ptr<xxx>而不是 smart_ptr<xxx*> ？