我正在尝试重载<<运算符,但我遇到了一些这样的错误:
传递const std :: ostream'asthis'的参数`std :: basic_ostream <_CharT,_Traits>&std :: basic_ostream <_CharT,_Traits> :: operator <<(const void *)[with _CharT = char,_Traits = std :: char_traits]'丢弃限定符
这是我的代码:
#include<iostream>
using namespace std;
class nod{
protected:
int info;
nod *next;
friend class lista;
friend const ostream &operator<<(const ostream &,lista&);
};
class lista
{nod *first, *last;
public:
lista()
{first=new nod;
last=new nod;
first=last=NULL;}
void insert(int);
// void remove();
void afisare();
nod *get_first(){ return first;};
};
void lista::insert(int x)
{ nod *nou=new nod;
nou->info=x;
if(!first)
first=last=nou;
else
nou->next=first;
first=nou;
last->next=first;}
const ostream &operator<<(const ostream &o,lista &A)
{nod *curent=new nod;
o<<"Afisare: ";
curent=A.get_first();
if(curent)
o<<curent->info<<" ";
curent=curent->next;
while(curent!=A.get_first())
{o<<curent->info<<" ";
curent=curent->next;}
return o;
}
int main()
{lista A;
A.insert(2);
A.insert(6);
A.insert(8);
A.insert(3);
A.insert(5);
cout<<A;
system("pause");
return 0;}
1 回答
这个const ostream&operator <<(const ostream&o,lista&A)
应该:
因为在写入时会修改实际流 .