<分区>
我正在实现一个单向链表。这是节点类
template <typename T> class node{
friend class slist<T>;
public:
explicit node():data(0), next(NULL){}
private:
T data;
node<T> *next;
};
这是列表类。
template<typename T> class slist{
public:
slist():head(NULL){}
bool empty(){
return head == NULL;
}
void add_front(const T& data){
if(head == NULL){
node<T>* n = new node<T>();
n->data = data;
n->next = NULL;
head = n;
return;
}
node<T>* n = new node<T>();
n->data = data;
n->next = head;
head = n;
}
void remove_front(){
if(head == NULL) return;
node<T>* old = head;
head = old->next;
delete old;
}
void print_list(){
if(head == NULL) return;
while(!empty()){
std::cout<<head->data<<std::endl;
head = head->next;
}
}
~slist(){
while(!empty()) remove_front();
}
private:
node<T>* head;
};
如果我将节点中的成员声明为公共(public)的,则实现工作得很好。然而,当我将它们声明为私有(private)并将 slist 设为友元类时,我收到以下错误。
In file included from src.cpp:3:
./slist.hpp:5:28: error: redefinition of 'slist' as different kind of symbol
template<typename T> class slist{
^
./node.hpp:4:15: note: previous definition is here
friend class slist;
我显然可以找到单链表的其他实现,但我试图了解这里出了什么问题。因此,请不要将未经请求的建议称为“google it”。谢谢。