c++ - 制作模板类后不是类、命名空间、枚举？

Question

我正在尝试对一些类(LinkedListNode 和 LinkedList)进行模板化，这样

template <class T>
class LinkedListNode{
    public:
        T data;
        LinkedListNode *next;
        LinkedListNode();
};

---

在我的 LinkedList 类中，我有私有(private)变量:

private:
    LinkedListNode *head;
    //iterator for traversing the list
    LinkedListNode *current;

};

编译时出现奇怪的错误:

./LinkedList.h:38:3: error: unknown type name 'LinkedListNode'; did you mean 'LinkedList'? LinkedListNode *head; ^~~~~~~~~~~~~~ LinkedList ./LinkedList.h:13:7: note: 'LinkedList' declared here class LinkedList{ ^ ./LinkedList.h:40:3: error: unknown type name 'LinkedListNode'; did you mean 'LinkedList'? LinkedListNode *current; ^~~~~~~~~~~~~~ LinkedList ./LinkedList.h:13:7: note: 'LinkedList' declared here class LinkedList{ ^ LinkedList.cpp:7:1: error: 'LinkedListNode' is not a class, namespace, or enumeration LinkedListNode::LinkedListNode(){ ^ ./LinkedList.h:5:7: note: 'LinkedListNode' declared here class LinkedListNode{ ^

如果它说我的 LinkedListNode 也被声明，为什么我会收到这些错误？

Answer 1

LinkedListNode不是类型，而是 LinkedListNode<T>是。务必implement LinkedListNode::LinkedListNode() and other member functions in the header file , 和 #include此头文件在 LinkedList<T> 的定义之前.

template <class T>
class LinkedList
{
private:
    LinkedListNode<T> *head;
    LinkedListNode<T> *current;
}