c++ - 结构和模板功能

Question

我刚刚开始使用模板，并想以这种方式在头文件中实现它，但是我遇到了各种各样的错误，并且并不清楚为什么。

头文件:

#ifndef EXAM3_H_
#define EXAM3_H_

#include <iostream>
#include <fstream>
#include <iomanip>
#include <string>

using namespace std;

const int maxInt = 2147483647;

template <typename T>

struct nodeType {
    T data;
    nodeType *next;
};

bool search(nodeType *head, const T &searchItem);
void deleteNode(nodeType *&head, nodeType *&tail, int &count, const T &deleteItem);
void initializeList(nodeType *&head, nodeType *&tail, int &count);
bool isEmptyList(const nodeType *head);
void printList(nodeType *head);
int lengthList(nodeType *head);
void destroyList(nodeType *&head, nodeType *&tail, int &count);
void insert(const T &newItem, nodeType *&head, nodeType *&tail, int &count);

#endif

错误:

Answer 1

我认为您忘了输入class list或类似的内容

#ifndef EXAM3_H_
#define EXAM3_H_

#include <iostream>
#include <fstream>
#include <iomanip>
#include <string>

using namespace std;

const int maxInt = 2147483647;

template <typename T>
class list{
public:    
    struct nodeType {
        T data;
        nodeType *next;
    };

    bool search(nodeType *head, const T &searchItem);
    void deleteNode(nodeType *&head, nodeType *&tail, int &count, const T &deleteItem);
    void initializeList(nodeType *&head, nodeType *&tail, int &count);
    bool isEmptyList(const nodeType *head);
    void printList(nodeType *head);
    int lengthList(nodeType *head);
    void destroyList(nodeType *&head, nodeType *&tail, int &count);
    void insert(const T &newItem, nodeType *&head, nodeType *&tail, int &count);
};
#endif

但是，如果这些函数不是成员函数，那么您错了，因此请按如下所示编写它们

template<typename T>
bool search(nodeType <T> *head, const T &searchItem);
template<typename T>
void deleteNode(nodeType <T> *&head, nodeType <T> *&tail, int &count, const T &deleteItem);
template<typename T>
void initializeList(nodeType <T> *&head, nodeType <T> *&tail, int &count);
template<typename T>
bool isEmptyList(const nodeType <T> *head);
template<typename T>
void printList(nodeType <T> *head);
template<typename T>
int lengthList(nodeType <T> *head);
template<typename T>
void destroyList(nodeType <T> *&head, nodeType <T> *&tail, int &count);
template<typename T>
void insert(const T &newItem, nodeType <T> *&head, nodeType <T> *&tail, int &count);