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Question

如果我想在列表中添加实例，我无法理解如何在main中调用add函数。

#include "object.h"
class list {

private:
struct Node
{
object objectInfo;
Node *next;

};


int size;
Node *head;


public:

list();
list(const list& otherlist);
~list();

void Add(const Node myObject);

我的主要

int main() {
object myObject;

myObject.setTitle("Object 1");
myObject.setPrice(78.58);
myObject.setISBN("515161611");


cout << myObject << endl;

list myList;

myList.Add(myObject);


return 0;

}

我在cpp中的功能

void list::Add(const Node myObject) {

Node* temp;
temp = new Node; 
temp->objectInfo = myObject.objectInfo;
temp->next = head; 


head = temp;
size++; 

}

我在这行上遇到麻烦myList.Add（myObject）; 继续说空列表::添加（常量列表＆amp;）'：不能将参数1从'对象'转换为'常量列表::节点'

也没有重载函数的实例“list :: Add”匹配参数列表

Answer 1

您正在尝试将类型为object的对象传递给采用Node类型参数的函数。 const Node myObject应该是const对象myObject。

Answer 2

这可能会给你一些想法：

#include <iostream>
#include <string>

template <typename Object>
class List {
    class Node : public Object {
        //static int& count() { static int c=0; return c; }
    public:
        Node* next;
        Node() : next(nullptr) { 
            //std::cout << ++count() << " Nodes\n"; 
        }
        Node(const Object& obj) : next(nullptr), Object(obj) { 
            //std::cout << ++count() << " Nodes\n";
        }
        ~Node() {
            //std::cout << --count() << " Nodes\n";
        }
    };

    Node *head, *tail;
    int size;

public:
    class iterator {
        Node *cur_node;
    public:
        iterator(Node* node) { cur_node = node; }
        Object& operator * () const { return *cur_node; }
        bool operator != (const iterator& iter) const { return iter.cur_node != cur_node; }
        iterator& operator ++() { if(cur_node) cur_node = cur_node->next; return *this;  }
    };
    class iterator_const {
        const Node *cur_node;
    public:
        iterator_const(const Node* node) { cur_node = node; }
        const Object& operator * () const { return *cur_node; }
        bool operator != (const iterator_const& iter) const { return iter.cur_node != cur_node; }
        iterator_const& operator ++() { if(cur_node) cur_node = cur_node->next; return *this; }
    };

    iterator       begin()       { return iterator(head); }
    iterator       end()         { return iterator(nullptr); }
    iterator_const begin() const { return iterator_const(head); }
    iterator_const end()   const { return iterator_const(nullptr); }

    template <typename ...Args>
    void Add(const Object& obj, Args...more) {
        Node *new_node = new Node(obj);
        ++size;
        if(!tail) { tail = head = new_node; }
        else      { tail->next = new_node; tail = new_node; }
        Add(more...);
    }
    void Add() {}

    int Size() const { return size; }

    List() : head(nullptr), tail(nullptr), size(0) {}
    List(const List& src) : head(nullptr), tail(nullptr), size(0) {
        for(auto&& entry : src) {
            Add(entry);
        }
    }
    ~List() {
        Node* p = head;
        while(p) {
            Node* next = p->next;
            delete p;
            p = next;
        }
    }
};

struct MyObjectType {
    std::string name;
    int         age;
    MyObjectType(std::string name, int age) : name(name), age(age) {}
    friend std::ostream& operator << (std::ostream& os, const MyObjectType& obj) {
        return os << "{\"" << obj.name << "\":" << obj.age << "}";
    }
};

template <typename T>
void PrintList(const List<T>& list) {
    std::cout << "Size: " << list.Size() << "\n";
    for(const auto &elem : list) {
        std::cout << "    " << elem << "\n";
    }
}

int main() {
    using MyList = List<MyObjectType>;

    MyList list_one;
    list_one.Add(
        MyObjectType("Harry",32),
        MyObjectType("Lisa", 66),
        MyObjectType("Buddy", 2),
        MyObjectType("Skippy", 21)
    );

    MyList list_two(list_one);
    list_two.Add(
        MyObjectType("Horse", 10),
        MyObjectType("Mule", 11)
    );

    std::cout << "list_one:\n";
    PrintList(list_one);
    std::cout << '\n';
    std::cout << "list_two:\n";
    PrintList(list_two);
}