Constructor Errors Between Classes

[StMick]

I'm building a LinkedList data structure with a nested Node class. The Node class within the LinkedList class looks like this:

    class Node {
    public:
        
        Node(){
            this->next = nullptr;
            this->prev = nullptr;
        }

        T data;
        Node* next;
        Node* prev;
    };

My main function looks like this:

#include <iostream>
#include "linked_list.h"

class Animal{
public:
    Animal(std::string str){
        this->name = str;
    }

    std::string getName(){
        return this->name;
    }

private:
    std::string name;
};

int main() {

    LinkedList<Animal>* AList = new LinkedList<Animal>(0);
    
    Animal* a = new Animal("Fluffy");

    AList->add_last(*a);

    return 0;
}

When I run this code, I get the following error:

error: no matching function for call to 'Animal::Animal()'
16 | Node(){
| ^
C:/LinkedListcpp/main.cpp:6:5: note: candidate: 'Animal::Animal(std::string)'
6 | Animal(std::string str){
| ^~~~~~
C:/LinkedListcpp/main.cpp:6:5: note: candidate expects 1 argument, 0 provided

Any ideas what is causing this problem?

[Peter87]

The data member of the Node class is "default-initialized" but Animal does not have a default constructor.

[helios]

Perhaps what you meant to do was

LinkedList<Animal *> AList;
AList.add_last(new Animal("Fluffy"));

This code looks suspiciously Java-ey. If I'm right and you already know Java, you should be careful about trying to import Java patterns into C++. The languages are not as similar as they appear superficially.