c++ copy assignment and move assignment are not being called

Question

I am trying to implement copy and move assignments, but I don't understand how should I use them. I have read the following topic
When did copy assignment operator called?
But it did not work for me.

Class:

class Directory{

    string name;
public:
        Directory(string name):name(name) {

        }
        ~Directory() {
            cout << "Deleting was called" <<endl;

            }

        Directory& operator=(Directory& other){
            cout << "cp assigment" <<endl;
            return *this;
        }
        Directory& operator=(Directory&& other){
            cout << "move assigment" <<endl;
            return *this;
        }
};

Main

int main()
{

    Directory* dir = new Directory("alex");
    Directory* dir2;
    dir = dir2;

    cout<<"done"<<endl;
};

I would like to know when the copy assignment and move assignment are called. Thanks in advance.

Answer 1

I my first comment, I recommended to remove all *s and the new.

Hence the main function becomes:

int main()
{
  Directory dir = Directory("alex");
  Directory dir2;
  dir2 = dir; // <-- fixed, original was: dir = dir2;

  cout<<"done"<<endl;
  return 0; // <-- fixed, return is strictly recommended for every non-void function
}

Compiling...

Error: Something is wrong in Directory dir = Directory("alex"); (usage of deleted copy constructor).

The copy-constructor is used to initialize dir with the temporary instance created by Directory("alex").

This is easy to change:

int main()
{
  Directory dir("alex"); // <-- fixed: direct construction
  Directory dir2;
  dir2 = dir;

  cout<<"done"<<endl;
  return 0;
}

Compiling...

Error: Something is wrong in Directory dir2;.

A yepp. You defined constructor Directory(string name);. This suppresses the auto-creation of the default constructor which would be needed here.

We either could add the default constructor to class Directory:

  Directory() = default;

or we can improve the existing non-default constructor so that it can be used as default constructor as well:

  Directory(string name = string()): name(name) { }

The whole source:

#include <iostream>
#include <string>
using namespace std;

class Directory{

    string name;
public:
        Directory(string name = string()):name(name) {

        }
        ~Directory() {
            cout << "Deleting was called" <<endl;

            }

        Directory& operator=(Directory& other){
            cout << "cp assigment" <<endl;
            return *this;
        }
        Directory& operator=(Directory&& other){
            cout << "move assigment" <<endl;
            return *this;
        }
};

int main() {
    //Directory dir = Directory("alex");
    Directory dir("alex");
    Directory dir2;
    dir2 = dir;

    cout<<"done"<<endl;
    // your code goes here
    return 0;
}

Now, it compiles and works.

Output:

cp assigment
done
Deleting was called
Deleting was called

You can see it live on ideone.