copy assignment operator in c++

The copy assignment operator in C++ is used to assign the values of one object to another object of the same class. It is a member function that is invoked when the assignment operator (=) is used to assign one object to another.

Here is an example of a copy assignment operator in C++:

class MyClass {
public:
    // Constructor
    MyClass(int value)
        : m_value(value)
    {
    }

    // Copy assignment operator
    MyClass& operator=(const MyClass& other)
    {
        if (this != &other) {
            m_value = other.m_value;
        }
        return *this;
    }

private:
    int m_value;
};

Let's go through each step in the copy assignment operator:

1. The copy assignment operator is declared as a member function of the class MyClass. It returns a reference to the object itself (MyClass&).

2. The copy assignment operator takes a constant reference to another object of the same class (const MyClass& other) as a parameter. This is the object whose values will be assigned to the current object.

3. Inside the copy assignment operator, a self-assignment check is performed using the this pointer. This check ensures that the assignment is not being done to the same object. If the objects are the same, no assignment is necessary, so the function simply returns a reference to the current object.

4. If the objects are not the same, the values of the member variables of the current object (m_value) are assigned the values of the corresponding member variables of the other object (other.m_value).

5. Finally, the copy assignment operator returns a reference to the current object (*this).

By implementing the copy assignment operator, you can assign one object to another object of the same class using the assignment operator (=). This allows you to create a new object with the same values as an existing object, or update the values of an existing object with the values of another object.